Digital Handheld Pocket TDS Meter

Digital handheld pocket TDS meter for testing reverse osmosis membrane performance

The HM Digital TDS-EZ handheld TDS water quality tester accurately measure the TDS (Total Dissolved Solids) level in your water. This handy tool is ideal for testing reverse osmosis membrane performance. It lets you determine how good or bad your water is and whether it’s time to replace your reverse osmosis membrane. This digital handheld pocket TDS meter works for water purification applications, waste water regulation, aquaculture, hydroponics, and colloidal silver. It’s great for both consumer or commercial use. The NSF minimum standard for percent rejection is 75%. We recommend replacing your reverse osmosis membrane once it tests at 80% rejection or lower.

• Easy to use
• Highly efficient and accurate due to its advanced microprocessor technology
• Large and easy-to-read LCD screen
• Hold function: Saves measurements for convenient reading and recording, with the sound of a buzzer
• Auto-off function: Turns off meter after 10 minutes of non-use to conserve batteries
• Automatic function: After operating three minutes in the same condition, the measurement simply stops
• In case of measuring over 999ppm (high TDS reading), the figure of “X 10” lights up
• Recalibration is not necessary, but can be done easily with a watch screwdriver

Using a clean cup or glass, take a sample of your raw feed water. Remove the protective cap from the TDS meter. Push the “ON” button to activate LCD display. Submerge the tester’s probes in the water sample and observe for about 10 seconds. Record the results.

Repeat the same procedure with a sample of your reverse osmosis (RO) water. Please note that if the reverse osmosis system is new or the membrane has just been replaced, do not test the first tank of RO water. The first tank of product water will contain sanitizer and possibly carbon fibers from your new filters. This will cause false reading.

Use the following formula to calculate the percentage of solids (TDS) that your membrane is removing:

[ (A – B) / A] x 100

A = Tap TDS reading

B= Reverse Osmosis TDS reading

For example,
If the tap TDS reading is 250 ppm, and the RO TDS reading is 65 ppm, then [(250 – 65) / 250] x 100= 74% (You’d want to replace your RO membrane)

If the tap TDS reading is 250 ppm, and the RO TDS reading is 10 ppm, then [(250 – 10) / 250] x 100= 96% (Your reverse osmosis system is working fine