TDS Meter|TDS tester| TDS pen Water quality tester SPECIFICATIONS: Range:0~9990ppm (mg/L) Accuracy: ±2%F.S Calibration:Factory Calibrated Temperature Compensation: Automatic Operating Temperature: 0~50°C Power source: 2×1.5v(button cell) size: 142X 25X15mm weight: 36g OPERATING INSTRUCTIONS 1.remove the protective cap. the ON/OFF button once out of the water. The tester will read "000” 3. Immerse the tester into the water no more than 2 inches. 4.wait for the display to stabilize. The tester automatically compensates for temperatures variations. Once the readout stabilizes(10-30seconds), press the HOLD button to view out of the water. the ON/OFF button again to turn off the tester. The tester will shut off automatically after 10 minutes of non-use. 6.after usage, shake off the water from your tester or wipe it with a tissue. Note: If the tester displays a flashing”X10”icon, multiply the reading by 10.