If you are looking for a meter to test ORP, we recommend purchasing the HM Digital ORP-200 for better performance.

Features:

• High accuracy pH and ORP measurements
• Waterproof combo has a large easy-to-read, dual-level LCD and automatically shuts-off
• ORP and pH readings automatically compensate for the effects of temperature (ATC).
• Tester has a greatly extended life:
• Replaceable pH electrode cartridge with an extendable cloth junction

Specifications:
Range:

• pH: -2.00 to 16.00 pH
• mV: +/-1000 mV
• Temp: -5.0 to 60.0°C / 23 to 140.0°F

Resolution:

• pH: 0.01 pH
• mV: 1 mV
• Temp: 0.1°C / 0.1°F

Accuracy:

• pH: ±0.05 pH
• mV: +/-2 mV
• Temp: ±0.5°C / ±1°F
• Temperature compensation: pH; automatic

Calibration:

• pH: Automatic, 1 or 2 points with 2 sets of memorized buffers
• (pH 4.01 / 7.01 / 10.01 or 4.01 / 6.86 / 9.18)
• pH Electrode: HI 73127 (replaceable; included)
• Environment: 0 to 50°C (32 to 122°F); RH max 100%
• Battery type / life: 4 x 1.5V / approx. 100 hrs of continuous use; auto-off after 8 mins of non-use
• Dimensions: 163 x 40 x 26 mm (6.4 x 1.6 x 1.0")
• Weight: 100 g (3.5 oz.)