30
WP4C Dew Point PotentiaMeter Operator’s Manual METER Group, Inc. Version: April 16, 2018 — 09:16:14
WP
4C
Dew
Point
PotentiaM
eter
Operator’sMan
ual
ME
TE
RG
rou
p,
Inc.
Ver
sion
:A
pri
l16
,20
18—
09:1
6:14
WP
4C
ME
TE
RG
rou
p,
Inc.
2365N
EH
opkin
sC
ourt
Pu
llman
WA
99163
Ph
one:
509-332-5600F
ax:
509-332-5158W
ebsite:
ww
w.m
etergroup
.comE
mail:
sup
port.en
viron
men
t@m
etergrou
p.com
orsales.en
viron
men
t@m
etergroup
.com
Tra
dem
ark
sc©
2018M
ET
ER
Grou
p,
Inc.
All
Righ
tsR
eserved
ii
IND
EX
WP
4C
Dri
ver,
28In
terf
ace
Cab
le,
27
Vap
orP
ress
ure
,30,
31V
erifi
cati
onS
tan
dar
ds,
19L
ong
Rea
dT
imes
for,
42W
ate
rP
oten
tial
too
Hig
h/L
ow,
42
War
m-U
p,
10W
arra
nty
,2
Wat
erC
onte
nt,
30vs
Wat
erP
oten
tial
,30
Wat
erP
oten
tial
,30
Defi
nit
ion
,5
Dis
pla
yed
,8
Equ
atio
n,
30M
easu
rem
ent,
30T
heo
ry,
30W
P4C an
dT
emp
erat
ure
,6
Ch
ille
dM
irro
rD
ewP
oint
Tec
h-
niq
ue,
5Im
por
tant
Tip
s,16
Mea
suri
ng
Wat
erP
oten
tial
,30
Pre
par
ing
for
Op
erat
ion
,8
Th
eory
,30
WP
4CR
ead
ings
Cau
tion
s,26
54
WP
4C
CO
NT
EN
TS
Conte
nts
1In
trod
ucti
on
11.
1C
ust
omer
Sup
por
t.
..
..
..
..
..
..
..
..
..
.1
1.2
Ab
out
Th
isM
anu
al.
..
..
..
..
..
..
..
..
..
21.
3W
arra
nty
..
..
..
..
..
..
..
..
..
..
..
..
.2
1.4
Sel
ler’
sL
iab
ilit
y.
..
..
..
..
..
..
..
..
..
..
.2
2A
bou
tth
eW
P4C
42.
1S
pec
ifica
tion
s.
..
..
..
..
..
..
..
..
..
..
..
42.
2W
P4C
and
Wat
erP
oten
tial
..
..
..
..
..
..
..
.5
2.3
How
the
WP
4Cw
orks
..
..
..
..
..
..
..
..
..
52.
4W
P4C
and
Tem
per
atu
re.
..
..
..
..
..
..
..
..
6
3G
ett
ing
Sta
rted
73.
1C
omp
onen
tsof
you
rW
P4C
..
..
..
..
..
..
..
.7
3.2
Ch
oos
ing
aL
oca
tion
..
..
..
..
..
..
..
..
..
.7
3.3
Fea
ture
s.
..
..
..
..
..
..
..
..
..
..
..
..
.8
3.4
Pre
par
ing
the
WP
4Cfo
rO
per
atio
n.
..
..
..
..
..
83.
5P
ort
abil
ity
..
..
..
..
..
..
..
..
..
..
..
..
.9
4T
he
Menu
s11
4.1
Th
eM
ain
Men
u.
..
..
..
..
..
..
..
..
..
..
.11
4.1.
1C
han
gin
gL
angu
ages
..
..
..
..
..
..
..
.11
4.1.
2R
ead
ing
Mod
es.
..
..
..
..
..
..
..
..
.12
4.2
Syst
emC
onfi
gura
tion
..
..
..
..
..
..
..
..
..
144.
3S
amp
leE
qu
ilib
rati
onS
cree
n.
..
..
..
..
..
..
..
17
5C
ali
bra
tion
an
dV
eri
ficati
on
19
5.1
Ver
ifica
tion
..
..
..
..
..
..
..
..
..
..
..
..
195.
2V
erifi
cati
onS
tan
dar
ds
..
..
..
..
..
..
..
..
..
195.
3W
hen
toV
erif
yC
alib
rati
on.
..
..
..
..
..
..
..
195.
4H
owto
Ver
ify
and
Cal
ibra
teth
eW
P4C
..
..
..
..
20
6S
am
ple
Pre
para
tion
22
6.1
Ch
oos
ing
aS
amp
leC
up
..
..
..
..
..
..
..
..
.22
6.2
Pre
par
ing
the
Sam
ple
..
..
..
..
..
..
..
..
..
226.
3D
ryS
amp
les
..
..
..
..
..
..
..
..
..
..
..
.23
6.4
Sam
ple
san
dT
emp
erat
ure
..
..
..
..
..
..
..
..
246.
5M
easu
rin
gP
lant
Sam
ple
s.
..
..
..
..
..
..
..
.25
iii
WP
4C
IND
EX
Sp
anish
,11
Sw
edish
,11
LeafM
easurin
gW
ater
Poten
tialin
Con
tinu
ous
Mod
e,13
LE
D,
14,44
Lin
earO
ffset
Ad
justin
gfor,
20L
oaner
Serv
ice,39
Location
forR
eadin
g,
7
Main
Men
u,
8,11
Main
tenan
ce,33
Matric
Poten
tial,30
Men
uMain
Men
u,
11S
ystem
Con
figu
ration,
14M
olalityV
erification
Stan
dard
s,19
Osm
oticP
otential,
30,32
Peltier
Cooler,
5P
hon
eN
um
ber,
iiP
lant
Sam
ples,
25P
ortability,
9P
reparin
gS
altS
olution
s,48
Pressu
reP
otential,
30
Read
Tim
eA
ffected
by
Sam
ple
Tem
per-
ature,
24L
ong,
40,41
Read
ing
Mod
es,12
Con
tinu
ous,
13F
ast,
13P
recise,12
Read
ings
Cau
tions,
26
How
WP
4CT
akes,25
Tak
ing
Read
ings,
25R
eferences,
46R
epairC
osts,39
Instru
ction
s,38
Sh
ipp
ing,
38
Sam
ple
Dry
Water
Poten
tial,23
Not
atR
oom
Tem
peratu
re,24
Prep
aration,
22
Slow
Water
Em
itting,
41S
pillin
g,26
Too
Dry,
42
Too
Hot,
26
Sam
ple
Cu
ps
Clean
ing,
22F
illing,
22S
ealing,
22S
amp
leE
qu
ilibration
Screen
,17
Satu
ratedS
alts,48
Seller’s
Liab
ility,2
Sen
sorP
erforman
ceS
creen,
44S
pecifi
cations,
4
Tech
nical
Su
pp
ort,1
Tem
peratu
reE
ffect
onW
aterP
otential,
31H
otS
amp
les,26
Imp
acton
Read
ings,
6In
strum
ent,
26
Sam
ples
not
at
Room
Tem
-p
erature,
24
Settin
g,15
Trian
gle,40,
43T
roub
leshootin
g,40
US
B
53
CO
NT
EN
TS
WP
4C
6.6T
akin
ga
Read
ing
..
..
..
..
..
..
..
..
..
..
.25
6.7H
owW
P4C
takesR
eadin
gs.
..
..
..
..
..
..
..
25
7C
om
pu
ter
Inte
rface
27
7.1A
qu
aLin
k4
Softw
are.
..
..
..
..
..
..
..
..
..
277.2
Usin
ga
Com
mu
nication
Program
..
..
..
..
..
..
28
8T
heory
:W
ate
rP
ote
ntia
l30
8.1W
aterP
otential
..
..
..
..
..
..
..
..
..
..
..
30
8.2M
easurin
gW
aterP
otential
..
..
..
..
..
..
..
.30
8.3E
ffect
ofT
emp
erature
onW
aterP
otential
..
..
..
.31
8.4E
stimatin
gO
smotic
Poten
tial.
..
..
..
..
..
..
.32
9C
lean
ing
an
dM
ain
ten
an
ce
33
9.1A
ccessing
the
Blo
ck.
..
..
..
..
..
..
..
..
..
339.2
Clean
ing
Pro
cedu
re.
..
..
..
..
..
..
..
..
..
.34
9.3C
heck
ing
Calib
ration.
..
..
..
..
..
..
..
..
..
37
10
Rep
air
Instru
ctio
ns
38
10.1S
hip
pin
gD
irections
..
..
..
..
..
..
..
..
..
..
38
10.2R
epair
Costs
..
..
..
..
..
..
..
..
..
..
..
.39
10.3L
oaner
Serv
ice.
..
..
..
..
..
..
..
..
..
..
.39
11
Tro
ub
lesh
ootin
g40
11.1P
roblem
san
dS
olution
s.
..
..
..
..
..
..
..
..
4011.2
Sen
sorP
erforman
ceS
creen.
..
..
..
..
..
..
..
44
12
Fu
rther
Read
ing
46
12.1A
pp
licationN
otes.
..
..
..
..
..
..
..
..
..
.46
13
Ap
pen
dix
A48
13.1P
reparin
gS
altS
olution
s.
..
..
..
..
..
..
..
..
48
14
Ap
pen
dix
B49
15
Decla
ratio
nof
Con
form
ity50
16
Certifi
cate
of
Tra
ceab
ility51
iv
Ind
ex
Acc
esso
ries
,7
Ap
pli
cati
onN
otes
,46
Aqu
aLin
k4
Sof
tware
,27
Bee
per
,14
,44
Blo
ckF
ailu
re,
40,
43B
lock
Sen
sors
,33
Bu
tton
sM
enu
Sel
ecti
on,
11
Cfo
rC
onti
nu
ous
Mod
e,13
Cal
ibra
tion
Ch
ange
sIn
,19
Ch
eckin
g,37
Dri
ft,
19M
enu
,15
Ste
ps,
20W
hen
toC
hec
k,
19C
auti
ons,
26C
EC
omp
lian
ce,
50C
erti
fica
teof
Tra
ceab
ilit
y,51
Ch
ille
dM
irro
rT
ech
niq
ue,
5C
lean
ing,
33In
sid
eC
ase,
36In
sid
eC
ham
ber
,34
Op
tica
lS
enso
r,35
Sen
sor
Blo
ck,
33T
her
mop
ile,
36C
omp
onen
ts,
7C
omp
ute
rIn
terf
ace,
27C
onta
ctIn
form
ati
on,
1C
otto
nS
wab
sN
otfo
rC
lean
ing,
33C
ust
omer
Su
pp
ort,
1
Dec
aTer
mP
rogr
am,
28
Dec
lara
tion
ofC
onfo
rmit
y,50
Dir
tyM
irro
rIn
dic
ato
r,26
Dis
till
edW
ater
,19
Dry
Sam
ple
s,23
,42
Dry
Wat
erP
ote
nti
al,
23
Em
ail,
1,51
Err
orM
essa
ges,
40E
xit
,15
Fan
Insi
de
Sam
ple
Ch
amb
er,
31F
axN
um
ber
,ii
Fea
ture
s,8
Fie
ldM
easu
rem
ents
,9
Fu
rth
erR
ead
ing,
46F
use
Ch
angi
ng,
41
Gra
vit
atio
nal
Pote
nti
al,
30
Hyp
erte
rmin
al,
28
KC
lS
tand
ard
s,19
Lan
guag
esC
han
gin
g,11
Cze
ch,
11D
anis
h,
11F
inn
ish
,12
Fre
nch
,11
Ger
man
,11
Ital
ian
,11
Jap
anes
e,11
Nor
weg
ian
,11
Pol
ish
,11
Por
tugu
ese,
11
52
WP
4C
1IN
TR
OD
UC
TIO
N
1In
trod
uct
ion
Wel
com
eto
ME
TE
R’s
WP
4CD
ewP
oint
Pot
enti
aM
eter
,th
ere
sear
chst
and
ard
for
mea
suri
ng
wat
erp
oten
tial
.W
P4C
isth
efa
stes
t,m
ost
accu
rate
,an
dm
ost
reli
able
inst
rum
ent
avai
lab
lefo
rm
easu
rin
gw
ate
rp
oten
tial
usi
ng
the
chil
led
-mir
ror
dew
poi
nt
tech
niq
ue.
Th
eW
P4C
suit
sth
en
eed
sof
the
scie
nti
stan
dst
ud
ent.
Itis
easy
tou
sean
dp
rovid
esfa
st,
accu
rate
resu
lts.
We
hop
eyo
ufi
nd
this
man
ual
info
r-m
ativ
ean
dh
elp
fulin
un
der
stan
din
gh
owto
max
imiz
eth
eca
pab
ilit
ies
ofyo
ur
WP
4C
.
1.1
Cu
stom
er
Su
pp
ort
Th
ere
are
seve
ral
way
sto
conta
ctM
ET
ER
ifyo
uev
ern
eed
ass
is-
tan
cew
ith
you
rp
rod
uct
,h
ave
any
qu
esti
ons,
orfe
edb
ack.
ME
TE
Rh
asC
ust
omer
Ser
vic
eR
epre
senta
tive
sav
aila
ble
tosp
eak
wit
hyo
uM
ond
ayth
rou
ghF
rid
ay,
bet
wee
n7
aman
d5
pm
Pac
ific
tim
e.
Note
:If
you
pu
rchase
dyo
ur
WP
4C
thro
ugh
adis
trib
uto
r,ple
ase
con
tact
them
for
ass
ista
nce
.
Em
ail:
sup
por
t.en
vir
onm
ent@
met
ergr
oup
.com
orsa
les.
envir
onm
ent@
met
ergr
oup
.com
Ph
one:
509-
332-
5600
Fax
:50
9-33
2-51
58
Ifco
nta
ctin
gu
sby
emai
lor
fax,
ple
ase
incl
ud
eas
part
ofyou
rm
es-
sage
you
rin
stru
men
tse
rial
nu
mb
er,
you
rn
ame,
add
ress
,p
hon
e,fa
xnu
mb
er,
an
da
des
crip
tion
ofyo
ur
pro
ble
mor
qu
esti
on.
1
WP
4C
16C
ER
TIF
ICA
TE
OF
TR
AC
EA
BIL
ITY
16
Certifi
cate
of
Tra
ceab
ility
ME
TE
RG
rou
p,
Inc.
2365N
EH
opkin
sC
ourt
Pu
llman
WA
99163U
SA
Tel:
509-332
-5600
Fax
:509
-332-5158
sup
port.en
viron
men
t@m
etergroup
.com
Th
isN
IST
sealcertifi
esth
atM
ET
ER
Grou
p,
Inc.
man
ufactu
resall
WP
4CD
ewP
oint
Poten
tiaMeters
accordin
gto
temp
erature
stan-
dard
sw
ithca
libra
tiontraceab
leto
the
Nation
alIn
stitute
ofS
tan-
dard
san
dT
echn
ology(N
IST
).
51
1IN
TR
OD
UC
TIO
NW
P4C
1.2
Ab
ou
tT
his
Manu
al
Please
readth
esein
struction
sb
eforeop
erating
you
rP
otentia
Meter
toen
sure
that
itp
erforms
atfu
llp
otential.
Th
ism
anu
alin
clud
esin
struction
sfor
setting
up
,calib
rating,
and
main
tain
ing
the
WP
4C.
Please
readth
esein
struction
sb
eforeop
erating
WP
4Cto
ensu
reth
at
the
instru
men
tp
erforms
toits
full
poten
tial.T
his
man
ual
will
aiden
du
sersin
un
derstan
din
gth
eb
asiccon
cepts
ofw
aterp
otential
and
enab
leth
emto
use
our
instru
men
tw
ithcon
fid
ence.
Every
effort
has
been
mad
eto
ensu
reth
atth
econ
tent
ofth
ism
anu
al
isco
rrectan
dscien
tifically
sound
.
1.3
Warra
nty
Th
isd
evice
has
a30-d
aysatisfaction
guaran
teean
da
one-year
war-
ranty
onp
artsan
dlab
or.Y
our
warran
tyis
autom
atica
llyva
lidated
up
onreceip
tof
the
instru
men
t.
1.4
Selle
r’sL
iab
ility
Seller
warran
tsn
eweq
uip
men
tof
itsow
nm
anu
facture
again
std
e-fective
work
man
ship
and
materials
fora
perio
dof
one
year
fromth
ed
ateof
receipt
ofeq
uip
men
t.
Note:
We
do
not
con
sider
the
results
of
ord
inary
wea
ran
dtea
r,n
eglect,m
isuse,
or
accid
ent
as
defects.
Th
eS
eller’sliab
ilityfor
defective
parts
shall
inn
oeven
tex
ceedth
efu
rnish
ing
ofrep
lacemen
tp
arts“freigh
ton
board
”th
efactory
wh
ereorigin
allym
anu
factured
.M
aterialan
deq
uip
men
tcovered
hereb
yw
hich
isn
otm
anu
factured
by
Seller
shall
be
coveredon
lyby
the
warran
tyof
itsm
anu
facturer.
Seller
shall
not
be
liable
toB
uyer
for
loss,dam
ageor
inju
riesto
person
s(in
clud
ing
dea
th),
orto
pro
perty
or
thin
gsof
wh
atsoever
kin
d(in
clud
ing,
bu
tn
otw
ithou
tlim
itation
,loss
ofan
ticipated
profi
ts),occasion
edby
orarisin
gou
tof
the
instal-
lation,
operation
,u
se,m
isuse,
non
use,
repair,
orrep
lacemen
tof
saidm
aterialan
deq
uip
men
t,or
out
ofth
euse
ofan
ym
ethod
orp
rocess
2
15D
EC
LA
RA
TIO
NO
FC
ON
FO
RM
ITY
WP
4C
15
Decl
ara
tion
of
Con
form
ity
Ap
pli
cati
onof
Cou
nci
lD
irec
tive
:20
04/1
08/E
Can
d20
11/
65/E
U
Sta
nd
ard
sto
wh
ich
con
form
ity
isd
ecla
red
:E
N61
326-
1:2
013
and
EN
5058
1:201
2
Man
ufa
ctu
rer’
sN
ame:
ME
TE
RG
roup
,In
cU
SA
2365
NE
Hop
kin
sC
t.P
ull
man
,W
A991
63U
SA
Typ
eof
Equip
men
t:D
ewP
oint
Pot
enti
aMet
er
Mod
elN
um
ber
:W
P4C
Yea
rof
Fir
stM
anu
fact
ure
:20
10
Th
isis
toce
rtif
yth
atth
eD
ewP
oint
Pot
enti
aMet
er,m
anu
fact
ure
dby
ME
TE
RG
rou
p,
Inc.
USA
,a
corp
orat
ion
bas
edin
Pu
llm
an,
Was
h-
ingt
on,
US
Am
eets
orex
ceed
sth
est
and
ard
sfo
rC
Eco
mpli
ance
asp
erth
eC
oun
cil
Dir
ecti
ves
not
edab
ove.
All
inst
rum
ents
are
bu
ilt
at
the
fact
ory
atM
ET
ER
and
per
tin
ent
test
ing
docu
men
tati
onis
free
lyav
aila
ble
for
veri
fica
tion
.
50
WP
4C
1IN
TR
OD
UC
TIO
N
for
whic
hth
esa
me
may
be
emp
loye
d.
Th
eu
seof
this
equ
ipm
ent
con
-st
itu
tes
Bu
yer’
sac
cep
tan
ceof
the
term
sse
tfo
rth
inth
isw
arra
nty
.T
her
ear
eno
un
der
stan
din
gs,
rep
rese
nta
tion
s,or
war
ranti
esof
any
kin
d,
exp
ress
,im
pli
ed,
stat
uto
ryor
other
wis
e(i
ncl
ud
ing,
bu
tw
ith
-ou
tli
mit
atio
n,
the
imp
lied
war
ranti
esof
mer
chan
tab
ilit
yan
dfi
tnes
sfo
ra
part
icula
rp
urp
ose)
,n
otex
pre
ssly
set
fort
hh
erei
n.
3
WP
4C
14A
PP
EN
DIX
B
14
Ap
pen
dix
B
Tem
pera
ture
Corre
ctio
nof
ME
TE
R’s
Verifi
catio
nS
tan
dard
s
Tab
le3:
Water
Activ
ityof
Selected
Salt
Solu
tions
Tem
p.
H2 O
0.5
02.3
36.0
08.5
713.4
117.1
8
( ◦C)
mol/
kg
mol/
kg
mol/
kg
mol/
kg
mol/
kg
mol/
kg
KC
LN
aC
LN
aC
LL
iCl
LiC
lL
iCl
15.0
1.0
00
0.9
84
0.9
23
0.7
61
0.4
92
0.2
38
0.1
40
20.0
1.0
00
0.9
84
0.9
22
0.7
60
0.4
96
0.2
45
0.1
45
25.0
1.0
00
0.9
84
0.9
20
0.7
60
0.5
00
0.2
50
0.1
50
30.0
1.0
00
0.9
84
0.9
20
0.7
60
0.5
04
0.2
55
0.1
55
35.0
1.0
00
0.9
84
0.9
20
0.7
60
0.5
08
0.2
61
0.1
60
40.0
1.0
00
0.9
84
0.9
21
0.7
60
0.5
12
0.2
66
0.1
65
50.0
1.0
00
0.9
84
0.8
94
0.7
40
0.5
17
0.2
75
0.1
72
49
2A
BO
UT
TH
EW
P4C
WP
4C
2A
bou
tth
eW
P4C
2.1
Sp
ecifi
catio
ns
Ran
ge :0
to−
300M
Pa1
Accu
racy
:±0.05
MP
a1
from0
to−
5M
Pa
1%from
−5
to−
300M
Pa
Measu
remen
tT
ime:
∼10
to15
min
utes
form
ostsoil
samp
lesin
precise
mod
e∼
20m
in.
forp
lant
tissue
samp
les<
5m
inutes
infast
mod
e(red
uced
accuracy
)
Tem
peratu
reC
ontrol :
15to
40◦C
(±0.2
◦C)
Op
erating
Environ
men
t:5
to40
◦C(41
to104
◦F)
Sen
sorT
yp
e:A
chilled
-mirror
dew
poin
tsen
soran
dan
Infrared
temp
erature
sensor
Sam
ple
Cu
pC
apacity
:7
mL
recomm
end
ed(15
mL
full)
Dim
ension
s:24.1
x22.9
x8.9
cm(9.5
x9.0
x3.5
in)
Weigh
t :3.2
Kg
(7.1lb
s)
Case
Material:
Pow
der
Pain
tedA
lum
inu
m
Disp
lay:
20x
2alp
han
um
ericL
CD
with
back
lightin
g
Data
Com
mu
nication
:R
S232A
comp
atible,
8-data
bit
AS
CII
cod
e,9600
bau
d,
no
parity,
1stop
bit
Pow
er:110
VA
Cto
220V
AC
,50/60
Hz
Interface
Cab
le:S
tand
ardR
S232
toU
SB
cable
(inclu
ded
)
Com
patib
leS
tand
ards :
AS
TM
D6836-07
Warran
ty:
On
eyear
parts
and
labor
1Th
eW
P4C
(an
dall
vap
or
pressu
rein
strum
ents)
are
limited
by
accu
racy
inth
ew
eten
dof
the
water
poten
tial
ran
ge.
Th
era
nge
of
0to
−5
MP
ah
as
an
accu
racy
of
0.0
5M
Pa.
For
exam
ple,
am
easu
remen
tat−
0.1
MP
ah
as
an
accu
racy
of±
50%
of
the
read
ing
an
d−
1M
Pa
has
an
accu
racy
of±
5%
of
the
read
ing.
Th
eW
P4C
will
not
mea
sure
water
poten
tial
accu
rately
nea
rfield
cap
acity.
4
13A
PP
EN
DIX
AW
P4C
13
Ap
pen
dix
A
13.1
Pre
pari
ng
Salt
Solu
tion
s
Foll
owin
gis
ata
ble
show
ing
the
wat
erp
oten
tial
atgi
ven
con
centr
a-
tion
sof
NaC
lan
dK
Cl
at20
◦ C.
Tab
le2:
Wat
erP
oten
tial
ofN
aCl
and
KC
lin
Meg
apas
cals
(MP
a)
Con
centr
atio
n(M
oles
/kg)
NaC
lK
Cl
0.0
5−
0.23
2−
0.23
20.1
0−
0.45
4−
0.45
20.2
0−
0.90
1−
0.88
80.3
0−
1.34
9−
1.32
60.4
0−
1.79
3−
1.76
00.5
0−
2.24
2−
2.19
00.6
0−
2.69
9−
2.62
20.7
0−
3.15
9−
3.06
10.8
0−
3.61
8−
3.50
10.9
0−
4.08
7−
3.93
11.0
0−
4.55
8−
4.37
2
48
WP
4C
2A
BO
UT
TH
EW
P4C
2.2
WP
4C
an
dW
ate
rP
ote
nti
al
Wat
erp
oten
tial
isa
mea
sure
men
tof
the
ener
gyst
atu
sof
the
wate
rin
asy
stem
.It
ind
icat
esh
owti
ghtl
yw
ater
isb
oun
d,
stru
ctu
rally
orch
emic
ally
,w
ith
ina
sub
stan
ce.
Wat
erp
oten
tial
can
be
com
pu
ted
from
the
vap
orp
ress
ure
ofai
rin
equ
ilib
rium
wit
ha
sam
ple
ina
seal
edm
easu
rem
ent
cham
ber
.F
ora
mor
ed
etai
led
des
crip
tion
ofw
ater
pot
enti
al,
ple
ase
refe
rto
Ch
apte
r9,
titl
ed“T
heo
ry:
Wate
rP
oten
tial”
ofth
ism
anu
al.
2.3
How
the
WP
4C
work
s
Th
eW
P4C
use
sth
ech
ille
dm
irro
rd
ewp
oint
tech
niq
ue
tom
easu
reth
ew
ater
pot
enti
al
ofa
sam
ple
.In
this
typ
eof
inst
rum
ent,
the
sam
ple
iseq
uil
ibra
ted
wit
hth
eh
ead
spac
eof
ase
aled
cham
ber
that
conta
ins
am
irro
ran
da
mea
ns
ofd
etec
tin
gco
nden
sati
onon
the
mir
-ro
r.A
teq
uil
ibri
um
,th
ew
ater
pot
enti
alof
the
air
inth
ech
amb
eris
the
sam
eas
the
wat
erp
oten
tial
ofth
esa
mp
le.
Inth
eW
P4C
,th
em
ir-
ror
tem
per
atu
reis
pre
cise
lyco
ntr
olle
dby
ath
erm
oel
ectr
ic(P
elti
er)
cool
er.
Ap
hot
oel
ectr
icce
lld
etec
tsth
eex
act
poi
nt
at
wh
ich
con
den
-sa
tion
firs
tap
pea
rson
the
mir
ror.
Th
eW
P4C
dir
ects
ab
eam
ofli
ght
onto
the
mir
ror,
whic
hre
flec
tsin
toa
ph
otod
etec
tor.
Th
ep
hot
od
e-te
ctor
sen
ses
the
chan
gein
refl
ecta
nce
wh
enco
nd
ensa
tion
occ
urs
onth
em
irro
r.A
ther
moco
up
leat
tach
edto
the
mir
ror
then
reco
rds
the
tem
per
atu
reat
wh
ich
con
den
sati
onocc
urs
.V
alu
esb
egin
tob
ed
is-
pla
yed
ind
icat
ing
that
init
ial
mea
sure
men
tsar
eb
ein
gta
ken
.W
P4C
then
sign
als
you
by
flas
hin
ga
gree
nL
ED
and
/or
bee
pin
gw
hen
itre
ach
esth
efi
nal
valu
es.
Th
ein
stru
men
tw
ill
dis
pla
yth
efi
nal
wat
erp
oten
tial
and
tem
per
atu
reof
the
sam
ple
.
Inad
dit
ion
toth
ete
chn
iqu
ed
escr
ibed
abov
e,W
P4C
use
san
inte
r-n
alfa
nth
atci
rcu
late
sth
eai
rw
ith
inth
esa
mp
lech
amb
erto
red
uce
tim
eto
equ
ilib
rium
.M
easu
rin
gb
oth
dew
poi
nt
and
sam
ple
surf
ace
tem
per
atu
res
are
sim
ult
aneo
usl
ym
easu
red
,th
isel
imin
ates
the
nee
dfo
rco
mp
lete
ther
mal
equ
ilib
riu
m.
Th
eW
P4C
contr
ols
the
sam
ple
tem
per
atu
reby
mea
ns
ofan
inte
rnal
ther
mo-
elec
tric
al
mod
ule
that
mon
itor
san
dst
abiliz
esth
esa
mp
leb
lock
tem
per
atu
reac
cord
ing
toh
owit
isse
t.
5
WP
4C
12F
UR
TH
ER
RE
AD
ING
•C
lassifi
catio
nof
Expa
nsive
Soils
usin
gth
eW
P4C
Dew
poin
tP
oten
tiaM
eter
47
2A
BO
UT
TH
EW
P4C
WP
4C
2.4
WP
4C
an
dT
em
pera
ture
Large
temp
erature
diff
erences,
betw
eensam
ple
an
db
lock
,w
illca
use
longer
readin
gtim
es,sin
cea
complete
and
accurate
readin
gw
illn
ot
be
mad
eu
ntil
the
diff
erence
betw
eenth
esam
ple
temp
eratu
rean
dth
eblo
cktem
peratu
reis
lessth
an1.0
degree.
To
help
youm
on
itor
the
temp
erature
diff
erence
betw
eenyou
rsam
ple
an
dth
eb
lock
,you
canaccess
aS
amp
leE
qu
ilibration
screenat
the
Main
men
u.
6
12F
UR
TH
ER
RE
AD
ING
WP
4C
12
Fu
rth
er
Read
ing
Refe
ren
ces:
Bry
e,K
.R.,
(200
3).
Lon
g-te
rmeff
ects
ofcu
ltiv
ati
onon
par
ticl
esi
zean
dw
ater
-ret
enti
onch
arac
teri
stic
sd
eter
min
edu
sin
gw
etti
ng
curv
es.
Soil
Sci
ence
Soc
iety
of
Am
eric
a16
8:7
459-
468.
Cam
pb
ell,
E.C
.,G
.S.
Cam
pb
ell,
and
W.K
.B
arlo
w.,
(197
3).
Ad
ewp
oint
hygr
omet
erfo
rw
ater
pot
enti
alm
easu
rem
ent.
Agr
ic.
Met
eor.
12:1
13-1
21.
G.W
.G
ee,
M.D
.C
amp
bel
l,G
.S.
Cam
pb
ell,
and
J.H
.C
am
pb
ell.
,(1
992)
.R
apid
mea
sure
men
tof
low
soil
wat
erp
oten
tials
usi
ng
aw
a-
ter
acti
vit
ym
eter
.S
oil
Sci
ence
Soc
iety
of
Am
eric
a56:
410
68-
1070
.
Pap
end
ick,
R.I
.an
dG
.S.
Cam
pb
ell.
,(1
980)
.T
heo
ryan
dm
easu
re-
men
tof
wat
erp
oten
tial
.in
Wat
erP
oten
tial
Rel
atio
ns
inS
oil
Mic
ro-
bio
logy
.S
oil
Sci
ence
Soc
iety
of
Am
eric
a.
Mad
ison
,W
isco
nsi
n.
pp.
1-22
.
12.1
Ap
pli
cati
on
Note
s
Th
efo
llow
ing
WP
4Cap
pli
cati
onn
otes
are
avai
lab
lefr
omM
ET
ER
by
requ
est
and
from
our
web
site
un
der
the
edu
cati
on
tab
,ch
oose
WP
4C.
•G
ener
ati
ng
aS
oil
Mois
ture
Chara
cter
isti
cw
ith
the
WP
4C
.
•M
easu
rin
gL
eaf
Wate
rP
ote
nti
al
usi
ng
the
WP
4C
.
•F
ield
Port
abi
lity
Inst
ruct
ion
sfo
rth
eW
P4C
.
•W
ate
rP
ote
nti
al:
The
Key
toS
ucc
essf
ul
See
dP
rim
ing.
•S
eed
Lon
gevi
tyin
Sto
rage
isE
nhan
ced
byC
on
troll
ing
Wate
rA
ctiv
ity.
46
WP
4C
3G
ET
TIN
GS
TA
RT
ED
3G
ett
ing
Sta
rted
3.1
Com
pon
ents
of
you
rW
P4C
You
rW
P4C
shou
ldh
ave
ship
ped
wit
hth
efo
llow
ing
item
s.
•W
P4C
Mai
nU
nit
•Q
uic
kst
art
Gu
ide
•C
erti
fica
teof
Cal
ibra
tion
•P
ower
Cor
d•
RS
-232
toU
SB
Cab
le•
25P
last
icS
amp
leC
up
san
dL
ids
•10
Sta
inle
ssS
teel
Sam
ple
Cu
ps
•O
per
ator
’sM
anu
al•
12V
ials
of0.
50m
ol/k
gK
Cl
•C
lean
ing
Kit
3.2
Ch
oosi
ng
aL
oca
tion
To
ensu
reth
atyo
ur
WP
4Cop
erat
esco
rrec
tly
and
con
sist
entl
y,p
lace
iton
ale
vel
surf
ace.
Th
isre
du
ces
the
chan
ceth
at
sam
ple
mate
rial
wil
lsp
ill
and
conta
min
ate
the
insi
de
ofth
ein
stru
men
t.T
op
rote
ctth
ein
tern
alel
ectr
ical
com
pon
ents
,an
dto
avoi
din
accu
rate
read
ings
,p
lace
you
rW
P4C
ina
loca
tion
wh
ere
the
tem
per
atu
rere
mai
ns
fair
lyst
able
.T
his
loca
tion
shou
ldb
ew
ell
away
from
air
con
dit
ion
eran
dh
eate
rve
nts
,op
enw
ind
ows,
outs
ide
door
s,re
frig
erat
or
exh
aust
s,or
oth
erit
ems
that
may
cau
sera
pid
tem
per
atu
refl
uct
uat
ion
.
7
WP
4C
11T
RO
UB
LE
SH
OO
TIN
G
Th
eP
erforman
ceE
valuation
screengives
youfou
rvalu
es.T
he
top
leftvalu
eis
the
value
the
therm
ocou
ple
isread
ing.
Itis
basica
llyth
ed
ifferen
cein
temp
erature
betw
eenth
eb
lock
and
the
mirror.
Ifth
isis
zero,th
ereis
someth
ing
wron
gw
ithth
eth
ermocou
ple.
Th
etop
right
valu
eis
the
value
readby
the
therm
opile,
wh
ichis
the
temp
er-atu
red
ifferen
ceb
etween
the
blo
ckan
dw
hat
it“sees”
below
it(th
esam
ple,
wh
enrea
din
g).T
his
value
isvariab
le,b
ut
shou
ldn
everb
ezero.
Th
eb
ottomleft
value
isth
eb
lock
temp
erature.
This
valu
esh
ould
be
aroun
dam
bien
ttem
peratu
re.
Th
eb
ottomrig
ht
value
isth
em
irrorrefl
ectance
voltage,in
un
itsof
volts.T
his
value
shou
ldn
ormally
be
aroun
d0.5
orab
ove,b
ut
ifit
drop
sb
elow0.3,
there
issom
ethin
gw
rong.
You
cann
otch
ange
anyth
ing
inth
isscreen
,b
ut
itw
illin
dicate
com-
pon
ent
perfo
rman
ce.If
youn
oticeth
atan
yof
these
values
are
not
wh
atth
eysh
ould
be,
contact
ME
TE
RS
up
port
forfu
rther
instru
c-tion
.P
ressth
eb
utton
nex
tto
Exit
toget
back
toth
em
ainm
enu
.
45
3G
ET
TIN
GS
TA
RT
ED
WP
4C
3.3
Featu
res
Figu
re1:
Fron
tV
iewof
WP
4C
Figu
re2:
Back
View
ofW
P4C
3.4
Pre
parin
gth
eW
P4C
for
Op
era
tion
After
fin
din
ga
good
location
foryou
rW
P4C
,p
lug
the
pow
ercord
into
the
back
of
the
un
it.B
eforetu
rnin
git
on,
pu
llop
enth
esa
mp
led
rawer
(turn
the
kn
obto
the
OP
EN
/LO
AD
position
).Y
ouu
sually
place
anem
pty
disp
osable
samp
lecu
pu
psid
e-dow
nin
the
draw
erto
8
11T
RO
UB
LE
SH
OO
TIN
GW
P4C
Ifth
eb
lock
isp
rop
erly
plu
gged
into
the
mot
her
board
an
dth
ism
essa
geap
pea
rs,
itis
like
lyth
aton
eor
more
ofth
eco
mp
o-
nen
tshav
efa
iled
onth
eb
lock
circ
uit
boa
rd.
7.
PR
OB
LE
M:
Th
e“S
etT
”op
tion
does
not
app
ear
anym
ore
inth
eW
P4C
Syst
emC
onfi
gura
tion
men
u.
SO
LU
TIO
N:
Th
ete
mp
erat
ure
contr
olm
od
ule
insi
de
the
WP
4Cis
bro
ken
orn
ot
fun
ctio
nin
gco
rrec
tly.
Wh
enth
ein
stru
men
tse
nse
sth
at
ther
eis
ap
rob
lem
wit
hth
ete
mp
erat
ure
contr
olm
od
ule
,it
rem
oves
that
fun
c-ti
onas
anop
tion
toth
eu
ser
asa
pre
cau
tion
.C
onta
ctM
ET
ER
for
serv
ice
info
rmat
ion
.
11.2
Sen
sor
Perf
orm
an
ceS
creen
If,
afte
rcl
ean
ing
you
rin
stru
men
tan
dre
vie
win
gth
etr
oub
lesh
oot
ing
item
s,you
hav
ere
ason
tob
elie
veth
aton
eof
the
com
pon
ents
ofyo
ur
WP
4Cm
ayb
eca
usi
ng
mea
sure
men
ter
ror,
you
can
acce
ssa
scre
enth
atw
ill
dis
pla
yva
lues
for
com
pon
ent
per
form
ance
.A
cces
sth
issc
reen
by
hol
din
gd
own
the
low
erri
ght
bu
tton
wh
ile
turn
ing
onth
ein
stru
men
t.A
fter
itin
itia
lize
s,it
wil
lb
eep
an
dco
me
toth
eP
erfo
rman
ceE
valu
atio
nsc
reen
.
44
WP
4C
3G
ET
TIN
GS
TA
RT
ED
pro
tect
itd
uri
ng
ship
men
t.R
emov
eth
issa
mple
cup
and
turn
the
inst
rum
ent
on.
Th
eO
N/O
FF
swit
chis
loca
ted
onth
elo
wer
righ
tco
rner
ofth
eW
P4C
bac
kp
anel
.T
he
mod
elan
dth
enth
em
ain
men
uw
ill
app
ear
onth
eL
CD
.
Th
en:
Th
isis
the
Mai
nm
enu
,d
isp
layin
gth
ew
ater
pote
nti
alin
bot
hM
ega-
Pas
cals
(MP
a)an
dp
F,an
dth
esa
mp
lete
mp
erat
ure
in◦ C
.In
ord
erto
pro
vid
eth
em
ost
accu
rate
read
ings
,W
P4C
shou
ldid
eall
yb
eall
owed
aw
arm
-up
per
iod
of15
to30
min
ute
saf
ter
turn
ing
iton
.W
hen
you
inse
rta
sam
ple
into
the
cham
ber
dra
wer
and
turn
the
dra
wer
kn
obto
the
RE
AD
pos
itio
n,
the
inst
rum
ent
wil
lb
egin
the
read
cycl
eto
mea
sure
the
wat
erp
oten
tial
ofyo
ur
sam
ple
.
3.5
Port
ab
ilit
y
On
occ
asio
nyo
um
ayw
ant
tota
kew
ater
pot
enti
alm
easu
rem
ents
inth
efi
eld
wher
eit
isn
otfe
asib
leto
take
sam
ple
san
dre
turn
toth
ela
b.
Th
efo
llow
ing
isa
pro
ced
ure
for
pow
erin
gyo
ur
WP
4Cu
sin
gyo
ur
veh
icle
asa
pow
erso
urc
eat
site
sw
her
eA
Cp
ower
isn
otre
adil
yav
aila
ble
.
1.P
urc
has
ea
por
tab
lep
ower
inve
rter
that
plu
gsin
toth
e12
Vou
tpu
t(c
igar
ette
ligh
ter)
ofyo
ur
veh
icle
.T
he
inver
ter
shou
ldh
ave
aco
nti
nu
ous
outp
ut
ofat
leas
t14
0W
atts
.
9
WP
4C
11T
RO
UB
LE
SH
OO
TIN
G
5.
PR
OB
LE
M:
Asm
alltrian
gleap
pears
inth
eu
pp
errigh
tcorn
erafter
readin
g:
SO
LU
TIO
N:
Th
em
irrorn
eeds
tob
eclean
ed,
along
with
the
restof
the
sam
ple
cham
ber,
until
itd
isapp
ears.T
his
triangle
isa
mirror
perform
an
cein
dicator.
Wh
enth
eW
P4C
senses
that
the
mirro
rp
erform
ance
has
drop
ped
toun
acceptab
lelevels,
itw
illd
isplay
the
triangu
lar
warn
ing
signafter
measu
ring
the
samp
le.W
hen
this
app
ears,you
shou
ldstop
samp
ling
and
cleanth
ech
amb
er.If
the
triangle
isstill
onth
escreen
afterclean
ing,
the
mirror
ism
ostlikely
stilld
irtyan
dyo
uw
illn
eedto
cleanit
until
the
triangle
disap
pears.
6.
PR
OB
LE
M:
“Blo
ckfailu
re”m
essageap
pears
onscreen
.
SO
LU
TIO
N:
•T
he
blo
ckis
not
plu
ggedin
toth
em
otherb
oard.
Op
enth
ecase
and
check
tom
ake
sure
that
the
small
ribb
on
cable
that
conn
ectsth
eb
lock
toth
em
otherb
oardis
snap
ped
an
dlo
cked
inp
lace.
•O
ne
orm
orecom
pon
ents
has
failedon
the
blo
ckcircu
itb
oard.
43
3G
ET
TIN
GS
TA
RT
ED
WP
4C
2.P
laceth
eW
P4C
ona
levelsu
rface.C
aresh
ould
be
taken
tom
inim
izetem
peratu
regrad
ients
that
may
affect
the
instru
men
tw
hile
inth
efi
eld.
AS
tyrofoam
box
,for
exam
ple,
will
help
min
imize
temp
erature
effects.
3.P
lug
the
12-voltin
verterto
the
12-volt
outp
ut
ofth
eveh
icle,or
directly
toth
eb
atteryitself.
4.P
lug
the
WP
4Cto
the
inverter,
and
turn
iton
.W
hen
the
instru
men
tis
on,
itd
raws
up
to1
amp.
Ch
eckth
eratin
gof
your
battery
ifyou
wan
tto
kn
owh
owlon
git
will
pow
erth
ein
strum
ent
(forex
amp
le,if
your
battery
israted
for60
am
ph
ours,
itw
illw
orkfor
60h
ours
wh
enth
eveh
icleis
not
run
nin
g.
5.A
llowth
ein
strum
ent
tow
armu
pfor
15to
30
min
utes
asyou
wou
ldin
the
lab.
Ch
eckth
ecalib
rationof
the
instru
men
tb
efore
pro
ceedin
gw
ithread
ing.
10
11T
RO
UB
LE
SH
OO
TIN
GW
P4C
fan
bla
de.
Th
isis
esp
ecia
lly
like
lyif
you
hav
eju
stcl
ean
edth
ech
amb
er.
Ifyo
usu
spec
tth
ism
ayh
ave
hap
pen
ed,
conta
ctM
ET
ER
for
det
ails
onre
pla
cem
ent.
3.
PR
OB
LE
M:
Wat
erp
oten
tial
read
ings
onK
Cl
stan
dar
ds
are
too
hig
hor
low
and
aca
lib
rati
onad
just
men
tca
nn
otb
em
ade
any
hig
her
orlo
wer
.
SO
LU
TIO
NS
:
•T
he
ther
mop
ile
inyo
ur
cham
ber
,w
hic
hm
easu
res
sam
ple
tem
-p
erat
ure
,m
ayh
ave
bec
ome
conta
min
ated
.R
efer
toC
hap
ter
10fo
rd
irec
tion
son
clea
nin
g.
•If
you
are
not
usi
ng
ME
TE
R’s
KC
lve
rifi
cati
on
stan
dar
ds,
hig
hre
adin
gsm
ayin
dic
ate
that
the
salt
solu
tion
you
are
usi
ng
isn
otin
equ
ilib
riu
m.
4.
PR
OB
LE
M:
Mes
sage
onsc
reen
dis
pla
ys
the
foll
owin
g(ex
amp
le):
SO
LU
TIO
N:
•T
he
sam
ple
isto
od
ryfo
rth
ein
stru
men
tto
read
acc
ura
tely
.If
you
rsa
mp
leh
asa
wat
erp
oten
tial
that
isab
ove
the
det
ecti
on
lim
its
ofth
ein
stru
men
t,th
ism
essa
gew
illco
me
up
.E
ssen
tial
ly,
itm
ean
sth
atth
ere
isn
oten
ough
sam
ple
moi
stu
reto
con
den
seon
the
mir
ror
and
pro
vid
ea
read
ing.
•T
he
mir
ror
may
be
dir
ty.
Try
clea
nin
gth
em
irro
ran
dch
amb
eran
dm
easu
rin
gth
esa
mp
leag
ain
.
42
WP
4C
4T
HE
ME
NU
S
4T
he
Menu
s
4.1
Th
eM
ain
Menu
Eve
ryti
me
you
turn
onyo
ur
WP
4C,
itw
ill
open
toth
issc
reen
.If
this
scre
endoes
not
app
ear,
refe
rto
Ch
apte
r12
for
trou
ble
shoot
ing
inst
ruct
ion
s.T
he
wat
erp
oten
tial
and
sam
ple
tem
per
atu
red
ispla
ys
onth
esc
reen
.O
nea
chsi
de
ofth
eL
CD
ther
ear
eb
utt
ons.
Eac
hb
utt
onp
erfo
rms
ad
iffer
ent
fun
ctio
nd
epen
din
gon
whic
hm
od
eyo
uw
ant.
Fig
ure
3p
rovid
esa
des
crip
tion
ofth
em
od
esan
dop
tion
syou
may
use
and
the
bu
tton
sth
atse
tth
em.
Fig
ure
3:M
ain
Men
uS
cree
n
4.1
.1C
han
gin
gL
an
gu
ages
Th
eW
P4C
com
esto
you
wit
hE
ngl
ish
asth
ed
efau
lton
-scr
een
use
rla
ngu
age
.If
you
pre
fer
not
tou
seE
ngl
ish
,yo
uca
nch
ange
itto
one
ofa
vari
ety
ofot
her
lan
guag
es:
Ger
man
,F
ren
ch,
Sp
anis
h,
Ital
ian
,S
wed
ish
,D
anis
h,
Nor
weg
ian
,C
zech
,P
ortu
gues
e,Jap
anes
e,P
olis
hor
11
WP
4C
11T
RO
UB
LE
SH
OO
TIN
G
•C
heck
tom
akesu
reyou
rp
ower
cordis
securely
attached
toth
eb
ackof
the
instru
men
tan
dth
ep
ower
outlet.
•A
pow
ersu
rem
ayh
avecau
seda
fuse
tob
low.
Follow
steps
1th
rough
5to
chan
geth
efu
ses.
1.U
np
lug
the
pow
ercord
fromth
ew
allan
dth
ein
strum
ent.
2.L
ocate
the
pan
elw
here
the
pow
ercord
plu
gsin
.T
he
fuse
box
ison
the
right
side
ofth
atp
anel.
Press
inon
the
releasetab
and
pu
llth
efu
se-hold
erou
t.
3.P
ull
the
broken
fuse(s)
out
and
replace
with
a2.0
Am
p250
Vfu
se.C
aution
:D
on
otuse
any
other
kin
dof
fuse
oryou
will
riskd
amage
toyou
rin
strum
ent
and
voidyou
rw
arran
ty.
4.R
epla
ceth
efu
se-hold
eran
dp
ush
itin
toth
efu
se-well
until
the
releasetab
snap
sin
top
lace.
5.R
econn
ectth
ep
ower
cordan
dtu
rnyou
rin
strum
ent
on.
Ifth
efu
seb
lows
again,
afailed
comp
onen
tm
ayb
ecau
s-in
gth
ep
roblem
.C
ontact
ME
TE
Rto
make
arrangem
ents
for
repairs
ifyou
rp
roblem
persists.
2.
PR
OB
LE
M:
Read
ings
areslow
orin
consisten
t.
SO
LU
TIO
N:
•T
he
samp
lech
amb
erm
ayb
ed
irty.R
eferto
Ch
apter
10of
the
manu
al
ford
irections
onclean
ing
the
samp
lech
amb
er.
•S
ome
samp
lesab
sorbor
desorb
moistu
revery
slowly,
cau
sing
measu
remen
tsto
takelon
gerth
anu
sual,
and
noth
ing
canb
ed
one
tosp
eedu
pth
ep
rocess.
Refer
toC
hap
ter6
forfu
rther
exp
lanation
.
•T
he
fan
blad
ein
side
the
blo
ckch
amb
erm
ayb
eb
roken.
Ifeven
the
KC
lstan
dard
takesa
long
time
toread
,an
dth
esam
ple
cham
ber
isclean
,you
may
hav
ea
broken
orb
ent
cham
ber
41
4T
HE
ME
NU
SW
P4C
Fin
nish
.C
han
gelan
guages
by
pressin
gth
eu
pp
errig
ht
bu
tton
of
the
instru
men
tw
hile
itis
not
readin
ga
samp
le.Y
ou
will
seeth
eL
angu
agescreen
with
defau
ltE
nglish
.
Press
the
up
per
right
keyagain
,an
dth
en
ext
langu
ageop
tion
(Ger-
man
)w
illap
pear.
Each
time
youp
ressth
erigh
tb
utton
,th
ed
isplay
will
scroll
toth
en
ext
langu
ageop
tion.
Select
the
langu
ageyou
prefer
and
press
the
lower
leftb
utton
toex
it.
4.1
.2R
ead
ing
Mod
es
Pre
cise
Mod
e
Wh
enyou
first
turn
onth
eW
P4C
,it
will
be
inp
recisem
od
e.T
he
WP
4Crep
eatssam
ple
measu
remen
tsu
ntil
successive
readin
gs
agree
with
ina
preset
tolerance
(0.03M
Pa
forΨ>
−40
MP
a;oth
erwise
0.3M
Pa).
Th
eW
P4C
alway
sstarts
inp
recisem
od
e.T
otog
gleb
etween
the
precise,
contin
uou
san
dfast
mod
es,p
ressth
etop
leftb
utton
.T
he
disp
layw
illsh
owa
small
p,
cor
fto
the
leftof
the
water
poten
tialread
ings.(F
igure
4)
12
11T
RO
UB
LE
SH
OO
TIN
GW
P4C
11
Tro
ub
lesh
ooti
ng
WP
4Cis
ah
igh
per
form
ance
inst
rum
ent,
des
ign
edto
hav
elo
wm
ain
-te
nan
cean
dfe
wp
rob
lem
sif
use
dw
ith
care
.U
nfo
rtu
nate
ly,
som
e-ti
mes
even
the
bes
top
erat
ors
usi
ng
the
bes
tin
stru
men
tsen
cou
nte
rte
chn
ical
diffi
cult
ies.
Her
eis
ali
stof
som
ep
rob
lem
sth
atm
ayoc-
cur.
Ifyo
uh
ave
enco
unte
red
ap
rob
lem
that
isn
otad
dre
ssed
her
e,or
ifth
ese
rem
edie
sst
ill
do
not
reso
lve
you
rp
rob
lem
,co
nta
ctM
E-
TE
Rat
509-
332-
5600
(for
thos
eou
tsid
eth
eU
S).
Ifp
urc
has
edfr
oma
dis
trib
uto
r,p
leas
eco
nta
ctth
ed
istr
ibu
tor
for
assi
stan
cefi
rst.
11.1
Pro
ble
ms
an
dS
olu
tion
s
Th
efo
llow
ing
tab
leis
ab
rief
guid
eto
hel
pyo
uqu
ickly
defi
ne
so-
luti
ons
toyo
ur
pro
ble
ms.
For
mor
ed
etai
led
des
crip
tion
sof
thes
ep
rob
lem
san
dth
eir
solu
tion
s,se
eth
eex
pla
nat
ion
sb
elow
the
tab
le.
Tab
le1:
Tro
ub
lesh
oot
ing
Qu
ick
Gu
ide
Ifth
isp
rob
lem
occu
rs:
Refe
rto
:
WP
4Cd
oes
not
turn
onP
rob
lem
#1
Lon
gR
ead
Tim
eP
rob
lem
#2
Rea
din
gson
KC
lst
and
ard
sar
eto
oh
igh
/low
toad
just
Pro
ble
m#
3
Rea
din
g<
−30
1.8
MP
aP
rob
lem
#4
Tri
angl
eap
pea
rsin
up
per
righ
tco
rner
Pro
ble
m#
5“B
lock
Fai
lure
”ap
pea
rson
scre
enaf
ter
turn
ing
onW
P4C
Pro
ble
m#
6
“Set
T”
opti
onno
lon
ger
app
ears
onS
yst
emC
on-
figu
rati
onm
enu
Pro
ble
m#
7
1.
PR
OB
LE
MW
P4C
does
not
turn
on.
SO
LU
TIO
NS
:
40
WP
4C
4T
HE
ME
NU
S
Fig
ure
4:M
ain
Men
uw
ith
Con
tinu
ous
Mod
eE
nab
led
Pre
cise
mod
een
sure
sa
pre
cise
wat
erp
oten
tial
valu
eby
rep
eati
ng
mea
sure
men
tson
asa
mp
le.
Typ
ical
read
tim
esar
ew
ith
in10
to15
min
ute
s.T
he
gree
nL
ED
bli
nks
unti
lyou
turn
the
dra
wer
kn
owto
the
OP
EN
/LO
AD
pos
itio
n.
Conti
nu
ou
sM
od
e
Con
tinu
ous
mod
em
easu
res
the
wat
erp
oten
tial
ofyo
ur
sam
ple
con
-ti
nu
ou
sly
unti
lyo
utu
rnth
ed
raw
erkn
obto
the
OP
EN
/LO
AD
po-
siti
on.
Th
isca
nb
eu
sefu
lin
doi
ng
lon
gte
rmm
onit
orin
gof
sam
ple
sth
atta
kean
esp
ecia
lly
lon
gti
me
toco
me
tova
por
equ
ilib
rium
,su
chas
pla
nt
sam
ple
san
dm
oist
soil
sam
ple
sw
ith
wate
rp
ote
nti
al>
−0.
5M
Pa.
Inth
ism
od
eth
eW
P4C
wil
lm
easu
reth
esa
mple
,st
opto
dis
-p
lay
the
wat
erp
oten
tial
and
sam
ple
tem
per
atu
re,th
enb
egin
anot
her
read
cycl
e.B
etw
een
sam
ple
s,it
wil
lsi
gnal
you
wit
hth
egr
een
LE
Dfl
ash
,ac
com
pan
ied
by
the
bee
per
,if
enab
led
.S
ome
fin
dit
hel
pfu
lto
con
nec
tth
eir
WP
4Cto
aco
mp
ute
rw
hil
ein
conti
nu
ous
mod
ein
ord
erto
log
and
stor
ed
ata
over
tim
e.F
orin
stru
ctio
ns
onh
owto
do
this
,se
eC
hap
ter
8.
Fast
Mod
e
Infa
stm
od
e,th
esa
mple
ism
easu
red
only
once
.R
ead
tim
eis
typ
-ic
ally
3to
5m
inu
tes.
Rea
din
gsar
ele
ssp
reci
se,
par
ticu
larl
yin
the
wet
ran
ge.
How
ever
,fa
stm
od
eis
reco
mm
end
edfo
rd
ryso
ilsa
mp
les
wit
hw
ater
pote
nti
al<
−40
MP
a. 13
WP
4C
10R
EP
AIR
INS
TR
UC
TIO
NS
3.D
on
otsh
ipyou
rW
P4C
tou
sw
ithth
ep
ower
cord
;w
eh
avep
lenty
here
touse
with
your
instru
men
t,an
dit
may
dam
age
the
instru
men
tin
ship
men
t.
4.P
leaserev
iewth
eR
MA
forman
dverify
the
ship
toan
db
illto
info
rmation
,con
tactnam
e,an
dp
roblem
descrip
tion.
Ifan
y-
thin
gis
incorrect,
please
contact
aM
ET
ER
represen
tative.
5.T
ape
the
box
inb
othd
irections
soit
will
not
brea
kop
enin
ship
men
t.
6.In
clud
eth
eR
MA
nu
mb
erin
the
attention
line
onth
esh
ipp
ing
label.
Sh
ipto
:M
ET
ER
Gro
up
,In
c.A
TT
N:
RM
A(in
sertyou
rR
MA
#)
2365N
EH
opkin
sC
ourt
Pu
llman
,W
A99163
10.2
Rep
air
Costs
Man
ufactu
rersd
efectsan
din
strum
ents
with
inth
eon
e-yearw
arranty
will
be
repaired
atn
ocost.
For
non
-warran
tyrep
airs(in
clud
ing
cleanin
gsfor
instru
men
tsin
their
warran
typ
eriod
),costs
forp
arts,
labor,
and
ship
pin
gw
illb
eb
illedto
you.
We
have
am
inim
um
repair
charg
e,an
dan
extra
feew
illb
ech
argedfor
rush
work
.M
ET
ER
will
prov
ide
anestim
atedrep
aircost,
ifreq
uested
.
10.3
Loan
er
Serv
ice
ME
TE
Rh
asloan
erin
strum
ents
tokeep
youm
easurin
gw
ateractiv
ityw
hile
you
rin
strum
ent
isb
eing
serviced
.If
your
WP
4Cis
stillu
nd
ercalib
rationw
arranty
oryou
have
aserv
iceplan
with
you
rin
strum
ent,
there
isn
och
argefor
the
loaner
service.
39
4T
HE
ME
NU
SW
P4C
4.2
Syste
mC
on
figu
ratio
n
Ifyou
press
the
bottom
leftb
utton
wh
ilein
the
Main
men
u,
itw
illb
ring
youto
the
System
Con
figu
rationm
enu
.T
his
men
uallow
syou
tom
ake
min
orsy
stemch
anges.(F
igure
5an
d6)
Figu
re5:
Main
Men
uB
utton
s
You
canch
ange
how
the
beep
ersign
alsafter
eachread
ing
and
enter
the
calibration
men
uas
well.
Figu
re6:
System
Con
figu
rationM
enu
Ch
an
gin
gth
eB
eep
er
Wh
enyou
areread
ing,
the
WP
4Ch
astw
ow
ays
ofn
otifyin
gyo
uw
hen
itcom
pletes
the
water
poten
tialread
ing
foryou
rsa
mp
le.It
will
notify
you
with
the
beep
erh
eb
eeper
and
afl
ashin
ggreen
LE
D,
14
10R
EP
AIR
INS
TR
UC
TIO
NS
WP
4C
10
Rep
air
Inst
ruct
ion
s
Ifyo
ur
WP
4Cev
ern
eed
sto
be
sent
info
rse
rvic
eor
rep
air,
call
ME
-T
ER
at50
9-33
2-56
00or
fax
us
at50
9-33
2-51
58.
We
wil
las
kyo
ufo
ryo
ur
add
ress
,p
hon
enu
mb
er,
and
seri
alnu
mb
er.
For
non
-war
ranty
rep
airs
,w
ew
ill
also
ask
for
apay
men
tm
eth
od
(su
chas
ap
urc
has
eor
der
orcr
edit
card
nu
mb
er),
are
pai
rb
ud
get,
and
bil
lin
gad
dre
ss.
Note
:If
you
pu
rchase
dyo
ur
WP
4C
from
on
eof
ou
rin
tern
ati
on
al
dis
trib
uto
rs,
ple
ase
con
tact
them
befo
reco
nta
ctin
gM
ET
ER
.T
hey
may
beabl
eto
pro
vide
you
wit
hlo
cal
serv
ice
an
dhel
pyo
ure
med
yth
epro
blem
.
10.1
Sh
ipp
ing
Dir
ect
ion
s
Wh
enyo
ush
ipyo
ur
inst
rum
ent
bac
kto
us,
ple
ase
incl
ude
wit
hit
ad
ocu
men
tw
ith
the
com
ple
tesh
ipp
ing
add
ress
,n
am
ean
dd
epart
men
tof
the
per
son
resp
onsi
ble
for
the
inst
rum
ent,
and
(mos
tim
por
tantl
y)
ad
escr
ipti
onof
the
pro
ble
m.
Th
isin
form
atio
nw
ill
bet
ter
hel
pou
rte
chn
icia
ns
and
our
ship
pin
gd
epar
tmen
tto
exp
edit
ere
pair
onyo
ur
inst
rum
ent
and
ship
itb
ack
toyo
uin
good
tim
e.
All
WP
4Cs
retu
rnin
gto
ME
TE
Rfo
rse
rvic
ing
mu
stb
eac
com
pa-
nie
dw
ith
aR
etu
rnM
ater
ial
Au
thor
izat
ion
(RM
A)
form
.P
rior
tosh
ipp
ing
the
inst
rum
ent,
ple
ase
conta
cta
ME
TE
Rcu
stom
ersu
pp
ort
rep
rese
nta
tive
toob
tain
anR
MA
.
Foll
owst
eps
1th
rou
gh6
tosu
cces
sfu
lly
and
safe
lysh
ipyo
ur
in-
stru
men
tbac
kto
us.
1.If
pos
sib
le,
ship
you
rW
P4C
bac
kin
its
orig
inal
card
boa
rdb
oxw
ith
foam
inse
rts.
Ifth
isis
not
pos
sib
le,
use
ab
oxth
ath
asat
least
four
inch
esof
spac
eb
etw
een
you
rin
stru
men
tan
dea
chw
all
ofth
eb
ox.
Ifyo
uar
en
otu
sin
gth
efo
amin
sert
s,p
ack
the
box
moder
atel
yti
ght
wit
hp
ackin
gm
ater
ial,
like
styro
foam
pea
nu
ts
2.P
ut
you
rin
stru
men
tin
ap
last
icb
agto
avoi
dd
isfi
gu
rin
gm
arks
from
the
pac
kagi
ng.
38
WP
4C
4T
HE
ME
NU
S
loca
ted
on
the
left
fron
tco
rner
ofth
eW
P4C
case
.In
fast
and
pre
-ci
sere
adin
gm
od
es,th
eL
ED
wil
lfl
ash
once
wh
ena
sam
ple
isst
arte
d.
Wh
enit
isfi
nis
hed
the
LE
Dw
ill
flas
hco
nti
nu
ousl
yu
nti
lth
ekn
obis
mov
edto
the
OP
EN
/LO
AD
pos
itio
n(i
fn
otop
erat
ing
inco
nti
nu
ous
mod
e).
You
can
not
turn
offor
chan
geth
eL
ED
flash
ing
fun
ctio
ns.
Th
ree
diff
eren
tic
ons
rep
rese
nt
the
thre
eb
eep
erop
tion
s.(F
igu
re7)
Fig
ure
7:D
efin
itio
nof
Bee
per
Icon
s
you
can
turn
the
bee
per
offco
mp
lete
ly,
set
itto
bee
pm
omen
tari
ly(f
ou
rti
mes
)w
hen
the
sam
ple
isfin
ish
edan
dth
enst
op,
orto
bee
pco
nti
nu
ousl
yu
nti
lyo
utu
rnth
ekn
obto
the
OP
EN
/LO
AD
pos
itio
n.
Aft
eryo
uh
ave
adju
sted
the
bee
per
sett
ing,
itw
illre
mai
nas
you
hav
ese
tit
unti
lyo
uch
an
geit
agai
n,
and
wil
ln
otb
eaff
ecte
dby
turn
ing
the
inst
rum
ent
onor
off.
EX
IT
You
may
pre
ssth
eE
xit
bu
tton
(th
elo
wer
left
bu
tton
)to
exit
bac
kto
the
mai
nm
enu
atan
yti
me.
Ad
just
ing
Cali
bra
tion
Wh
enyo
un
eed
toad
just
cali
bra
tion
,p
ress
the
up
per
right
bu
tton
inth
eS
yst
emC
onfi
gura
tion
men
u,
and
you
wil
lb
eb
rou
ght
toth
eC
alib
rati
on
men
u.
For
mor
ed
etai
lson
cali
bra
tion
and
how
tove
rify
it,
ple
ase
refe
rto
the
Cal
ibra
tion
and
Ver
ifica
tion
chap
ter.
Sett
ing
the
Tem
pera
ture
15
WP
4C
9C
LE
AN
ING
AN
DM
AIN
TE
NA
NC
E
9.3
Ch
eck
ing
Calib
ratio
n
After
youh
aveclean
edth
ech
amb
eran
doth
erparts
ofyou
rW
P4C
,it
isim
portan
tto
check
the
instru
men
tp
erforman
cein
order
tocorrect
forany
calibratio
nch
ange
that
may
have
occu
rredd
urin
gclean
ing
pro
cedu
res.
Ch
eckth
ecalib
rationof
your
instru
men
tby
mea
surin
gth
ew
aterp
otential
ofth
eK
Cl
stand
ard.
Ifa
chan
geh
asoccu
rred,
referto
chap
ter5
ford
irections
onh
owto
recalibrate.
If,after
adju
sting
calibration
your
instru
men
tis
stilln
otread
ing
samp
lesco
rrectly,con
tactM
ET
ER
fortech
nical
sup
port.
37
4T
HE
ME
NU
SW
P4C
Th
eW
P4C
givesyou
the
ability
tom
anu
allyset
your
instru
men
tsam
ple
cham
ber
temp
erature.
To
setyou
rin
strum
ent
samp
lech
am-
ber
temp
erature,
press
the
lower
right
bu
ttonn
ext
toth
e“set
T”
inth
eS
ystem
Con
gu
rationm
enu
.T
he
followin
gscreen
will
app
ear:
Ad
justin
gth
eS
etp
oin
tT
em
pera
ture
Use
the
bu
ttons
nex
tto
+an
d−
toad
just
the
target
setpoin
ttem
-p
erature
(disp
layedin
the
lower
right
corner).
Ifyou
press
either
bu
ttonit
adju
stsin
increm
ents
of0.1
◦C.
Note:
Hold
ing
dow
nth
ebu
tton
will
rapid
lyin
cremen
tth
eva
lue.
Th
etarget
setpoin
ttem
peratu
rerou
ghly
correspon
ds
toth
etem
-p
erature
atw
hich
youw
ishth
esam
ple
toread
.A
dju
stth
esetp
oint
toth
etem
peratu
reth
atyou
wan
t,th
enb
eginm
easurem
ents
tosee
how
closeyou
rW
P4C
comes
toyou
rd
esiredtem
peratu
re(th
isw
ork
sb
estby
pu
tting
the
WP
4Cin
contin
uou
sm
od
e).A
ftersevera
lsa
m-
ples,
itsh
ould
show
consisten
ttem
peratu
reread
ings.
At
this
poin
t,m
akean
yn
eeded
adju
stmen
tto
the
setpoin
tin
dex
nu
mb
erto
reachyou
rd
esiredtem
peratu
re.Y
ouw
illb
eab
leto
adju
stth
ein
dex
nu
m-
ber
betw
een15
and
40◦C
.If
youp
ressth
e−b
utton
afteryou
reach15
◦C,
itw
illd
isable
the
temp
erature
control
fun
ctionu
ntil
youraise
the
ind
exnu
mb
eragain
.W
hen
the
temp
erature
contro
lis
disa
bled
the
disp
layw
illsh
ow‘off
’in
place
ofth
etem
peratu
resettin
g.
Imp
orta
nt
tips
with
the
WP
4C
•B
eforeread
ing,
wait
forap
prox
imately
30m
inu
testo
letth
ech
amb
ertem
peratu
restab
ilizeafter
turn
ing
iton
.
16
9C
LE
AN
ING
AN
DM
AIN
TE
NA
NC
EW
P4C
Cle
an
itin
the
sam
em
ann
eras
des
crib
edab
ove
for
the
mir
ror.
4.C
lean
ing
the
Th
erm
opil
e
(a)
Wra
pa
new
Kim
wip
ear
oun
dth
een
dof
the
thin
pla
s-ti
cro
d(s
pat
ula
)an
dm
oist
enit
wit
his
opro
pyl
alc
ohol
orcl
ean
ing
solu
tion
.
(b)
WA
SH
–Sw
ipe
the
moi
sten
edK
imw
ipe
acro
ssth
erm
op
ile.
(Asi
ngl
esw
ipe
isu
sual
lysu
ffici
ent
tore
mov
eco
nta
mi-
nan
ts.)
(c)
RIN
SE
–Rep
eat
step
sa-
bu
sing
new
Kim
wip
esm
ois
ten
edw
ith
dei
oniz
edw
ater
inst
ead
ofcl
ean
ing
solu
tion
.
(d)
DR
Y–R
epea
tst
eps
a-b
bu
tu
sea
new
,d
ryK
imw
ipe
toh
elp
rem
ove
any
moi
stu
rere
mai
nin
gfr
omth
ecl
ean
ing.
(e)
Vis
uall
yin
spec
tth
eth
erm
opil
efo
rcl
ean
lin
ess.
Th
isse
n-
sor
must
be
free
ofal
ld
irt
and
lint.
Re-
clea
nif
nec
essa
ry.
5.In
sid
eC
ase
(a)
Cle
anth
esa
mple
dra
wer
and
dra
wer
base
asd
escr
ibed
abov
efo
rth
eth
erm
opil
e.R
emov
ean
yd
ebri
sth
at
may
hav
eco
llec
ted
insi
de
the
case
.
(b)
Ch
eck
once
mor
eto
mak
esu
reth
ere
isn
oco
nta
min
ati
onof
the
sam
ple
cham
ber
cavit
y.
(c)
Rep
lace
the
blo
ck,
and
inse
rtth
eri
bb
onca
ble
sock
etin
toto
the
20-p
inp
lug
onth
eb
lock
.L
ock
itin
pla
cew
ith
the
lock
ing
leve
rs.
(d)
Scr
ewth
eth
um
b-s
crew
son
the
blo
ckb
ack
inu
nti
lth
eyar
eh
and
-tig
ht.
(e)
Rep
lace
the
case
lid
and
secu
reth
eli
dsc
rew
.
6.C
onn
ect
the
WP
4Cp
ower
cord
.
36
WP
4C
4T
HE
ME
NU
S
•C
ool
sam
ple
sto
ate
mp
erat
ure
slig
htl
yb
elow
cham
ber
tem
per
-at
ure
bef
ore
star
tin
ga
read
ing.
•F
orsl
oweq
uil
ibra
tion
sam
ple
s,su
chas
pla
nt
and
moi
stso
ilsa
mp
les
(>−
0.5
MP
a),
pre
cise
read
ing
mod
em
ayyie
ldsm
all
erro
rs.
For
thes
ety
pes
ofsa
mple
s,W
ere
com
men
dyo
uu
seco
nti
nu
ous
mod
ean
dlo
gd
ata
over
tim
e(S
eeC
hap
ter
8)to
det
erm
ine
wh
eneq
uil
ibri
um
con
dit
ion
sar
ere
ach
ed.
•F
orsa
mp
les
wit
hve
ryli
ttle
wat
erh
old
ing
cap
acit
y(i
.e.
dry
san
dsa
mp
les)
,sm
all
leak
sin
the
sam
ple
cham
ber
can
cau
sew
ater
pot
enti
alto
dri
ftd
own
over
tim
e.F
ast
mod
eis
reco
m-
men
ded
for
thes
esa
mp
les.
•F
orb
est
resu
lts,
run
mos
tso
ilsa
mp
les
inp
reci
sem
od
efo
rb
est
resu
lts.
•N
ever
pla
cea
hot
orw
arm
sam
ple
ina
cool
edch
amb
er,b
ecau
seco
nd
ensa
tion
wil
lfo
rmin
sid
eth
ech
amb
er,
cau
sin
ger
rors
inre
adin
g.
4.3
Sam
ple
Equ
ilib
rati
on
Scr
een
To
see
the
tem
per
atu
red
iffer
ence
bet
wee
nyo
ur
sam
ple
an
dth
eW
P4C
,p
ress
the
low
erri
ght
bu
tton
atth
em
ain
men
u.
You
can
only
acc
ess
the
Tem
per
atu
reD
iffer
ence
scre
enw
hen
the
dra
wer
kn
obis
inth
eO
PE
N/L
OA
Dp
osit
ion
.
Th
issc
reen
show
sth
ete
mp
erat
ure
diff
eren
ceb
etw
een
the
sam
ple
(Ts)
an
dth
ech
amb
erb
lock
(Tb
).T
his
scre
enall
ows
you
toqu
ickly
chec
kif
the
sam
ple
isto
oh
ot,
wh
ich
may
cau
seco
nd
ensa
tion
insi
de
the
cham
ber
.P
ress
the
low
erri
ght
bu
tton
toex
it.
17
WP
4C
9C
LE
AN
ING
AN
DM
AIN
TE
NA
NC
E
of
IPA
or
clean
ing
solu
tion
(the
IPA
or
clean
ing
solu
tion
will
becom
eco
nta
min
ated
).
(c)W
AS
H–C
leanall
surface
edges
ofth
esa
mp
lesch
amb
erin
-clu
din
gth
eed
gew
here
the
samp
lecu
pseals
toth
ech
am-
ber
blo
ck.
You
may
need
torep
laceth
eK
imw
ipe
ifit
becom
esto
od
irtyd
urin
gth
isp
rocess.
(d)
RIN
SE
–Rep
eatstep
sb
and
cu
sing
new
Kim
wip
esw
ithd
eionized
water.
(e)D
RY
–Rep
eatstep
sb
and
cu
sing
new
,d
ryK
imw
ipes
toh
elprem
ovean
ym
oisture
remain
ing
fromth
eclean
ing.
(f)V
isually
insp
ectth
esam
ple
cham
ber
forclean
liness.
Clean
againif
necessary.
Note:
Do
not
reuse
Kim
wipes.
2.C
leanin
gth
eM
irror
Note:
Wash
han
ds
with
soap
an
dw
ater
(topreven
toils
from
con
tam
inatin
gth
eK
imw
ipetissu
ean
dbein
gtra
nsferred
toth
em
irror).
(a)W
rapa
NE
WK
imw
ipe
aroun
dth
een
dof
the
thin
plas-
ticro
d(sp
atula)
and
moisten
itw
ithisop
ropyl
alcohol
orclean
ing
solution
.
(b)
WA
SH
–Carefu
llyclean
the
mirror
with
the
moist
Kim
wip
e.
(c)R
INS
E–R
epeat
steps
ban
dc
usin
gn
ewK
imw
ipes
with
deion
izedw
ater.
(d)
DR
Y–R
epeat
steps
ban
dc
usin
gn
ew,
dry
Kim
wip
esto
help
remove
any
moistu
rerem
ainin
gfrom
the
cleanin
g.
(e)V
isually
insp
ectth
em
irrorfor
cleanlin
ess.R
e-cleanif
necessary.
Note:
Do
not
reuse
Kim
wip
es.
3.C
lean
ing
the
Optical
Sen
sor
You
will
prob
ably
cleanth
eop
ticalsen
sorw
hile
youare
clean-
ing
the
mirror,
since
they
faceeach
other
ina
verysm
all
gap.
35
4T
HE
ME
NU
SW
P4C
Note:)
Itis
impo
rtan
tth
at
Ts−
Tb
isn
egative
inord
erto
preven
tco
nden
satio
nin
side
the
sam
ple
cham
ber.
18
9C
LE
AN
ING
AN
DM
AIN
TE
NA
NC
EW
P4C
Fig
ure
10:
Vie
wof
Insi
de
Blo
ck
9.2
Cle
an
ing
Pro
ced
ure
Cle
anin
gyo
ur
WP
4Cis
am
ult
i-st
epp
roce
du
rew
hic
hin
volv
esw
ash
-in
g,ri
nsi
ng,
and
dry
ing
for
each
spec
ific
area
asou
tlin
edb
elow
:
1.C
lean
ing
the
Insi
de
Ch
amb
er
Note
:B
eex
trem
ely
care
ful
not
todam
age
the
fan
blades
inth
ech
am
ber.
The
fan
blades
are
very
fragi
le;
ifon
eof
them
brea
ks,
you
rin
stru
men
tw
ill
not
work
pro
perl
y.T
ake
extr
aca
rew
hen
clea
nin
gth
ispo
rtio
n.
(a)
Rem
ove
any
deb
ris
that
may
hav
eco
llec
ted
wit
hin
orar
oun
dth
esa
mp
lech
amb
er.
(b)
Wra
pa
new
Kim
wip
ear
oun
dth
een
dof
the
thin
pla
s-ti
cro
d(s
pat
ula
)an
dm
oist
enit
wit
his
opro
pyl
alc
ohol
orcl
ean
ing
solu
tion
.
Note
:D
on
ot
dip
au
sed
Kim
wip
ein
toyo
ur
con
tain
er
34
WP
4C
5C
AL
IBR
AT
ION
AN
DV
ER
IFIC
AT
ION
5C
ali
bra
tion
an
dV
eri
fica
tion
5.1
Veri
fica
tion
Th
eW
P4C
use
sth
ech
ille
dm
irro
rd
ewp
oint
tech
niq
ue
for
mea
-su
rin
gw
ater
pot
enti
al.
Th
isis
the
pri
mar
ym
easu
rem
ent
met
hod
,th
ough
inst
rum
ent
clea
nli
nes
sca
naff
ect
the
cali
bra
tion
.W
efi
xth
eca
lib
rati
onsl
ope
du
ring
fact
ory
cali
bra
tion
.T
he
use
rca
nad
just
the
zero
offse
tan
dca
lib
rate
succ
essf
ully
wit
han
yso
luti
onof
kn
own
wa-
ter
pot
enti
al.
We
reco
mm
end
usi
ng
the
0.5
mol
/kg
KC
lver
ifica
tion
stan
dar
dav
aila
ble
from
ME
TE
R.
5.2
Veri
fica
tion
Sta
nd
ard
s
Ver
ifica
tion
stan
dar
ds
are
spec
iall
yp
rep
ared
salt
solu
tion
sth
ath
ave
asp
ecifi
cm
olal
ity
and
wat
erp
oten
tial
.T
he
pot
assi
um
chlo
rid
e(K
Cl)
veri
fica
tion
stan
dard
sar
eac
cura
te,
easy
tou
se,
and
read
ily
avail
able
from
ME
TE
R.
Mos
tim
por
tantl
y,th
eygr
eatl
yre
du
cep
rep
arat
ion
erro
rs.
Th
est
an
dar
ds
are
pro
du
ced
un
der
ast
rict
qu
alit
yass
ura
nce
regi
me
and
are
shel
fst
able
for
one
yea
r.If
for
som
ere
ason
you
can
not
obta
inM
ET
ER
’sve
rifi
cati
onst
and
ard
san
dn
eed
tom
ake
asa
ltso
luti
onfo
rve
rifi
cati
on
,re
fer
toA
pp
end
ixA
.
Note
:T
oavo
idin
acc
ura
tew
ate
ract
ivit
yre
adin
gs,
veri
fica
tion
stan
-dard
ssh
ou
ldbe
use
don
ceim
med
iate
lyaft
erope
nin
gan
dn
ot
store
din
sam
ple
cups
for
repe
ate
du
se.
5.3
Wh
en
toV
eri
fyC
ali
bra
tion
Th
eca
lib
rati
onof
you
rW
P4C
shou
ldb
ech
ecke
dw
ith
the
KC
lst
an-
dar
db
efor
eea
chu
se.
Itca
nal
sob
ech
ecke
dby
mea
suri
ng
dis
till
edw
ater
,b
ut
this
isof
ten
not
ago
od
choi
cefo
rch
eckin
gca
lib
rati
on.
Wh
enu
sin
gd
isti
lled
wat
er,
the
hu
mid
ity
ofth
ech
amb
erap
pro
ach
es10
0%w
hic
hca
nca
use
con
den
sati
onto
occ
ur
ifth
esa
mp
leis
war
mer
than
the
cham
ber
.F
orb
atch
pro
cess
ing,
you
shou
ldre
gula
rly
chec
k
19
WP
4C
9C
LE
AN
ING
AN
DM
AIN
TE
NA
NC
E
9C
lean
ing
an
dM
ain
ten
an
ce
Th
eaccu
racyof
your
WP
4Cis
vitally
dep
end
ent
onkeep
ing
your
instru
men
tclea
n.
Du
stan
dsam
ple
deb
riscan
conta
min
ateth
esam
-p
ling
cham
ber
and
mu
stth
ereforeb
eregu
larlyclean
edou
t.T
oclea
nyo
ur
instru
men
t,carefu
llyfollow
these
instru
ctions.
You
rin
stru-
men
tsh
ips
with
aclean
ing
kit
that
shou
ldlast
one
yearw
ithregu
larclean
ings.
ME
TE
Rh
asad
dition
alclean
ing
kits
available
forp
ur-
chase
with
sup
plies
toclean
your
WP
4C.
Note:
Kim
wipe
R©are
inclu
ded
inth
eW
P4C
Clea
nin
gK
it.T
hey
are
idea
lfo
rclea
nin
gbeca
use
they
do
not
leave
mu
chof
alin
tresid
ue
likem
ost
tissues.
They
also
do
not
have
an
yoth
erco
mpo
un
ds
inth
etissu
eth
at
may
con
tam
inate
the
senso
rsin
the
WP
4C
block.N
everu
seco
tton
swabs
toclea
nth
eblock
senso
rs.M
ost
cotto
nsw
abs
con
-ta
inadhesives
an
doth
erco
mpo
un
ds
that
are
released
an
dtra
nsferred
toth
em
irror
an
doth
ersu
rfaces,
con
tam
inatin
gth
em.
9.1
Acce
ssing
the
Blo
ck
1.U
np
lug
your
WP
4C
2.R
emov
eth
ecase
lidscrew
located
onth
eb
ackp
anel.
Carefu
llyrem
oveth
elid
by
pu
lling
the
back
ofth
elid
upw
ard
and
then
slidin
gth
elid
back
(away
fromth
efron
tof
the
case)an
doff
.
3.U
nscrew
the
two
thu
mb
screws
that
secure
the
senso
rb
lock
.
4.U
np
lug
the
cable
with
the
20-pin
socket
that
attaches
the
blo
ckto
the
main
circuit
board
by
releasing
the
two
lock
ing
levers
that
areon
either
side
ofth
eso
cket.
5.C
arefully
liftth
eb
lock
straight
up
fromits
mou
nt.
Tu
rnth
eb
lock
overto
exp
oseth
ech
amb
ercav
ityas
show
nin
the
illus-
tration:
33
5C
AL
IBR
AT
ION
AN
DV
ER
IFIC
AT
ION
WP
4C
the
instru
men
tagain
stth
eK
Cl
stand
ard.
Th
isw
illalert
youto
the
possib
ilityof
contam
ination
ofth
eu
nit
orsh
iftsin
the
calib
ration
fromoth
ercau
ses.
5.4
How
toV
erify
an
dC
alib
rate
the
WP
4C
Sin
ceerro
rsin
the
calibration
value
result
inerrors
inall
valu
essu
b-
sequ
ently
measu
red,
caresh
ould
be
takento
do
itrig
ht.
Ch
eck
ing
an
dA
dju
sting
Calib
ratio
n
•P
ressth
eu
pp
errigh
tb
utton
inth
eS
ystem
Con
figu
ration
men
uto
enter
the
calibration
men
u.
You
will
be
guid
edth
rough
the
calibration
routin
eb
eginn
ing
with
instru
ction
sto
place
you
rsta
nd
ard.
•E
mp
tyth
ew
hole
vial
ofK
Cl
solution
into
asam
ple
cup
and
place
itin
the
WP
4Csam
ple
draw
er.M
akesu
reyo
ucalib
rateu
sing
the
same
typ
eof
samp
lecu
p(p
lasticor
stain
lesssteel)
that
youw
illm
akesu
bseq
uen
tm
easurem
ents
with
.
•C
arefully
slide
the
draw
erclosed
,b
eing
especially
carefulso
the
solution
does
not
splash
orsp
illan
dcon
tamin
ateth
ech
am
ber.
Ch
eckto
be
sure
the
samp
letem
peratu
reis
below
cham
ber
temp
erature
(lower
right
bu
tton).
•T
urn
the
draw
erkn
obto
the
RE
AD
position
tom
akea
read
ing.
Wh
enth
eread
ing
iscom
plete,
the
followin
gscreen
will
app
ear:
20
8T
HE
OR
Y:
WA
TE
RP
OT
EN
TIA
LW
P4C
that
are
nea
rsa
tura
tion
(lik
em
any
soil
sam
ple
s).
Asa
mp
leth
at
iscl
ose
to0.
00M
Pa
and
ison
lysl
ightl
yw
arm
erth
an
the
sen
sor
blo
ckw
ill
con
den
sew
ater
wit
hin
the
blo
ck.
Th
isw
ill
cau
seer
rors
inth
em
easu
rem
ent,
and
insu
bse
qu
ent
mea
sure
men
tsu
nti
lth
eco
nd
ensa
-ti
on
dis
app
ears
.T
he
Ts-
Tb
fun
ctio
nh
elp
sth
eu
ser
ensu
reth
at
the
sam
ple
wil
ln
otco
nd
ense
onth
ese
nso
rb
lock
.
8.4
Est
imati
ng
Osm
oti
cP
ote
nti
al
Th
eW
P4C
mea
sure
sth
esu
mof
osm
otic
and
matr
icp
ote
nti
al.
An
app
roxim
ate
valu
efo
rth
eos
mot
icp
oten
tial
can
be
fou
nd
by
mea
-su
rin
gth
eel
ectr
ical
con
du
ctiv
ity
(EC
)of
the
satu
rati
onex
tract
ofth
eso
il.
Th
eos
mot
icp
oten
tial
ofth
esa
tura
tion
extr
act
isco
mp
ute
dfr
om:
Ψos(M
Pa)
=−
0.03
6EC
(dS/m
)(2
)
Th
eos
mot
icco
mp
onen
tof
the
wat
erp
oten
tial
isth
enco
mp
ute
dfr
om:
Ψ=
Ψos(θ
s θ)
(3)
wh
ereθ
isth
evo
lum
etri
cw
ater
conte
nt
ofth
esa
mp
lean
dθ s
isth
evo
lum
etri
cw
ater
conte
nt
atsa
tura
tion
.T
he
mat
ric
pot
enti
al
isth
eto
tal
pot
enti
alm
inu
sth
eos
mot
ic. 32
WP
4C
5C
AL
IBR
AT
ION
AN
DV
ER
IFIC
AT
ION
Note
:T
he
WP
4C
wil
lau
tom
ati
call
ysh
ift
topre
cise
sam
pli
ng
mod
efo
rth
eve
rifi
cati
on
/ca
libr
ati
on
.
Th
ere
adin
gsh
ould
be
wit
hin
±0.
05M
Pa
ofth
eco
rrec
tre
adin
gof
the
KC
lst
andar
dat
that
tem
per
atu
re.
At
20◦ C
this
shou
ldb
e−
2.19
MP
a.A
t25
◦ Cth
issh
ould
be−
2.22
MP
a.
•If
you
rW
P4C
isre
adin
gw
ith
in0.
05M
Pa
ofth
eK
Cl
solu
tion
,p
ress
Exit
and
pro
ceed
wit
hre
adin
g.If
itis
not
,a
chan
gein
cali
bra
tion
may
hav
eocc
urr
ed,
orth
ese
nso
rch
amb
erm
ayb
eco
nta
min
ate
d.
For
clea
nin
gin
stru
ctio
ns,
see
Ch
ap
ter
10.
Aft
ercl
ean
ing,
rep
eat
thes
ein
stru
ctio
ns.
•If
,af
ter
clea
nin
g,you
consi
sten
tly
get
read
ings
that
diff
erfr
om
the
corr
ect
wat
erp
oten
tial
ofth
eK
Cl
by
mor
eth
an±
0.0
5M
Pa,
ach
ange
inca
lib
rati
onh
asp
rob
ably
occ
urr
ed.
Pre
ssth
eu
pp
erri
ght
bu
tton
tom
ove
the
valu
eu
p,
the
low
erri
ght
bu
t-to
nto
mov
eit
dow
n.
Wh
enit
isat
the
corr
ect
valu
efo
rth
eve
rifi
cati
onst
and
ard
,p
ress
the
Exit
bu
tton
.T
he
valu
ew
ill
be
stor
ed.
Note
:T
his
isth
eon
lym
enu
wher
eth
ese
butt
on
sca
nch
an
geth
eca
libr
ati
on
,so
you
wil
ln
ot
hu
rtan
ythin
gby
pre
ssin
gth
ese
butt
on
sin
oth
erm
enu
s.
•R
ead
the
KC
lst
and
ard
agai
nin
the
nor
mal
read
ing
mod
e.It
shou
ldre
adth
ep
rop
erva
lue.
•If
afte
rad
just
ing
the
cali
bra
tion
and
clea
nin
gth
ech
amb
eryou
stil
lar
ege
ttin
gin
corr
ect
read
ings
wh
enre
adin
gth
eK
Cl,
con
-ta
ctM
ET
ER
at50
9-33
2-56
00fo
rfu
rth
erin
stru
ctio
ns.
21
WP
4C
8T
HE
OR
Y:
WA
TE
RP
OT
EN
TIA
L
ofa
closedch
amb
er,th
enm
easurin
gth
evap
or
pressu
reof
that
head
space.
Inth
eW
P4C
,a
samp
leis
placed
ina
sam
ple
cup
,w
hich
issealed
against
asen
sorb
lock
.In
side
the
sensor
blo
ckis
afan
,a
dew
poin
tsen
sor,
atem
peratu
resen
sor,an
dan
infrared
therm
ome-
ter.T
he
dew
poin
tsen
sorm
easures
the
dew
poin
ttem
peratu
reof
the
air,an
dth
ein
fraredth
ermom
eterm
easures
the
samp
letem
per-
ature.
Th
ep
urp
oseof
the
fanis
tosp
eedeq
uilib
rium
and
tocon
trolth
eb
oun
dary
layer
cond
uctan
ceof
the
dew
poin
tsen
sor.
From
these
measu
remen
ts,th
eW
P4C
comp
utes
the
vapor
pressu
reof
the
airin
the
head
space
asth
esatu
rationvap
orp
ressure
at
dew
poin
ttem
peratu
re.W
hen
the
water
poten
tialof
the
sam
ple
an
dth
eh
eadsp
aceair
arein
equ
ilibriu
m,
the
measu
remen
tof
the
hea
dsp
acevap
orp
ressure
and
samp
letem
peratu
re(from
wh
ichsatu
rationva
-p
orp
ressure
iscalcu
lated)
givesth
ew
aterp
otentia
lof
the
sam
ple.
Inad
dition
toeq
uilib
rium
betw
eenth
eliq
uid
ph
asew
aterin
the
samp
lean
dth
evap
orp
hase,
the
intern
aleq
uilib
rium
of
the
samp
leitself
isim
portan
t.If
the
samp
leis
not
atin
ternal
equ
ilibriu
m,
one
migh
tm
easure
astead
yvap
orp
ressure
(overth
ep
eriod
ofm
easure-
men
t)w
hich
isn
otth
etru
ew
aterp
otential
ofth
esa
mp
le.
8.3
Eff
ect
of
Tem
pera
ture
on
Wate
rP
ote
ntia
l
Tem
peratu
rep
lays
acritical
rolein
water
poten
tial
determ
ination
s.M
ostcritica
lis
the
measu
remen
tof
the
diff
erence
betw
eensam
ple
and
dew
poin
ttem
peratu
re.If
this
temp
erature
diff
erence
were
inerror
by
1◦C
,an
errorof
8M
Pa
wou
ldresu
lt.In
order
forw
aterp
oten
tialm
easurem
ents
tob
eaccu
rateto
0.05
MP
a,
temp
erature
diff
erence
measu
remen
tsn
eedto
be
accurate
to0.006
◦C.
Th
eW
P4C
infrared
therm
ometer
measu
resth
ed
ifferen
cein
tem-
peratu
reb
etween
the
samp
lean
dth
eb
lock
.It
iscarefu
llycalib
ratedto
min
imize
temp
erature
errors,b
ut
achiev
ing
0.006
◦Caccu
racyis
diffi
cult
wh
entem
peratu
red
ifferen
cesare
large.
Best
accura
cyis
therefore
obtain
edw
hen
the
samp
leis
near
cham
ber
temp
eratu
re.
An
other
effect
oftem
peratu
reon
water
poten
tialoccu
rsw
ithsam
ples
31
6S
AM
PL
EP
RE
PA
RA
TIO
NW
P4C
6S
am
ple
Pre
para
tion
You
rW
P4C
will
contin
ually
prov
ide
accurate
water
poten
tialm
ea-
surem
ents
aslon
gas
itsin
ternal
sensors
aren
otcon
tamin
ated.
Care-
ful
prep
arationan
dload
ing
ofsam
ples
will
length
entim
eb
etween
cleanin
gsan
dw
illh
elpyou
avoidd
owntim
ean
drep
airs.
6.1
Ch
oosin
ga
Sam
ple
Cu
p
Th
eW
P4C
comes
with
two
typ
esof
samp
lescu
ps:
disp
osable
pla
s-tic
cup
san
dstain
lesssteel
cup
s.T
he
disp
osable
plastic
cup
sare
ad
equ
atefor
most
samp
les,b
ut
aren
otgo
od
forsam
ples
inth
ew
eten
d.
Ifyou
are
measu
ring
samp
lesw
ithw
aterp
otentia
lw
etterth
an
−1
MP
a,you
shou
ldu
seth
estain
lesssteel
samp
lecu
ps.
You
canalso
ovend
rysoil
samp
lesd
irectlyin
the
stainless
steelcu
ps
tod
e-term
ine
water
conten
tgrav
imetrically,
wh
ichis
conven
ient
ifyou
aregen
erating
soilm
oisture
characteristic
curves.
Itis
imp
ortant
ton
oteth
atyou
mu
stth
orough
lyclean
the
stainless
steelcu
ps
usin
gd
eionized
water
betw
eenu
sesto
preven
tsolu
tesfro
mcon
tamin
ating
sub
sequ
ent
sam
ples
and
causin
gartifi
ciallyn
egativeosm
oticp
oten-
tial.F
inally,
ifyou
calibrate
the
WP
4C(see
chap
ter5),
be
sure
tocalib
rate
usin
gth
esam
ety
pe
ofsam
ple
cup
that
youin
tend
tou
sefor
sub
sequ
ent
mea
surem
ents.
6.2
Pre
parin
gth
eS
am
ple
First,
place
the
samp
lein
ad
isposab
lesam
ple
cup
,com
pletely
cov-
ering
the
bottom
ofth
ecu
p,
ifp
ossible.W
P4C
may
not
be
ab
leto
accu
ratelym
easure
asam
ple
that
does
not
(orcan
not)
coverth
eb
ottomof
the
cup
.A
largersam
ple
surface
areasp
eeds
up
the
read-
ing
by
shorten
ing
the
time
need
edto
reachvap
or
equ
ilibriu
m.
Italso
increases
instru
men
taccu
racyby
prov
idin
gm
oresta
ble
infra
redsam
ple
temp
erature
measu
remen
ts.
Do
not
fill
the
samp
lecu
pm
oreth
anh
alffu
ll.O
verfilled
cup
sm
aycon
tamin
ateth
esen
sorsin
the
cham
ber,
remem
ber
more
isn
ot
nec-
essarilyb
etter.
22
8T
HE
OR
Y:
WA
TE
RP
OT
EN
TIA
LW
P4C
8T
heory
:W
ate
rP
ote
nti
al
8.1
Wate
rP
ote
nti
al
Wat
erp
oten
tial
isd
efined
asth
ep
oten
tial
ener
gy
per
un
itvo
lum
eof
wat
erin
asa
mp
le.
Th
eto
talw
ater
pot
enti
alof
asa
mp
leis
the
sum
of
fou
rco
mp
onen
tp
oten
tial
s:gr
avit
atio
nal
,m
atri
c,os
mot
ic,
and
pre
s-su
re.
Gra
vit
atio
nal
pot
enti
ald
epen
ds
onth
ep
osit
ion
ofth
ew
ater
ina
grav
itat
ion
al
fiel
d.
Mat
ric
pot
enti
ald
epen
ds
on
the
ad
sorp
tive
forc
esb
ind
ing
wat
erto
am
atri
x.
Osm
otic
pot
enti
ald
epen
ds
on
the
con
centr
atio
nof
dis
solv
edsu
bst
ance
inth
ew
ater
.P
ress
ure
pot
enti
al
dep
end
son
the
hyd
rost
atic
orp
neu
mat
icp
ress
ure
on
the
wat
er.
Th
eW
P4C
mea
sure
sth
esu
mof
the
osm
otic
and
mat
ric
pote
nti
als
ina
sam
ple
.O
ften
one
orth
eot
her
ofth
ese
pot
enti
als
wil
lb
eth
ed
omi-
nan
tfa
ctor
ind
eter
min
ing
the
tota
lp
oten
tial
.F
orex
amp
le,so
luti
ons
like
the
KC
lca
lib
rati
onst
and
ard
hav
eon
lyan
osm
otic
com
pon
ent.
Soi
lsb
ind
wat
erm
ain
lyth
rou
ghm
atri
cfo
rces
,an
dth
eref
ore
hav
em
ain
lya
mat
ric
com
pon
ent
(th
ough
salt
-aff
ecte
dso
ils
can
hav
ea
sign
ifica
nt
osm
otic
com
pon
ent)
.
8.2
Measu
rin
gW
ate
rP
ote
nti
al
Th
ew
ater
pot
enti
alof
aso
lid
orli
qu
idsa
mp
leca
nb
efo
un
dby
rela
tin
gth
esa
mp
lew
ater
pot
enti
alre
adin
gto
the
vap
orp
ress
ure
ofai
rin
equ
ilib
riu
mw
ith
the
sam
ple
.T
he
rela
tion
ship
bet
wee
nth
esa
mp
lew
ater
pot
enti
al(Ψ
)an
dth
eva
por
pre
ssu
reof
the
air
is:
Ψ=RT
M∗l
np po
(1)
wh
erep
isth
eva
por
pre
ssu
reof
the
air,po
isth
esa
tura
tion
vap
orp
ress
ure
atsa
mp
lete
mp
erat
ure
,R
isth
ega
sco
nst
ant
(8.3
1J/m
olK
),T
isth
eK
elvin
tem
per
atu
reof
the
sam
ple
,an
dM
isth
em
olec
-u
lar
mas
sof
wat
er.
Th
eva
por
pre
ssu
reof
the
air
can
be
mea
sure
du
sin
ga
chil
led
mir
ror,
andpo
isco
mp
ute
dfr
omsa
mp
lete
mp
eratu
re.
Th
eW
P4C
mea
sure
sw
ater
pot
enti
alby
equ
ilib
rati
ng
the
liqu
idp
has
ew
ate
rof
the
sam
ple
wit
hth
eva
por
ph
ase
wat
erin
the
hea
dsp
ace
30
WP
4C
6S
AM
PL
EP
RE
PA
RA
TIO
N
Mak
esu
reth
at
the
rim
and
outs
ide
ofth
esa
mp
lecu
pare
clea
n.
Wip
eany
exce
sssa
mp
lem
ater
ialfr
omth
eri
mof
the
cup
wit
ha
clea
nti
ssu
e.M
ater
ial
left
onth
eri
mor
the
outs
ide
ofth
ecu
pw
ill
con
-ta
min
ate
the
sen
sor
cham
ber
and
wil
lb
etr
ansf
erre
dto
sub
sequ
ent
sam
ple
s.T
he
rim
ofth
ecu
pfo
rms
ava
por
seal
wit
hth
ese
nso
rb
lock
wh
enth
ed
raw
erkn
obis
turn
edto
the
RE
AD
pos
itio
n.
Th
eref
ore,
any
sam
ple
mate
rial
left
onth
ecu
pri
mw
ill
be
tran
sfer
red
toth
eb
lock
,p
reve
nti
ng
this
seal
and
conta
min
atin
gfu
ture
sam
ple
s.
Ifa
sam
ple
wil
lb
ere
adat
som
efu
ture
tim
e,p
ut
the
sam
ple
cup
dis
pos
able
lid
onth
ecu
pto
rest
rict
wat
ertr
ansf
er.
For
shor
t-te
rmst
orage
(<3
hou
rs)
the
cup
lid
isac
cep
table
.If
itw
ill
be
alo
ng
tim
eb
efor
eth
em
easu
rem
ent
ism
ade,
seal
the
lid
wit
hta
pe
orP
arafi
lmR ©
com
ple
tely
aro
un
dth
ecu
pan
dli
dju
nct
ion
.
6.3
Dry
Sam
ple
s
Sam
ple
sth
ath
ave
aw
ater
pot
enti
ald
rier
than
abou
t−
300
MP
aca
nn
otb
eac
cura
tely
mea
sure
dw
ith
the
WP
4C.
How
ever
,sa
mp
les
wit
hsu
chd
ryw
ater
pot
enti
alva
lues
are
rare
.W
hen
asa
mp
lew
ater
pot
enti
alva
lue
isd
rier
than
abou
t−
300
MP
a,W
P4C
wil
ld
isp
lay
aner
ror
mes
sage
ind
icat
ing
the
low
est
read
ing
itco
uld
mak
eon
that
par
ticu
lar
sam
ple
.F
orex
ample
,if
you
wer
em
easu
rin
ga
dry
sam
ple
and
the
follow
ing
scre
enap
pea
red
:
Th
issc
reen
ind
icat
esth
atth
ela
stw
ater
pot
enti
alre
adin
gth
eW
P4C
mea
sure
don
this
sam
ple
was
−30
1.8
Meg
apas
cals
.T
her
efore
,th
eac
-tu
alw
ater
pot
enti
alof
the
sam
ple
islo
wer
than
the
inst
rum
ent
can
mea
sure
.
23
WP
4C
7C
OM
PU
TE
RIN
TE
RFA
CE
!N
op
arity!
1sto
pb
it!
Flow
control
setto
non
e
After
successfu
llycon
nectin
gth
eW
P4C
toyou
rcom
pu
teran
du
pon
comp
letionof
aw
ateractiv
ityread
ing,
the
data
will
be
disp
layedin
the
termin
alp
rogramin
the
format
asfollow
s:m
easurem
ent
time
(min
utes),
samp
letem
peratu
re,an
dw
aterp
otential
(inb
othM
ega-P
ascals
and
pF
).F
igure
9sh
ows
asam
ple
return
.
Figu
re9:
Sam
ple
Data
Retu
rn
29
6S
AM
PL
EP
RE
PA
RA
TIO
NW
P4C
6.4
Sam
ple
san
dT
em
pera
ture
Ifsam
ples
arew
armer
than
the
cham
ber
wh
enth
eyare
pla
cedin
it(T
s-Tb
isa
positive
nu
mb
er),con
den
sationm
ayoccu
ran
dm
oisture
may
cond
ense
insid
eth
eb
lock
.In
order
top
revent
this,
follow
steps
1an
d2.
1.P
laceyou
rsam
ple
inth
ech
amb
er,slid
eth
ed
rawer
closedan
dp
ressth
elow
errigh
tb
utton
toaccess
the
samp
letem
peratu
rescreen
and
look
atth
etem
peratu
red
ifferen
ce.If
the
sam
ple
temp
erature
issh
own
tob
ea
positive
nu
mb
er,take
the
sam
ple
out
imm
ediately
and
letit
cool
ona
coldsu
rfacew
ithth
ecu
plid
onit
top
reserve
the
moistu
re.D
on
otco
ol
the
sam
ple
too
mu
ch,
orth
eeq
uilib
rium
time
will
be
length
ened
(ideally
the
Ts-T
bw
illb
eb
etween
−0.5
and
0).
2.A
fterco
oling
itfor
am
inu
teor
so,p
laceth
esam
ple
back
inan
dn
oteth
etem
peratu
red
ifferen
ce.If
itis
close
enou
gh
toth
eb
lock
temp
erature,
turn
the
kn
obto
the
RE
AD
position
tob
eginread
ing.
Th
ereis
alin
earrelation
ship
betw
eenth
esam
ple
dew
poin
ttem
per-
ature
and
itsw
aterp
otential.
Th
ed
ewp
oint
decreases
−0.12
◦Cp
erM
Pa.
For
exam
ple,
avery
dry
samp
leat−
40M
Pa
canb
e4.8
◦C(−.12∗−
40)ab
oveth
ech
amb
ertem
peratu
rew
ithou
tcon
den
s-in
g.A
samp
leat−
1M
Pa
(fairlyd
ryfor
most
soils)ca
nb
e0.1
2◦C
above
the
cham
ber
temp
erature
with
out
cond
ensin
g.T
herefore,
ifyou
kn
owth
egen
eralran
geof
your
samp
lew
aterp
otentia
l,you
canga
uge
at
wh
ichtem
peratu
reit
will
cond
ense
moistu
re.F
orsam
ples
that
arem
oreth
an1
◦Cb
elowch
amb
ertem
peratu
re,th
eW
P4C
waits
until
their
temp
erature
increases
to1
◦Cb
elowch
am
ber
tem-
peratu
reto
starta
readin
g.R
eadin
gsare
therefore
sped
up
ifsa
mp
letem
peratu
reis
just
alittle
below
cham
ber
temp
erature.
24
7C
OM
PU
TE
RIN
TE
RFA
CE
WP
4C
Fig
ure
8:A
qu
aLin
kS
cree
nS
hot
7.2
Usi
ng
aC
om
mu
nic
ati
on
Pro
gra
m
Th
ere
are
seve
ral
term
inal
pro
gram
opti
ons.
ME
TE
Rh
asit
sow
nte
rmin
alp
rogr
am(D
ecaT
erm
)w
hic
hca
nb
ed
own
load
edfr
om:
htt
p:/
/sof
twar
e.m
eter
grou
p.c
om/D
ecaT
erm
.zip
.T
wo
oth
erop
tion
sar
eT
eraT
erm
,w
hic
his
afr
eep
rogr
amth
atca
nb
efo
un
don
the
Inte
rnet
and
Hyp
erte
rmin
alw
hic
hca
me
stan
dar
dw
ith
Win
dow
sp
rior
toW
ind
ows
7.
To
use
any
ofth
ese
term
inal
pro
gram
sw
ith
you
rW
P4C
,fo
llow
the
inst
ruct
ion
sfo
rth
ep
rogr
amw
ith
the
foll
owin
gse
ttin
gs.
Be
sure
top
ower
onth
eW
P4C
pri
orto
con
nec
tin
gth
eU
SB
inte
rfac
eca
ble
toyo
ur
com
pu
ter.
•C
hoos
eco
rrec
tC
omp
ort
•S
et/V
erif
yC
omP
rop
erti
es
!B
its
per
seco
nd
9600
!8
Dat
abit
s
28
WP
4C
6S
AM
PL
EP
RE
PA
RA
TIO
N
6.5
Measu
rin
gP
lant
Sam
ple
s
Th
eW
P4C
can
be
use
dto
mea
sure
the
wat
erp
ote
nti
alof
leav
esan
dpla
nt
mat
eria
l.P
leas
ere
fer
toth
eap
pli
cati
onn
ote:
Mea
sure
-m
ent
ofL
eaf
Wat
erP
oten
tial
Usi
ng
the
WP
4,w
hic
hca
nb
efo
un
dat
ww
w.m
eter
grou
p.c
om.
6.6
Takin
ga
Read
ing
On
ceyo
uh
ave
pre
par
edyou
rsa
mp
le,
you
are
read
yto
take
read
ings.
Fol
low
step
s1
thro
ugh
5to
take
read
ings
.
1.T
urn
the
sam
ple
dra
wer
kn
obto
the
OP
EN
/LO
AD
pos
itio
nan
dp
ull
the
dra
wer
open
.
2.P
lace
you
rp
rep
ared
sam
ple
inth
ed
raw
er.
Chec
kth
eto
pli
pof
the
cup
tom
ake
sure
itis
free
from
sam
ple
resi
du
e(r
emem
-b
er,
anov
er-fi
lled
sam
ple
cup
wil
lco
nta
min
ate
the
cham
ber
sen
sors
).
3.C
aref
ull
ysl
ide
the
dra
wer
clos
ed,
bei
ng
esp
ecia
lly
care
fulif
you
hav
ea
liqu
idsa
mp
leth
atm
aysp
lash
orsp
ill
and
conta
min
ate
the
cham
ber
.
4.A
cces
sth
esa
mp
lete
mp
erat
ure
men
u(p
ress
low
erri
ght
bu
tton
)to
watc
hth
ete
mp
erat
ure
diff
eren
ceb
etw
een
the
sam
ple
an
dth
ein
stru
men
t.
5.T
urn
the
sam
ple
dra
wer
kn
obto
the
RE
AD
pos
itio
nto
sealth
esa
mp
lecu
pw
ith
the
cham
ber
.T
he
inst
rum
ent
wil
lb
eep
on
ce,
and
the
gree
nli
ght
wil
lfl
ash
once
toin
dic
ate
that
the
read
ing
cycl
eh
asst
arte
d.
Inab
out
40se
cond
s,th
efi
rst
mea
sure
men
tw
ill
be
dis
pla
yed
.
6.7
How
WP
4C
takes
Read
ings
Th
eW
P4C
cool
edm
irro
ris
contr
olle
dat
the
cham
ber
dew
poin
tan
dit
ste
mp
erat
ure
ism
easu
red
..W
hen
the
inst
rum
ent
has
fin
ish
edit
sre
adcy
cle,
the
wat
erp
oten
tial
isd
isp
laye
d,
acco
mp
an
ied
by
the
LE
Dfl
ash
and
bee
per
(if
you
hav
eth
eb
eep
eren
able
d).
25
WP
4C
7C
OM
PU
TE
RIN
TE
RFA
CE
7C
om
pu
ter
Inte
rface
You
rW
P4C
comes
with
aR
S-232
toU
SB
Serial
cab
le.U
sing
this
cable,
youcan
conn
ectto
your
WP
4Can
dsen
dw
ateractiv
ityd
atato
acom
pu
terfor
furth
eran
alysis
and
storage.T
he
interface
isru
nth
rough
the
Aqu
aLin
k4
Softw
areor
aterm
inal
com
mu
nication
pro-
gram
.
Note:
Ifyo
uco
mpu
terdoes
not
have
aU
SB
port,
you
can
use
aU
SB
toR
S-2
32
adapter.
7.1
Aqu
aL
ink
4S
oftw
are
An
option
alsoftw
arep
rogram,
Aqu
aLin
k4,
isavailab
lefor
use
with
you
rW
P4C
.A
qu
aLin
k4
isa
Win
dow
sb
asedp
rogramd
esigned
for
data
collectionan
dcu
stomized
report
generatio
n.
Aqu
aL
ink
4logs
water
activity,
temp
erature,
time
ofm
easurem
ent,
and
date
stamp
salon
gw
ithoth
erin
formation
.A
quaL
ink
4also
has
sam
ple
iden
ti-fi
cationan
dcom
men
tfi
elds
that
youcan
use
toh
elpan
notate
the
data
your
WP
4Cis
gatherin
g.
A30
day
trialU
SB
ofth
isp
rogramis
attached
toth
efron
tcover
ofth
ism
anu
al.If
youare
interested
inp
urch
asing
alicen
seof
Aqu
aLin
k4,
contact
ME
TE
Ror
your
local
distrib
utor.
On
the
nex
tp
ageis
asam
ple
pictu
reof
the
Aqu
aLin
k4
program
:
27
6S
AM
PL
EP
RE
PA
RA
TIO
NW
P4C
Cau
tion
s
•N
ever
leave
asa
mp
lein
your
WP
4C
afte
ra
read
ing
has
fin
ished
.T
he
sam
ple
may
spill
an
dconta
min
ate
the
instru
ment
cham
ber
ifth
ein
strum
ent
isaccid
enta
llym
oved
or
jolte
d.
•N
ever
tryto
move
you
rin
strum
ent
afte
rlo
ad
ing
asa
m-
ple
.M
ovem
ent
may
cau
seth
esa
mp
lem
ate
rial
tosp
illan
dconta
min
ate
the
sam
ple
cham
ber.
•T
ake
specia
lcare
not
tom
ove
the
sam
ple
dra
wer
too
qu
ickly
wh
en
load
ing
or
un
load
ing
liqu
idsa
mp
les,
inord
er
toavoid
spillin
g.
•If
asa
mp
leh
as
ate
mp
era
ture
that
ish
igh
er
than
the
WP
4C
cham
ber
(Ts-T
bis
ap
ositiv
enu
mb
er),
take
the
sam
ple
ou
tim
med
iate
ly,
pu
ta
cap
on
it,an
dcool
it.W
arm
sam
ple
scan
cau
secon
den
satio
nin
the
cham
ber
an
dad
verse
lyaff
ect
sub
sequ
ent
read
ings.
•T
he
physic
al
tem
pera
ture
of
the
instru
ment
shou
ldb
eb
etw
een
5◦C
an
d40
◦C.T
he
WP
4C
will
measu
resa
m-
ple
sb
etw
een
this
ran
ge
qu
ickly
an
daccu
rate
ly.
•If
you
are
read
ing
an
da
trian
gu
lar
warn
ing
sym
bol
ap
pears
inth
eto
prig
ht
corn
er
of
the
disp
lay,
this
in-
dic
ate
sth
at
the
mirro
rh
as
becom
eto
od
irtyto
giv
eaccu
rate
measu
rem
ents.
You
will
need
tocle
an
the
mirro
ran
dch
am
ber
befo
recontin
uin
gto
sam
ple
.For
more
deta
ilsab
ou
tth
issy
mb
ol,
ple
ase
refe
rto
Ch
ap
ter
12.
For
cle
an
ing
instru
ctio
ns,
refe
rto
Ch
ap
ter
10.
26
