pH/mV Meter Automatic Calibration, ATC, Microprocessor


The HI8424 is a compact, waterproof, portable pH/mV/temperature meter that is supplied complete with a protective carrying case, PEI plastic body pH electrode, stainless steel temperature probe, calibration buffer sachets, and cleaning solution sachets. The meter features automatic calibration at one or two points as well as Automatic Temperature Compensation (ATC) when the temperature probe is connected.
  • Compact waterproof design
  • Automatic Temperature Compensation (ATC)
  • Automatic one or two-point calibration

The HI8424 is an economical portable pH/ mV meter. This meter uses a BNC connector for the pH electrode input allowing for a wide selection of pH and ORP electrodes to be used. A separate temperature probe is supplied to provide temperature compensated pH measurement. The HI8424 is very basic in operation with automatic calibration to one or two points to any of the three programmed buffer values (pH 4.01, 7.01, and 10.01). The simplicity in operation and the economical price point has made the HI8424 one of the most popular meters available in the market.

Low Battery Indicator - A low battery indicator will be displayed when the battery life is almost exhausted (5% remaining) alerting the user that a new battery will be needed in the near future.

Automatic Shutoff - The automatic shutoff feature will turn the meter off after 20 minutes to conserve battery life.

High Resolution/Accuracy mV Range - The HI8424 automatically switches resolution from 1 mV to 0.1 mV when ORP readings are between -699.9 to +699.9 mV. The accuracy within this range is ±0.2 mV.

Automatic Temperature Compensation - Separate temperature probe is supplied to provide temperature compensated measurements.

Automatic Calibration - calibration to one or two points to any of the three programmed buffer values (pH 4.01, 7.01, and 10.01).

Waterproof - Compact, heavy duty casing that is protected against any ingress of water that would damage the electronics.


pH Range -2.00 to 16.00 pH pH Resolution 0.01 pH pH Accuracy ±0.01 pH pH Calibration automatic, at one or two points with three standard buffers (4.01, 7.01,10.01) mV Range ±699.9 mV; ±1999 mV mV Resolution 0.1 mV; 1 mV mV Accuracy ±0.2 mV; ±1 mV Temperature Range -20.0 to 120.0°C / -4.0 to 248.0°F Temperature Resolution 0.1°C / 0.1°F Temperature Accuracy (@ 25°C/77°F) ±0.4°C; ±0.8°F Temperature Compensation automatic from -20.0 to 120.0ºC (-4.0 to 248.0ºF) or manual without temperature probe connected pH Electrode HI1230B PEI body pH probe with BNC connector and 1 m (3.3’) cable (included) Temperature Probe HI7662 stainless steel temperature probe with 1 m (3.3’) cable (included) Slope Calibration From 75 to 110% / ±1 pH Input Impedance 10¹² Ohms Battery Type / Life 9V / approximately 150 hours of continuous use; auto-off after 20 minutes of non-use (can be disabled) Environment 0 to 50°C (32 to 122°F); RH max 100% Dimensions 164 x 76 x 45 mm (6.5 x 3.0 x 1.8”) Weight 180 g (6.3oz.) Ordering Information HI8424 is supplied with HI1230B pH electrode, HI7662 temperature probe, HI70004 pH 4.01 buffer solution sachet, HI70007 pH 7.01 buffer solution sachet, HI700601 electrode cleaning solution sachets (2), battery, protective case and instructions.