An oxygen meter measures the amount of oxygen in the water, liquid, or gas analyzed. Dissolved oxygen meters, such as those from Oakton instruments, specifically measure the oxygen dissolved in water. They are used in many applications, especially as related to water quality: monitoring rivers, water treatment plants and sewage treatment, and in biotechnical processes.
Keep these considerations in mind when choosing an oxygen meter:
- Submersible or BOD probes. Submersible probes are ideal for field use while the BOD probes, available for certain meters, are more appropriate for laboratory use.
- Waterproof housing. Meters range from indoor use, to splashproof, to submersible.
- Automatic barometric pressure compensation. The solubility of oxygen decreases with an increase in altitude (or reduction of atmospheric pressure). Some meters have a built-in barometer to make this adjustment automatically.
- Manual barometric pressure compensation. Meters allow you to enter the barometric pressure manually.
- Salinity adjustment. As the salinity of the solution increases, the solubility of oxygen decreases. Meters may allow the user to enter the salinity value of their liquid, then compensate accordingly.
- Temperature compensation. As the temperature of a solution increases, the oxygen solubility decreases. Meters may provide automatic temperature compensation to ensure accurate readings.
- Memory capabilities. Meters may store readings in memory for downloading to a computer or a recorder.
- Replaceable membranes/caps/modules. Replaceable membranes are generally more cost-effective but are more time-consuming. Membrane modules are ready-to-use but cost a little more.