HI 991001 Hanna Instruments - Portable pH and Temperature Meter - Water Resistant
The Hanna Instruments HI991001 is a portable meter for measuring the pH and temperature of liquids. The device is intended for specialists checking the quality of liquids during production processes, environmental measurements and other applications requiring reliable measurements of pH.
The pH value indicates how acidic or basic a liquid is. A pH lower than 7 indicates an acidic liquid, pH 7 indicates a neutral liquid, and a pH higher than 7 indicates a basic liquid. The measurement can be used to follow changes in the composition of liquids. The pH value does not indicate which substances are present in the liquid or their concentrations.
The HI991001 combines both pH and temperature measurements in one portable instrument. The supplied HI12963 pH electrode has a titanium body with an integrated temperature sensor. The meter compensates for temperature influences in pH measurements thanks to the automatic temperature compensation. The water-resistant IP67 housing and two-button control make the device suitable for use in a variety of work environments.
How does the HI991001 measure temperature and pH?
The HI991001 measures the pH value of a liquid using a pH electrode. The electrode registers an electrical signal which is related to the activity of hydrogen ions. The meter converts this signal to a pH value, which is shown on the display.
At the same time, the integrated temperature sensor measures the temperature of the fluid. Both readings are displayed on the screen of the meter and automatic temperature compensation is applied to correct temperature dependent changes during pH measurement.
The pH-meter has a measuring range of -2.00 to 16.00 pH and can also display a pH-related millivolt signal for checking the electrode. The electrode and instrument support a range of temperatures over which the measurement is made.
The HI991001 does not measure the electrical conductivity (EC), total dissolved solids (TDS) or individual nutrients levels.
Key features and practical applications
- pH and temperature measurement: Temperature and pH values should be measured simultaneously to be able to evaluate the pH value against the temperature.
- Accuracy of pH measurement: The specified pH measurement accuracy is ±0.02 pH at 25 °C under the specified measuring conditions.
- Automatic calibration: The meter offers automatic calibration at one or two points using preset buffer solutions.
- Temperature compensation: Automatic temperature compensation helps take into account the effects of temperature on the pH measurement.
- HI12963 electrode: The supplied pH electrode has a titanium body with an integrated temperature sensor and a cable of approx. 1 m.
- Water-resistant housing: The IP67 classification protects the meter against dust and water under the conditions of this protection class.
- Electrode condition indicator: An indicator on the display helps the user monitor the condition of the electrode.
- Battery monitoring: The meter provides information about battery status and warns when the battery voltage is low.
- Adjustable automatic shut-off: The meter can be switched off automatically after 8 or 60 minutes of inactivity. This functionality can be disabled too.
- Portable: The compact instrument is intended for measurements at various locations and is delivered with a rugged transport case.
Technical specifications
- Brand name: Hanna Instruments
- Product Line: HI991001
- Product type: Portable pH/temperature meter
- pH measuring range: -2.00 to 16.00 pH; -2.0 to 16.0 pH
- pH resolution: 0.01 pH; 0.1 pH
- pH accuracy at 25 °C: ±0.02 pH; ±0.1 pH depending on the selected resolution
- pH calibration: Automatic one- or two-point calibration
- Calibration buffers: Standard pH 4.01, 7.01 and 10.01; NIST pH 4.01, 6.86 and 9.18
- mV measuring range: +/- 825 mV (pH-mV)
- 4 mV resolution: 4 mV
- mV accuracy: ±1 mV (pH-mV)
- Temperature range: -5.0 to 105.0 °C (23.0 to 221.0 °F), depending on the electrode
- Temperature resolution: 0.1 °C / 0.1 °F
- Temperature accuracy at 25°C: ±0.5°C to 60°C; ±1.0°C outside of this range
- Temperature control: automatic
- Electrode: HI12963 pH/temperature electrode with titanium body and built-in temperature sensor
- Electrode connector: Fast DIN connector
- Length of cable: approx. 1 m
- Battery type: 3 x 1.5 V AAA alkaline batteries
- Battery Life: 1400 hours continuous usage (according to product specs)
- Operating environment: 3 to 50 °C, up to 100% relative humidity
- Protection class: IP 67
- Dimensions: 154 x 63 x 30 mm
- Weight: Approx. 199 g (inc. batteries)
- Warranty: 2 years as per manufacturer
Applications & compatibility
The HI991001 is a professional pH and temperature meter.
- Galvanic baths: Check the pH value of liquids used in galvanic treatment processes.
- Wastewater: As part of the water quality checks, check the pH value and temperature.
- Pool and spa water: During maintenance and water quality measurements check the water pH level.
- Drinking water: Conduct pH measurements and temperature measurements as part of water quality controls.
- Environmental measurements: Collect pH and temperature data for checking and comparing liquid samples.
- Industrial processes: Follow changes in the pH of liquids during industrial operations.
The suitability of the meter depends on the composition and temperature of the liquid and on the requirements of the measurement process. The supplied electrode should be checked for suitability to the medium to be measured for specific applications.
Using the Meter
Check the meter, electrode and cable are in good condition before use. Connect the electrode HI12963 and prepare the solution in accordance with the requirements of the application. Ensure that the electrode is clean and suitable for the fluid being measured.
Calibrate the meter using the correct pH buffer solutions as per the manufacturer's instructions. Depending on the accuracy required, a one or two-point calibration can be performed. Use fresh buffer solutions to prevent contamination affecting the calibration.
Insert the electrode into the liquid and allow the reading to stabilize. The display of the meter shows the pH value and the temperature. When comparing measurements, take into account differences in temperature, composition of the liquid and the measuring conditions.
After use, rinse and clean the electrode according to the manufacturer’s instructions. If necessary, use suitable cleaning solutions and store the electrode according to the recommended storage procedure. Consult the manual for instructions regarding proper cleaning, calibration, and storage of the electrode.
Includes components
Hanna Instruments HI991001 is included:
- HI12963 pH and temperature probe, titanium body, with cable
- Sachet pH 4.01 buffer solution
- Buffer solution pH 7.01 in sachet
- HI700601 Electrode Cleaning Solution, Sachet
- Beaker 100 ml
- 3 x 1.5V AAA alkaline batteries
- Instrument’s certificate of quality
- Certificate of quality for electrodes
- Handbook
- Heavy suitcase
Verify the packaging and the supplier’s product information to ensure that you have received the set that you ordered. The precise design of the electrode connector can vary with the product generation.
Key limitations
The HI991001 measures temperature and pH. It does not measure EC, TDS or individual ions, nor does it give direct analysis of specific chemicals or nutrient concentrations.
The measurements depend on the condition of the electrode, the correct calibration, the composition of the liquid and the measuring conditions. Contamination or a worn-out electrode can affect the stability and accuracy of the measurements.
The meter is capable of measuring over a wide temperature range, but the attached electrode may limit the usable range. Therefore, check the specifications of the electrode before performing measurements at high or low temperatures.
The IP67 classification applies to the protection of the meter housing under specified conditions. Follow the manual for the use and maintenance of the meter and electrode, and avoid using the electrode in liquids to which it is not suitable.
