The HI98131 GroLine Combo offers high accuracy pH, EC (conductivity), TDS
(total dissolved solids), and temperature measurements in a rugged, waterproof casing that floats.
The GroLine Combo features a replaceable pH electrode with extendable cloth junction as well as an EC/TDS graphite electrode.
The renewable cloth junction provides an extended electrode life and the replaceable pH cartridge means that this tester does not need to be thrown away when the pH sensor is exhausted.
The EC/TDS conversion factor is user-selectable, as well as the temperature compensation coefficient (β).
- Designed to withstand the humidity of a growing environment
- Automatic one-point calibration using our Quick Cal solution
- Automatic Temperature Compensation
- All readings are compensated for variations in temperature
- Temperature displayed in °C or °F along with pH reading
- Measurement instability indicator
- Meter displays a clock tag that will disappear when the reading has achieved stability
- HOLD button
- Freezes reading on the display to allow recording of measurement
- BEPS (Battery Error Prevention System)
- Meter will automatically shuts off if there is not enough power to get an accurate measurement
- Battery % level at startup
- Low Battery Indicator
- Automatically shuts off after 8 or 60 minutes of non-use to maximize battery life
Calibrate pH and EC with one solution
Calibration of both pH and EC can be performed using our Quick Cal calibration solution
A pocket clip is featured on the back of the the GroLine Combo
Supplied with all the tools necessary to start performing tests
High accuracy EC/TDS graphite probe
The graphite conductivity probe provides greater accuracy because it cannot be contaminated by salt deposits in the solution.The exposed temperature sensor provides fast response times and guarantees highly accurate temperature compensated readings.
Replaceable pH electrode cartridge
The Combo features an easy-to-replace pH electrode.The sturdy, snap-in connector means there are no pins to bend or break.
Extendable cloth junction
Simply pull out 3 mm (1/8”) and cut when the cloth junction becomes dirty to improve response time and stability.
0.00 to 14.00 pH
automatic, one or two-point calibration (using pH 4.01, 7.01, 10.01 buffers); one-point calibration using HI5036 or HI50036 Quick Cal calibration solution
0.00 to 6.00 mS/cm
automatic, one-point at 1.41 mS/cm or 5.00 mS/cm; one-point calibration using Quick Cal calibration solution
automatic, with β = 1.9%/°C
0 to 3000 ppm (500 CF); 0 to 3999 ppm (700 CF)
10 ppm (mg/L)
0.5 (500 ppm) or 0.7 (700 ppm)
0.0 to 60.0°C / 32.0 to 140.0°F
0.1°C / 0.1°F
HI73127 (replaceable; included)
0 to 50°C (32 to 122°F); RH max 100%
Battery Type / Life
1.5V (4) / approx.100 hours of continuous use; auto-off after 8 min or 60 min of non-use; can be disabled
Dimensions / Weight
163 x 40 x 26 mm (6.4 x 1.6 x 1.0’’) / 100 g (3.5 oz.)
HI98131 (GroLine Combo) is supplied with HI73127 pH electrode, electrode removal tool, Quick Cal calibration solution sachets (4), electrode cleaning solution sachet, batteries, storage cap, quality certificate and instruction manual.