Millipore SDI instrument filter membrane

So what is a manually measured SDI instrument?
The manual SDI pollution index measuring instrument consists of an inlet pipe, a pressure regulating valve, a pressure gauge, and a membrane replacement filter. When measuring the SDI value, only a stopwatch and a 500ml measuring cylinder are needed for testing. The manual SDI pollution index tester can be installed on site and stored in the toolbox after on-site measurement and testing, or it can be directly fixed at the sample water pipeline with a fixture. After testing, the outlet ball valve can be closed. The manual SDI pollution index tester is small in size and light in weight, but the entire testing process requires personnel to operate it without leaving their hands, which is quite tedious. Sometimes we also refer to this SDI instrument as an online SDI measuring instrument or a portable SDI measuring instrument.

How is SDI calculated?
Simple SDI can automatically calculate the SDI value of a water sample based on the attenuation of permeate flow rate when it passes through a new 0.45 μ m filtration membrane in the SDI instrument within 15 minutes. In order to ensure the measurement accuracy of water sample permeation flow rate, the Simple SDI instrument maintains a constant inlet pressure of 30psi.
Measure the flow rate during the collection of 500mL water samples at the beginning of the experiment and for the next 5, 10, and 15 minutes. The SDI value (percentage attenuation per minute) indicates the degree of membrane blockage that may be caused by the particle and axillary material content in the influent. The American Society for Testing and Materials (ASTM) D4189-95 specifies that a time interval of 15 minutes is required for accurate and standardized SDI value testing. The SDI values of 5 minutes and 10 minutes are only estimates of the SDI value of 15 minutes (SDI15).
In addition to calculating the SDI value for 15 minutes, the attenuation of water sample permeation flow rate can also be determined by converting the SDI value into another indicator parameter: fouling factor (PF value), which provides a reference for determining the degree of fouling of the RO membrane. The PF value percentage is relatively high, and the RO membrane may be blocked by particles at a faster rate. The PF value is between 1% and *, which means that the membrane component will be clogged.
Millipore SDI instrument filter membraneCharacteristics:
*It can effectively remove impurities such as colloids and suspended solids from raw water, as reverse osmosis systems are highly sensitive to them.
*Having a uniform water distribution method, it can retain the filter material, balance the resistance of the filter layer, prevent bias flow, and achieve the desired effect of the filter; Can meet the long-term requirements of reverse osmosis membrane for pollution index SDI.
*High quality filter media is selected as the filling material, and the unevenness coefficient of the filter media is 2-3 to ensure good filtration effect, and there will be no backwashing or disorderly layer phenomenon.
*Choose a lower operating flow rate (normal operation<10 m3/h) to accommodate the possibility of water quality deterioration in the future.
Millipore SDI instrument filter membraneIt is an SDI measuring instrument in the form of a toolbox. When the user arrives at the site, they connect the water and electricity, replace the SDI membrane, eliminate bubbles, and under the condition that the pressure is met, the machine will automatically start running the test. After the test is completed, the results can be directly read on the display screen. The automatic portable SDI instrument simplifies the testing process of SDI values, freeing up the hands of testers, and is now increasingly popular among users. We also refer to this SDI instrument as an online SDI instrument because it can be tested online.