In-Line TDS Meter - Water Quality Tester
Measure the tap water coming in vs. the purified water going out of your water filtration system at any time.
- Displays total dissolved solids (TDS) levels of the feed water and product water with in and out electrode probes
- Highly efficient and accurate due to its advanced microprocessor technology
- Auto-Off function conserves battery power. The unit shuts off automatically after 10 minutes of non-use
- Dual Range 0-9990 ppm (the resolution is 1 ppm. From 1000 to 9990 ppm, the resolution is 10 ppm, indicated by a blinking 'x10' image)
- Factory Calibrated with a 342 ppm NaCl solution. Meters can be recalibrated with a mini-screwdriver
- Comes equipped with Quick-Connect T-fittings
- Installs quickly and easily
Specifications
- Operating range: 0 to 9990 parts per million (ppm)
- Accuracy: ±2%
- Conversion Factor: NaCl (avg. 0.5)
- Cable Length: 24.5" (including sensor)
- Fittings: 1/4" standard, also available with 3/8"
- Power Source: 2 x 1.5V button cell batteries (included)
- Battery Life: approximately 1000 hours of continuous use
- Dimensions: 3" x 0.8" x 1.9"
- Weight: 2.8 oz.
Calculate Rejection Rate
A TDS meter is a great tool for calculating the effectiveness of your reverse osmosis system by measuring the total dissolved solids (TDS) content of your water both before and after the reverse osmosis system. You can also use these readings to tell you when the membrane needs to be changed.
The filtered water's TDS reading should be within 3-10% of your tap water's TDS reading. This is a normal range. You should test your water once or twice a year to monitor your RO membrane condition. When your filtered water's TDS readings increase to 15-20% of your tap water's TDS reading, then it is time to replace your membrane.
Once you have obtained the TDS levels of your tap water (IN) and filtered water (OUT), use the calculator below to determine the rejection rate of your reverse osmosis system.

