â·ÃÊͺ¶ÒÁÃÒ¤Ò SM-1: In-Line Single TDS Monitor Ideal for any water filtration system, including reverse osmosis systems, coolers and much more. SM-1: In-Line Single TDS Monitor Ideal for any water filtration system, including reverse osmosis systems, coolers and much more. FEATURES Displays TDS level of a single water line. 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. Wide Range 0-9990 ppm (From 0 - 999 ppm the resolution is 1 ppm. From 1000 to 9990 ppm, the resolution is 10 ppm, indicated by a blinking 'x10' image.) Factory Calibrated: our meters are calibrated with a 342 ppm NaCl solution. Meters can be recalibrated with a mini-screwdriver. Comes equipped with Mur-lok® Quick-Connect T-fitting (1/4 inch standard, also available in 3/8" or 1/2" ). Installs quickly and easily. SPECIFICATIONS Range: 0-9990 ppm Accuracy: ±2% Conversion Factor: NaCl (avg. 0.5) Cable Length: 24.5" (including sensor) Fittings: 1/4" standard, also available with 3/8" or 1/2" Power source: 2 x 1.5V button cell batteries (included) Battery life: approx. 1000 hours of continuous use Size: 7.6 x 2 x 4.7 cm (3 x .8 x 1.9 in.) Weight: 79.4 g (2.8 oz.) HM Digital SM-1 TDS Meter Total Dissolved Solid Meter à¤Ã×èͧÇÑ´¤èÒ TDS à¤Ã×èͧÇÑ´µÐ¡Í¹