Hanna Instruments HI991301 pH, EC, TDS and temperature Combo Meter (High range)
The Hanna Instruments HI991301 is a portable, waterproof Combo Meter that measures pH, electrical conductivity (EC), total dissolved solids (TDS) and temperature of suitable liquid samples. The handheld instrument combines four measurement functions into one device, enabling users to measure a number of important water and other aqueous solution properties without requiring separate meters.
The HI991301 is intended for applications needing a higher conductivity measuring range. Measures EC up to 20.00 mS/cm and TDS up to 10.00 ppt (g/L). This makes it useful for testing nutrient solutions, irrigation water, process water and other liquids with relatively high concentrations of dissolved ions.
HI991301 – Liquid Measurement
The meter comes with the HI12883 combination probe, which has sensors for pH, electrical conductivity, TDS and temperature. The probe connects to the instrument by a DIN connector. The cable is about 1 meter long.
pH is a measure of how acidic or alkaline a liquid is. The pH scale ranges from 0 to 14 . Under standard reference conditions a pH value below 7 is acidic , 7 is neutral and a value above 7 is alkaline . The pH meter uses an electrode that is sensitive to hydrogen-ion activity and converts the electrical output into a pH value.
Electrical conductivity (EC) is a measure of the ability of a liquid to conduct electricity. Dissolved ions such as those in mineral salts and nutrient solutions provide conductivity. EC is used to monitor changes in the concentration of dissolved ionic substances, but does not identify specific substances.
Total dissolved solids (TDS) is an estimate of the dissolved solids derived from a conductivity measurement and a conversion factor. This factor can be adjusted from 0.45 to 1.00 in increments of 0.01 with the HI991301. The selected factor affects the TDS result that is shown, so you should use the same settings if you want to compare measurements.
Temperature measurements bring another layer of context to the readings. The instrument automatically compensates for temperature effects during pH measurement and has selectable temperature compensation for EC and TDS measurements.
Main Features and Applications
- High range EC measurement: Measures conductivity from 0.00 to 20.00 mS/cm, making the instrument suitable for liquids with higher conductivity than those measured by the HI991300.
- High range TDS measurement: Measures TDS from 0.00 to 10.00 ppt. Readings are in grams per liter
- Automatic pH calibration: 1 or 2 point calibration with standard buffers or NIST buffer sets.
- Automatic EC/TDS calibration: One-point calibration is possible using the correct high-range conductivity or TDS standard.
- Selectable temperature compensation: Allows the EC/TDS temperature coefficient to be set between 0.0 and 2.4%/°C in 0.1% steps.
- Amplified combination electrode The probe contains a built-in amplifier to help minimize the effect of electrical noise on pH measurements.
- Renewable cloth junction: The probe features a renewable cloth junction that can be extended to expose a fresh section when the current junction gets clogged, which helps to bring back normal response.
- Water-resistant housing: The instrument is housed in an IP67-rated casing to protect against dust and water under conditions defined by that rating.
- Portable operation: Three AAA batteries give approx. 600 hours continuous use under the conditions stated by the manufacturer.
- Selectable auto shut-off: The meter can be set to switch off after 8 or 60 minutes of inactivity, or the function can be disabled.
Tech specs
- Brand: Hanna Instruments
- Model: HI991301
- Type: Portable pH/EC/TDS/Temperature Combo Meter
- pH measuring range: -2.00 to 16.00 pH or -2.0 to 16.0 pH (depending on resolution)
- pH resolution: 0.01 pH or 0.1 pH
- pH accuracy at 25°C ±0.02 pH or ±0.1 pH depending on resolution
- pH-mV range: ±825 mV
- pH-mV resolution: 1mV
- Accuracy pH-mV at 25°C: ±1mV
- EC range: 0.00 - 20.00 mS/cm
- EC Resolution : 0.01 mS/cm
- EC accuracy at 25°C: ±2% full scale
- TDS Measurement Range: 0.00 – 10.00 ppt (g/L)
- 0.01 ppt TDS resolution
- TDS Accuracy @25°C ±2% of full scale
- TDS conversion factor : Selectable 0.45 to 1.00 in steps of 0.01
- Operating temperature range -5.0 to 105.0 °C, probe dependent
- Temperature resolution 0.1 °C
- 25°C Accuracy of temperature: ±0.5°C
- pH calibration: Automatic, one or two-point calibration
- Calibration EC/TDS: 1 point, Automatic
- EC/TDS temperature compensation: coefficient configurable from 0.0 to 2.4 % / °C
- Probe included HI12883 pH/EC/TDS/temperature probe
- DIN connector for probe connection
- Length of probe cable: ~1 m
- Power supply: 3 x 1.5 AAA battery
- Battery life: approx. 600 hours continuous use
- Automatic shut-off: Selectable after 8 or 60 minutes or disabled
- Operating environment: 0 to 50 °C; max. 100% relative humidity
- Protection against housing: IP67
- Meter size: 154 mm x 63 mm x 30 mm
- Weight: Approximately 196 g with batteries
- Warranty: As per manufacturer’s standard – 2 years
Applications and Compatibility
The HI991301 can be used in any application where pH, conductivity, estimated dissolved solids and temperature provide useful information about a liquid sample.
Typical uses are:
- Hydroponics and Nutrient Solutions: Monitor changes in a prepared nutrient solution by checking pH and conductivity.
- Irrigation water: Compare pH, Conductivity of water sources used for irrigation.
- Water quality testing: Testing for selected water properties during routine monitoring.
- Industrial Processes: Monitor liquid samples where pH and conductivity are important process parameters.
- Environmental sampling: Make measurements on appropriate water samples for time comparison.
- Field and laboratory measurements: Routine measurements at different sites with a portable instrument.
HI991301 is the high range equivalent to the HI991300 from Hanna Instruments. HI991300 measures EC up to 3999 µS/cm and TDS up to 2000 ppm. HI991301 measures EC up to 20.00 mS/cm and TDS up to 10.00 ppt. The appropriate model depends on the expected conductivity and dissolved solids levels of the samples.
Calibration, use and maintenance
Prior to any measurements, check the probe and cable for damage and verify the probe is clean. Calibrate the pH function with appropriate fresh buffer solutions. Standard pH buffers are 4.01, 7.01 and 10.01 for the HI991301. The alternative NIST set is 4.01, 6.86 and 9.18.
For EC/TDS calibration, use the appropriate high range calibration solution that comes with this model. The HI991301 includes a conductivity standard of 12,880 µS/cm and a TDS standard of 6.44 g/L. Refer to the manufacturer’s instructions for the proper calibration procedure and conversion setting.
The manual states that the probe should be immersed in the sample and the readings allowed to stabilize. Rinse probe between samples to reduce cross-contamination. Cleaning and storage of the electrode with suitable solutions and as per the manufacturer’s recommended procedure. With proper care and regular calibration measurements are reliable.
Components included
The HI991301 package includes:
- HI991301 meter
- HI12883 pH/EC/TDS probe with integrated temperature sensor, DIN connector and approx. 1 m cable
- pH 4.01 Buffer Solution Packet
- pH 7.01 buffer solution sachets
- HI70030 Conductivity Calibration Solution 12,880 μS/cm, One Sachet
- HI70038 TDS calibrating solution 6.44 g/L - single sachet
- Two sachets of HI700601 electrode cleaning solution
- 100ml plastic cup
- 1.5V AAA alkaline batteries x 3
- Meter calibration certificate
- Calibration certificate for sensor
- Instructions manual
- Sturdy Carrying Case
