ЕВРО-АЗИАТСКОЕ СОТРУДНИЧЕСТВО ГОСУДАРСТВЕННЫХ МЕТРОЛОГИЧЕСКИХ УЧРЕЖДЕНИЙ (KOOMET) EURO-ASIAN COOPERATION OF NATIONAL METROLOGICAL INSTITUTIONS (COOMET) June 2015 COOMET PROJECT NO. 568/UA/12 SUPPLEMENTARY COMPARISON COMPARISONS OF THE REFERENCE MEASURING INSTRUMENTS OF SURFACE PARAMETERS COOMET.L-S13 Comparison of the reference measuring instruments of surface parameters FINAL REPORT Pilot laboratory: Research Laboratory of Geometrical Quantities Measurements. NMI name and abbreviation: National Scientific Center “Institute of Metrology” (NSC IM). Contact person: Kupko Vladimir Semenovich Address: Mironositskaya Str., 42, Kharkov 61002, Ukraine Telephone: (057)700-34-09 Fax: (057)700-34-47 Е-mail: [email protected]
Transcript
ЕВРО-АЗИАТСКОЕ СОТРУДНИЧЕСТВО ГОСУДАРСТВЕННЫХ МЕТРОЛОГИЧЕСКИХ УЧРЕЖДЕНИЙ (KOOMET)
EURO-ASIAN COOPERATION OF NATIONAL METROLOGICAL INSTITUTIONS (COOMET)
June 2015
COOMET PROJECT NO. 568/UA/12
SUPPLEMENTARY COMPARISON
COMPARISONS OF THE REFERENCE MEASURING INSTRUMENTS OF SURFACE PARAMETERS
COOMET.L-S13 Comparison of the reference measuring instruments of surface parameters
FINAL REPORT
Pilot laboratory: Research Laboratory of Geometrical Quantities Measurements. NMI name and abbreviation: National Scientific Center “Institute of Metrology” (NSC IM). Contact person: Kupko Vladimir Semenovich Address: Mironositskaya Str., 42, Kharkov 61002, Ukraine Telephone: (057)700-34-09 Fax: (057)700-34-47 Е-mail: [email protected]
1. Participants of the comparisons Table 1 № NMI Address Abbreviation
of NMI Contact person
E-mail, telephone, fax
1 National Scientific Center “Institute of Metrology”, Ukraine
2. Comparisons organization 2.1 The comparisons principle. 2.1.1 The scheme of comparisons – round-robin. 2.1.2 Pilot laboratory – NSC “Institute of Metrology”. 2.1.3 The objectives of comparisons are:
- determination of the equivalency level of the standards; - verification of CMC data.
2.2 The measurement schedule for participants is given in Table 2. Table 2
Date of comparisons NMI Abbreviation According to schedule Actual
NSC IM September 2013 September 2013 FGUP VNIIMS October 2013 October 2013 The comparisons were performed by use of comparison gauge, which is a property of NSC “Institute of Metrology”.
3. The basic characteristics of comparison gauge
Figure 1. Comparison gauge
Silicon plate
Aluminum base
Position of marks
3.1 Comparison gauge is a roughness gauge of type A1 which represents a silicon slab with thickness of 0,5 mm on the aluminum base with thickness of 8,5 mm. It has two height differences. The overall dimensions of the gauge are 20409 mm (Figure 1). 3.2 The main characteristics of the gauge are given in Table 3. The nominal height d is 0,25 μm and 49 μm. Passage width 1 is 1,3 μm and 43,3 μm respectively. Passage width 2 is 1,4 μm and 30,8 μm respectively. Bottom width is 192,6 μm and 135,3 μm respectively. Table 3
4. Measurement method The basis of measurement is the definition of the length unit which is lined up to the helium-
neon laser wavelength. The application of the standard laser source allows direct obtaining of data binding of the
measurement parameters to the unit standard by displacement interferometer and microinterferometer that produces linear conversions of roughness standard profile and gets its image on the fringe pattern. Advanced digital photo/video imaging system of the fringe pattern, algorithm and specific computer programs testing provides required accuracy of the image processing and determination of roughness parameters.
5. Environmental conditions during the comparisons
5.1 Environmental conditions in which gauge measurements were held are given in Table 4.
Table 4
Characteristic description Characteristics value Gauge temperature, С 20 ± 1 Air temperature, С 20 ± 1 Relative humidity, % 58 ± 20 Atmospheric pressure, mm Hg 760 ± 20
6. Measurement instrumentation, conditions and results 6.1. NSC “Institute of Metrology”, Ukraine 6.1.1 Measurement instrumentation
National primary standard of the length unit for measurements of the parameters of roughness Rmax, Rz and Ra in the range from 0,025 μm to 1600 μm (hereinafter referred to as the standard) consists of the complex of such measuring equipment and devices:
Microinterferometric apparatus which includes: a) microinterferometer; b) imaging system for digital photo and video information; c) source of monochromatic radiation – He-Ne gas laser stabilized on He line and the
white radiation source; interferometric displacement controller IP-1; temperature, humidity and air pressure measuring device; management system – calculating device based on computer work;
software of the standard roughness gauge with the regular profile and one-line degree of roughness height. General view of the type standard is given in the Photo (Figure 2).
Figure 2. Standard DETU 01-04-07
6.1.2 Measurement conditions. The measurements met the following conditions: air temperature (20±0,1) ˚С; absolute air humidity (10±3) mm Hg; atmospheric pressure (98 – 102) kPa. 6.1.3 Measurement results Measurement results of the height differences of the comparison standard hold in NSC “Institute of metrology” are given in Table 5.
Parameter Rmax is calculated according to the formula: Rmax = Hλ / [2g], (1),
where H – the distance between a line of profile peaks and a line of profile valleys;
λ – the radiation wavelength;
g – the width of the interference fringe.
The refraction index of air is calculated according to Edlen equation:
ettppn
88
6
1060794336,5100036610,01
100133,0817,013639197,381 (2);
where: n - the refraction index of air;
p – atmospheric pressure value in mm Hg;
t – air temperature in °С;
е – air humidity in mm Hg.
The calculation of uncertainty budget when measuring the roughness parameter Rmax is
presented in Tables 6-7.
Table 6. The evaluation of measurement uncertainty of roughness parameters Rmax for
0,251 μm.
Quantity, symbol Unit Estimation value Interval Sensitivity
coefficient
Contribution to the standard uncertainty
Uncertainty contribution
1 2 3 4 5 6 7
Uncertainty of type A evaluation
The distance between a line of profile peaks and a line of profile valleys, H
px 586 1 Rmax/Н μm/px 0,0017
1·0,0017= 1,7·10-3 μm
The width of the interference fringe, g
px 186 0,6 Rmax/g μm/px
0,00538
0,6·0,00538
=3,2·10-3
μm
Correlation index - 0,9
Roughness parameter Rmax
μm 1,0 0,0029 μm
Uncertainty of type B evaluation
Wavelength, λ μm 0,632990798 1,15·10-8
Rmax/λ=
1,0/0,63299 = 1,58
1,15·10-8· 1,58= =1,82·10-8
μm can be neglected
The distance between a line of profile peaks and a line of profile valleys, H Uncertainty components:
px
586
Rmax/Н μm/px
uB1 (H) 0,1074
uB2 (H) 0,3406
uB3 (H) 0,2713
uB4 (H) 0,0346
uB5 (H) 0,0981
uB(H) 0,4619 0,00170 0,785·10-3μm
The width of the interference fringe, g, Uncertainty components
px 186 Rmax/g μm/px
uB1 (g) 0,1074
uB2 (g) 0,1074
uB3 (g) 0,0860
uB4 (g) 0,0107
uB5 (g) 0,0981
uB (g) 0,2006 5,38·10-3 1,079·10-3μm
Standard uncertainty of type B UB (Rmax)
μm 1,0 0,0013 μm
Combined standard uncertainty UC (Rmax)
μm 0,0019 μm
Degree of freedom ν 11
Coverage factor К at the level of confidence of 99 %
3,1
Expanded uncertainty UP (Rmax)
μm 0,0059 μm
Table 7. The evaluation of measurement uncertainty of roughness parameters Rmax for 49 μm.
Quantity, symbol Unit Estimation value Interval Sensitivity
coefficient
Contribution to the standard uncertainty
Uncertainty contribution
1 2 3 4 5 6 7
Uncertainty of type A evaluation
Roughness μm 0,169
parameter Rmax
Uncertainty of type B evaluation
Roughness parameter Rmax, Uncertainty components:
μm 0,002 0,016 2,57 0,006
Component caused by the curvature of interference fringes uB1
0,0003
Component caused by the optical distortion of the optical path uB2
0,0023
Component caused by the different levels of black uB3
0,0018
Component caused by the inclination of the measuring object uB4
0,00023
Component caused by the influence of the aperture uB5
0,00029
Component caused by the thermal displacement of the fringes uB6
3,75·10-6
Component caused by the displacement measurement uncertainty IP-1 uB7
0,0133
Standard uncertainty of type B UB (Rmax)
μm 1,0
0,0149 μm
Combined standard uncertainty UC (Rmax)
μm
0,1697 μm
Degree of freedom ν 11
Coverage factor К at the level of confidence of 99 %
3,1
Expanded uncertainty UP (Rmax)
μm
0,5259 μm
The expanded uncertainty for 0,25 μm is U199 (Rmax) = 0,0059 μm. The expanded uncertainty for 49,0 μm is U299 (Rmax) = 0,5259 μm. 6.2 FGUP VNIIMS, Russia 6.2.1 Measurement instrumentation Metrological instrumental complex for the measurement of the relief and roughness
parameters of nanometer range consists of four types of measuring instruments (MI): contact profilometers, scanning probe microscope (SPM), interference microscope and precision interferometers.
Heterodyne detectors with resolution up to 0,1 nm are installed into the above mentioned MI, that provides the accuracy requirements that meet international standards of leading countries of the world (PTB – Germany, NIST – USA, NPL – UK).
The indicated MIs are equipped with heterodyne detectors: - heterodyne laser displacement interferometers of Michelson in scanning probe
microscopes; - contact profilometers; - stabilized He-Ne lasers in phase-shifting Fizeau interferometers for relief control and Miro
interferometers in interference microscopes for roughness control of nanometer range
Figure 3 – Contact profilometer with a binding to the wavelength of stabilized laser
radiation
Figure 4 Precision laser Fizeau interferometer for the measurement of relief parameters for nanostructured surfaces
6.2.2 Measurement conditions. The measurements met the following conditions: air temperature (20±0,1) ˚С; absolute air humidity (10±3) mm Hg; atmospheric pressure (98 – 102) kPa. 6.1.3 Measurement results
Laser profilometer “Talystep”
Laser interferometer
profilometer sonde
sonde
base Piezo-table for scanning on XYZ
Measurement results of the height differences of the comparison standard hold in FGUP VNIIMS are shown in Table 8.
Table 8. Research results of gauge No.016 characteristics
Standard deviation 0,002 0,15 Parameter Rmax is calculated according to the formula
Rmax = Rmaxи + с + Rq + м + о, (11)
where Rmax – the measured value of gauge parameter Ra;
Rmaxu – the arithmetic mean value of ten measurements of gauge parameter Rmax;
с - measurement system correction;
Rq - correction to the inherent noise of the system;
м – standard gauge correction;
о - reading error of last sampling echelon
The calculation of uncertainty budget when measuring the roughness parameter Rmax for the
range from 0 to 0,2 mm is presented in Table 9.
Table 9 Component quantity Characteristics of component quantity
1 2 Rmaxu – the arithmetic mean value of parameter Rmаx grade measurements
Uncertainty of type A Distribution type: normal Standard uncertainty:
1
)maxmax()max( 1
2
nn
RRRu
n
iиi
и
)ma( иxRu = 0,0019 μm
с - correction for Form Talysurf measurement system
Uncertainty of type B Distribution type: rectangular Estimation value: 0 Interval containing the component quantity value: ± 0,0085 μm Standard uncertainty: 0,0049 μm
Interval containing the component quantity value с determined in the result of the research of the metrological characteristics of the standard. Maximum value of measurement uncertainty Rmax = ± 0,0085 μm obtained on the measurement range 0-0,2 mm.
Standard uncertainty value u(с) is found as the standard deviation with rectangular distribution u(с) = Rmax / 3 =
0,0085/ 3 =0,0049 μm Rq – correction to the inherent noise of the Form Talysurf system
Uncertainty of type B Distribution type: rectangular Estimation value: 0 Interval containing the component quantity value: 0,002 μm Standard uncertainty: 0,00115 μm
Intrval ± аRq containing the component quantity value Rq specified in the calibration certificate issued by calibration laboratory of the company «Taylor Hobson». Inherent system noise Rq = 0,002 μm, it follows that аRq = ± 0,002 μm.
Standard uncertainty value u(Rq) is found as the standard deviation with rectangular distribution u(Rq) = аRq / 3 =
0,002/ 3 = 0,00115 μm м - standard gauge correction Uncertainty of type B
Distribution type: rectangular Estimation value: 0 Interval containing the component quantity value: ± 0,002 μm Standard uncertainty: u (м) = 0,00115 μm
Interval ± аm containing the component quantity value м is determined according to data specified in the passport of the gauge.
Standard uncertainty value u(Rq) is found as the standard deviation with rectangular distribution u(м) = ам / 3 =
0,002/ 3 = 0,00115 μm о – reading error of last sampling echelon Uncertainty of type B
Distribution type: rectangular Estimation value: 0 Interval containing the component quantity value: 0,003 мкм Standard uncertainty: u (о) = 0,00087 м
Interval containing the component quantity value о is determined according to the system capability. On the measurement range 0-0,2 mm system resolution is 0,003 μm. This value is specified in operational documentation of Form Talysurf system.
Standard uncertainty value u(о) is found as standard deviation with rectangular distribution u(о) = 0,003 /2 3 = 0,00087 μm
Expanded uncertainty U max)(R is obtained by multiplying the standard uncertainty state
u max)(R by the coverage factor k = 2 assuming the normal distribution for the 95% confidence
level.
U max)(R = 2 × u max)(R = 0,0056×2 = 0,011 μm.
The measurement of comparison gauge of NSC “Institute of Metrology” and FGUP VNIIMS on section 1 of gauge No.16
0,225
0,23
0,235
0,24
0,245
0,25
0,255
0,26
Figure 5 – Results of the research of Rmax characteristic on section 1 of gauge No. 016, blue colour – the amount of Rmax of the average measurement value, red colour – the border of expanded measurement uncertainty.
The measurement of comparison gauge of NSC “Institute of Metrology” and FGUP VNIIMS
on section 2 of gauge No.16
48,6
48,8
49
49,2
49,4
49,6
49,8
50
Figure 6 - Results of the research of Rmax characteristic on section 2 of gauge No. 016,
blue colour – the amount of Rmax of the average measurement value, red colour – the border of expanded measurement uncertainty.
7 Results of comparisons and their analysis During comparisons each laboratory-participant carried out 10 measurement of Rmax
parameters on sections 1 and 2 of gauge No. 016 each. Maximum differences of the results of Rmax parameter measurements are given in Table 10.
NSC “Institute of Metrology”
FGUP VNIIMS
Rmax, μm
Rmax, μm
NSC “Institute of Metrology”
FGUP VNIIMS
Table 10 Maximum differences of the results of Rmax parameter measurements on section 1, μm
Maximum differences of the results of Rmax parameter measurements on section 2, μm
NSC "Institute of Metrology"
FGUP VNIIMS NSC "Institute of Metrology"
FGUP VNIIMS
0.011 0.018 0.56 0.174 Maximum differences of the results of Rmax parameter measurements of the comparison
participants on sections 1 and 2 of the measure No. 016 are given in Table 11. Table 11
Maximum differences of the results of Rmax parameter measurements on section 1, μm
Maximum differences of the results of Rmax parameter measurements on section 2, μm
FGUP VNIIMS - NSC "Institute of Metrology" FGUP VNIIMS - NSC "Institute of Metrology" 0.007 0.368
The results of measurements of the comparison participants were verified as per the level of equivalence of the standards.
As only two countries (laboratories) take part in the comparison, the level of equivalence can be expressed quantitively by two following quantities (dj , U(dj)), i.e.
- by deviation from the reference value (RV) of measurement value of each institute dj - by expanded uncertainty U(dj) of this difference at the level of credibility of 95%
RVRd ij max , (4)
jj dudU 2 , (5)
RVRudu ij max22 (6)
jj dud 2 (7) The difference of the results of dj measurements is given in Table 12. Table 12
The difference of the average values results of dj measurements of Rmax parameter on section 1,
μm
The difference of the average values results of dj measurements of Rmax parameter on section
2, μm 0.001 0.019
Expanded uncertainty U(dj) of the results of measurements is given in Table 13. Table 13
Expanded uncertainty U(dj) of the difference of the results of dj measurements of Rmax
parameter on section 1, μm
Expanded uncertainty U(dj) of the difference of the results of dj measurements of Rmax
parameter on section 2, μm 0.025 1.052
As it can be seen from Tables 12 and 13 at comparison of dj and U(dj) there is carries out
condition (7), correspondingly, the standards being compared are equivalent. Conclusions: The results of the comparison conducted for standard instruments of FGUP
VNIIMS and NSC "Institute of Metrology" at height differences of 0.25 μm and 49 μm can be recognized as positive. Comparison of standards of FGUP VNIIMS and NSC "Institute of Metrology" shall be continued within a new project.
