Hanna® Instruments Portable pH/EC/TDS Meter — HI9813-51

Hanna HI9813-51 Portable pH/EC/TDS/Temperature Meter

The Hanna HI9813-51 is a ruggedized, handheld multiparameter meter built for agricultural, greenhouse, and hydroponic water quality testing. A single HI1285-51 probe measures pH, electrical conductivity (EC), total dissolved solids (TDS), and temperature at once, cutting down on the number of instruments needed for daily monitoring in active growing operations.

The large backlit LCD displays pH at 0.1 resolution with +/-0.1 accuracy, EC in 0.01 mS/cm increments, and TDS in 1 ppm steps, all automatically temperature-compensated using a 2%/C coefficient. A variable EC-to-TDS conversion factor adjusts from 0.56 to 0.78 ppm/uS/cm, accommodating different nutrient solution standards. Manual one-point calibration at pH 7.01 and at 1.41 mS/cm or 1500 ppm keeps the meter field-ready, while the pre-amplified, gel-filled pH electrode resists electrical noise common in powered grow environments.

Key Features & Benefits

• 4-in-1 Multiparameter Probe: Measures pH, EC, TDS, and temperature with one insertion, saving time and reducing probe handling.
• Automatic Temperature Compensation: Readings corrected in real time from 0-50C for consistent accuracy regardless of solution temperature.
• Pre-Amplified Electrode: Built-in amplification reduces electrical noise interference from HID lighting, ballasts, and other grow-room equipment.
• Water-Resistant Polypropylene Body: Withstands splashes and humid greenhouse environments during routine testing.
• 150+ Hour Battery Life: A single 9V battery powers extended field use without frequent replacements.

Who Should Use This

Hydroponic cultivators, greenhouse managers, and agronomists who need a fast, reliable, all-in-one water quality tool for daily nutrient solution checks in recirculating systems, reservoir management, and incoming water source testing.

Compatibility

Probe: HI1285-51 (included), an amplified pH/EC/TDS/temperature probe with an 8-pin DIN connector and 1-meter cable. Compatible with standard pH 7.01 buffer and 1.41 mS/cm or 1500 ppm calibration solutions.

Frequently Asked Questions

Can this meter be used in salt water or high-EC solutions?

The EC range tops out at 4.00 mS/cm, which suits most hydroponic nutrient solutions. It is not designed for high-salinity seawater measurement.

How often should I calibrate the HI9813-51?

Calibrate at least once per week under normal use, or any time readings seem inconsistent. Always calibrate again after replacing the probe or after extended storage.

Is the probe replaceable?

Yes -- the HI1285-51 probe connects via an 8-pin DIN connector. It can be replaced independently of the meter body once the electrode reaches the end of its service life.

Does the meter display all four parameters simultaneously?

The large LCD displays pH, EC, TDS, or temperature one at a time -- cycle through modes with the front-panel button. On-screen prompts indicate the active measurement mode as you switch.