Combo Gro’chek pH/TDS/Temperature (Low Range) Meter - HI991404

SKU: HI991404-01


The HI991404 has been engineered to continuously monitor pH, TDS (0 to 2000 ppm) or EC (0 to 3999 µS/cm) and temperature. This microprocessor based meter feature a large, dual level, backlit LCD to give instantaneous readings of pH, EC or TDS and temperature. Optimized for hydroponic and greenhouse applications, the meter housing and cable connections have been sealed against vapor and humidity and all the necessary measuring probes are supplied with purchase.

  • Waterproof
  • Automatic Temperature Compensation (ATC)
  • Large, backlit LCD screens for easy reading

The HI991404 is a simple way to measure pH, TDS (0 to 2000 ppm) or EC (0 to 3999 µS/cm) and temperature. Installation is easy; simply hang the meter right above the sample to be tested for continuous measurement, plug the instrument to the mains, immerse the probes and the unit will run without interruption on 12 VDC power supply. The large, dual-display LCD screens show pH, TDS or EC and temperature readings simultaneously. Designed for use in greenhouses and horticultural applications, this meter is waterproof and protected against the ingress of dust and particles.

The meter is supplied with a HI1293D pre-amplified pH electrode with a PEI body and DIN connector. The amplifier for the pH electrode prevents interference from humidity and sources of electrical noise include circulating pumps, motors, and ballasts for grow lights. The polyethylenimine (PEI) protective body protects against most aggressive chemicals as seen in fertilizer solutions with high concentrations of phosphate and nitrate.

The fixed conductivity probe, HI7630 2-pin amperometric features a built-in temperature sensor, 2m (6.6’) cable and protective sleeve to resist most aggressive chemicals.Calibration and temperature compensation are automatic, while the EC/TDS conversion factor and temperature coefficient (β) are user adjustable for application specific measurements. Additionally, both the HI1293D pH electrode and HI7630 conductivity probe have been molded with pipe thread (1/2’’ NPT), which allows the user to attach them to an in-line system.

Features at a Glance

Large, dual-level LCD screen

    • Easily see pH, TDS or EC and temperature readings even in low light

Automatic one-point or two-point calibration

    • Automatically calibrate to 1 or 2 points with auto-buffer recognition


Automatic Temperature Compensation

  • Samples automatically compensated for temperature variations

Adjustable TDS Factor

  • TDS factor adjustable from 0.45 to 1.00 for application specific measurements




More Information
SKU HI991404-01
Product Name Combo Gro’chek pH/TDS/Temperature (Low Range) Meter - HI991404
Quote Required No
pH Range 0.0 to 14.0 pH
pH Resolution 0.1 pH
pH Accuracy ±0.1 pH
pH Calibration Automatic, 1 or 2 point with auto-buffer recognition
EC Range 0 to 3999 µS/cm
EC Resolution 1 µS/cm
EC Accuracy ±2% F.S.
EC Calibration Automatic, 1 point at 1413 µS/cm
TDS Range 0 to 2000 ppm
TDS Resolution 1 ppm
TDS Accuracy ±2% F.S.
TDS Calibration Automatic, 1 point at 1382 ppm
EC/TDS Temperature Compensation Automatic, with β adjustable from 0.0 to 2.4%/ºC
EC to TDS Conversion Factor Adjustable from 0.45 to 1.00 (CONV)
Temperature Range 0.0 to 60.0°C / 32.0 to 122.0°F
Temperature Resolution 0.1°C / 0.1°F
pH Electrode HI 1293D pH electrode (included)
EC/TDS Probe HI 7630 conductivity probe (fixed)
Power Supply 12 VDC adapter (included)
Environment 0 to 50ºC (32 to 122ºF); RH max 95% non-condensing
Dimensions 160 x 105 x 31 mm (6.2x4.1x1.2’’)
Weight 190 g (6.7 oz.)
Ordering Information HI991404 is supplied with HI1293D pH electrode, HI7630 fixed EC probe, pH 4 sachet (20 mL) (1), pH 7 buffer sachet (20 mL) (1), 1413 µS/cm calibration solution (20 mL) (1), HI700661 cleaning solution sachet (2), 12 VDC power adapter and instruction manual.
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