Introduction
The Meascom HHT-DO200 portable dissolved oxygen meter is designed for accurate measurement of dissolved oxygen in water. The instrument measures dissolved oxygen concentration and temperature, while allowing users to enter salinity and atmospheric pressure values to improve measurement accuracy.
Proper calibration and compensation settings ensure reliable results when testing natural waters, aquaculture systems, ponds or environmental samples.
Parameters Measured
| Parameter | Description |
|---|---|
| Dissolved Oxygen | Measures oxygen available in water for fish and aquatic organisms |
| Temperature | Automatically measured by the probe |
| Salinity | Entered manually to compensate dissolved oxygen readings |
| Atmospheric Pressure | Entered manually for improved measurement accuracy |
Dissolved oxygen solubility changes with temperature, salinity and atmospheric pressure, which is why compensation settings are important for accurate results.
Preparing the Instrument
Before measuring dissolved oxygen:
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Inspect the DO probe membrane for damage or air bubbles.
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Ensure the probe contains fresh electrolyte solution.
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Turn on the meter and allow the probe to stabilise.
If the membrane appears damaged or the electrolyte is contaminated, replace the membrane cap before use.
Setting Compensation Values
For accurate measurements, enter the appropriate environmental values.
Salinity Compensation
If measuring seawater or brackish water, enter the salinity value in ppt (parts per thousand).
Freshwater typically has a salinity close to 0 ppt.
Atmospheric Pressure
Atmospheric pressure affects oxygen solubility. Enter the local pressure value or use the approximate value for your location.
Calibration Procedure
Calibration ensures the meter provides accurate dissolved oxygen readings.
Typical calibration steps:
- Moisten the probe sponge in the calibration chamber.
- Insert the probe into the chamber.
- Allow the probe to stabilise in air-saturated conditions.
- Perform the calibration function on the meter.
- The meter will automatically calculate the correct dissolved oxygen value based on temperature and entered compensation values.
Measuring Dissolved Oxygen
- Rinse the probe with clean water.
- Immerse the probe in the sample.
- Gently stir or move the probe to ensure fresh water contacts the membrane.
- Wait for the reading to stabilise.
Record the dissolved oxygen value in mg/L or percent saturation.
Maintenance Tips
Proper maintenance improves probe life and measurement reliability.
Recommended practices:
- Keep the probe membrane clean
- Replace electrolyte periodically
- Store the probe according to manufacturer recommendations
- Avoid touching the membrane surface
Membrane caps and electrolyte should be replaced when readings become unstable or slow to respond.
Typical Applications
The HHT-DO200 dissolved oxygen meter can be used in:
- aquaculture ponds
- environmental water monitoring
- wastewater treatment
- lakes and rivers
- laboratory testing
Summary
The Meascom HHT-DO200 dissolved oxygen meter provides reliable measurement of dissolved oxygen and temperature. By entering appropriate salinity and atmospheric pressure values and performing regular calibration, users can obtain accurate water quality measurements in a wide range of environments.
