HI98331 Hanna Instruments GroLine Soil Test - Direct soil EC and temperature measurer
Hanna Instruments GroLine Soil Test HI98331 is a portable meter that measures the electrical conductivity (EC) and temperature directly in soil. It is intended for growers, horticulture professionals, greenhouse operators and other users who need to monitor soil conditions as part of plant care and cultivation.
Conductivity is the ability of a material or solution to allow an electrical current to flow through it. In soil testing, EC can give an indication of the presence of dissolved salts and ions, including those from fertilizers. Thus the measurement of soil conductivity can provide useful information for the change of the growing environment. However, EC does not identify individual nutrients or their precise concentrations.
The HI98331 is a compact handheld meter for conductivity and temperature measurement. A stainless steel internal penetration probe allows direct measurement in wet soil without the need to first extract a sample and prepare a separate liquid solution.
How does HI98331 measure the conductivity of soil
The meter employs a non-removable stainless steel penetration probe of 114 mm length. When placed in suitably moist soil, the probe measures the electrical conductivity in its measurement range. The instrument also measures temperature, so that temperature-dependent changes in conductivity readings can be compensated for automatically.
The HI98331 measures EC from 0 to 4000 µS/cm (0.00 to 4.00 mS/cm or dS/m). The range is for direct testing of soil conductivity. The instrument does not measure pH nor directly measure individual nutrients.
Main characteristics and practical uses
- Direct soil measurement: The penetration probe allows conductivity readings to be made directly in soil, minimizing the need to prepare samples for testing.
- Stainless steel probe: The 114 mm probe is designed to penetrate moist soil as a reading is taken.
- Automatic temperature compensation: A fixed temperature coefficient of 2%/°C compensates for temperature-dependent variations in conductivity measurements.
- Automatic 1 point calibration: The meter automatically calibrates with 1.41 mS/cm conductivity standard.
- Single-button operation: The simple controls make the instrument perfect for routine measurements in the greenhouse, garden or field.
- Compact hand-held design: Only about 74 g, the meter is light enough for frequent use in many testing locations.
- Automatic shut-off options: The meter shuts off after 8 or 60 minutes of non-use or the automatic shut-off can be turned off.
Technical specs
- Brand Name: Hanna Instruments
- GroLine Soil Test Product Line
- HI98331II
- Product type: EC and temperature meter for direct soil
- EC measuring range: 0-4000 µS/cm; 0.00-4.00 mS/cm (dS/m)
- EC resolution: 1 µS/cm; 0.01 mS/cm (dS/m)
- EC accuracy at 25 °C: 0-2000 µS/cm: ±50 µS/cm 2000-4000 µS/cm: ±300 µS/cm
- EC accuracy mS/cm 0.00-2.00 mS/cm ±0.05 mS/cm 2.00-4.00 mS/cm ±0.30 mS/cm
- Calibration: Automatic, 1 point, 1.41 mS/cm
- Temperature: 0.0 to 50.0 °C (32.0 to 122.0 °F)
- Temperature resolution: 0.1 °C/ °F
- Temperature Accuracy: ±1.0°C (±1.5°F)
- Temperature compensation: Automatic, with a fixed coefficient of 2%/°C
- Probe: 114 mm (4.5 in.) stainless steel penetration probe (fixed)
- Battery type: CR2032 Lithium coin cell
- Battery life: Up to 100 hours of continuous use
- Automatic shut-off 8 minutes 60 minutes Disabled
- Operating environment: 0-50 °C, max. relative humidity 95 %
- Dimensions: 50 x 196 x 21 mm
- Weight: Approx. 74 g
Applications and compatibility suitable
The HI98331 is ideal for direct measurement of soil conductivity in a wide variety of growing conditions.
- Greenhouses: Compare conductivity readings between different growing areas.
- Agriculture and Horticulture: Regular monitoring of soil conductivity for crop management.
- Gardens and growing beds: Look for differences between locations or over time in conductivity.
- Soil research: Collect conductivity and temperature measurements for comparison with suitable soil samples and testing locations.
EC readings should be viewed in relation to the soil type, its moisture level, the amount of fertilizer being used and the crop requirements. A high or low reading alone does not indicate if the soil has the proper balance of nutrients.
How to use the gage
Choose a good site for testing . The soil should be moist enough to allow direct measurement . If necessary, drill a hole with a suitable tool so that the probe can be inserted repeatedly without much force. Before taking a reading, clean the probe according to the manufacturer’s instructions.
Insert the probe into the soil and wait for the reading to stabilize before taking it. Use similar sampling locations and conditions for comparisons across time, when possible. The readings can be influenced by moisture, soil composition and the positioning of the probe.
The HI98331 needs to be calibrated using the 1.41 mS/cm conductivity standard as described in the manual. After use keep the probe clean. When not in use, store the instrument in its protective sleeve.
Components included
The HI98331 is delivered with:
- HI73331 Stainless steel conductivity penetration probe
- CR2032 battery
- Protection sleeve & storage
- Calibrated screw-driver
- User Manual
- Certificate of instrument quality
Verify the contents of the particular kit being delivered against the packaging information provided by the supplier.
Main limitations
The HI98331 measures electrical conductivity and temperature directly in the soil. It does not measure pH, identify individual dissolved ions, or give a direct analysis of specific nutrient concentrations. If such measurements are required, additional instruments or laboratory tests are needed.
The soil should be moist enough to give consistent results, and measurements should be taken under similar conditions. The instrument is intended to be used in the above temperature and conductivity ranges. To ensure reliable measurements, it is recommended to clean and store the device according to the manufacturer’s calibration instructions.
