EZ SDIEZ SDI™Automatic Silt Density Monitor
Monitoring the fouling tendency of RO feed-water has long been a challenge. Usually foul-ing is not noticed until the RO membranes needcleaning, resulting in expensive downtime or, worse yet,membrane replacement.
Numerous methods have been used to measure the foulingtendency of feed waters, including turbidity, particle count-ing, and manual silt density index (SDI) testing. It is difficult
to correlate turbidityand particle countingto membrane foulingsince they do notdirectly measure thefouling or “plugging”nature of the particlesin suspension. Sincethe manual SDI testmeasures this plug-ging tendency, it hasproven useful in indicating fouling ten-dencies. However, themanual SDI testingmethod is tedious andtime-consuming.
The RODI Systems EZ SDI™ automatically and consistentlymonitors the silt density index of RO feed water. Operatorscan quickly and regularly check the effectiveness of the ROpretreatment system without bothering with labor-intensivemanual tests.
It is easy to install, easy to operate, and sells for a fraction of the cost of other automatic SDI testingequipment.
The EZ SDI™ is microprocessor controlled and fully auto-matic. The monitor is housed in a NEMA 4X enclosure andis designed for permanent installation in industrial environ-ments. The filter holder allows the use of standard 25mm testfilters available from a number of suppliers. Replacing themedia is a two-minute process and the test is initiated withthe press of a button.
A blinking indicator notifies the operator of the completionof the test. The SDI results may then be read from the LCDdisplay. The display is equipped with an LED backlight mak-ing it easy to see the results in any environment.
The test pressure is controlled with a high-quality internalpressure regulator which can accommodate inlet pressuresabove 1000 psi. This allows the sample to be taken from thehigh pressure side of the RO feed pump thus eliminatingcumbersome and expensive sample boost pumps. The testpressure is constantly displayed on the LCD and the EZSDI™ alarms and aborts the test if the pressure falls outsideof ASTM specifications.
RODIsystems
The EZ SDI™· Fully automatic· Designed for on-line
operation· Fast and easy filter media
replacement· Uses standard filter media
ph 505-334-5865 • fax 505-334-5867 • www.rodisystems.comEmail: [email protected] • 936 Highway 516 • Aztec, NM 87410-2828
EZ SDI™ and EZ SDI-4™ are trademarks of RODI Systems Corp.
RODI Systems offers a cost-effective, automatic SDI monitoring system.
Complies withASTM D4189-95
Operation
The EZ SDI™ is now available ina four-test version, allowing fourseparate SDI tests beforereplacing filters.
Tests may be activated:• Manually from keypad• Time interval• External trigger (dry contact)
TechnicalEZ SDI™EZ SDI™
PrincipleThe EZ SDI™ uses the same testing method as specifiedin ASTM D 4189-95. This standard method indicates thequantity of particulate matter in water and is applicableto relatively low (
