Testing The Quality Of The Membrane - SpectraPure Mega MaxCap Installation And Operating Manual

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TESTING THE QUALITY OF THE MEMBRANE:

The performance of a RO membrane is measured by its ability to reject
salts or TDS (Total Dissolved Solids). Use the TDS Meter located on the left
side of your system for this procedure.
General Procedure:
1. Slide the switch on the Left-Side TDS meter all the way to the left (IN).
Measure the tap water TDS. (Call it X)
2. Run the system for 15 -20 minutes.
3. Slide the switch on the Left-Side TDS meter to the right (OUT).
Measure RO product water TDS. (Call it Y).
4. Subtract RO water TDS from tap water TDS. (X - Y)
5. Divide this quantity by tap water TDS. (X - Y) ÷ X
6. Rejection = [(X - Y) ÷ X ] ×100
Important: Test the quality of the membrane once every 6 months.
Rejection of the RO Membrane Calculation Example
1. Tap water TDS = 150 ppm (X)
2. RO water TDS = 15 ppm (Y)
3. X - Y = 135 ppm
4. (X - Y) ÷ X = 135 ÷ 150 = 0.90
5. Rejection = [ ( X - Y) ÷ X ] ×100 = 0.90 ×100 = 90%
NOTE: Rejection rates less than 95% may indicate that the membrane should be
replaced.
SpectraPure
sales@spectrapure.com
Inc .
®
Fax 480.894.6109 Fax us toll-free 1.877.527.7873
®
Meter shown with switch set to
"IN" position. Slide switch to right
for "OUT" position.
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