Wireless optical air & water oximeter sensor Redy

Quick Answer: The Redy wireless optical air and water oximeter is an optical oxygen sensor that measures oxygen both dissolved in water and in air, sending the readings wirelessly for logging. Despite the word oximeter, it is a laboratory and environmental sensor, not a pulse oximeter for blood oxygen.

How Optical Oxygen Sensing Works

Optical oxygen sensors generally use a spot or cap coated with a luminescent dye. Light excites the dye, and oxygen molecules quench its glow: the more oxygen present, the weaker and shorter-lived the luminescence. Unlike the older membrane electrodes of the Clark type, the method uses no electrolyte and does not consume oxygen, so readings in still water depend far less on stirring.

The title names both air and water. In water it works as a dissolved oxygen meter, reporting the oxygen available to fish, invertebrates and plants; in air it tracks the oxygen fraction inside a closed chamber. That double role suits biology practicals in which pondweed or a yeast suspension changes the oxygen level in a sealed vessel. The listing does not give the range, the units shown or whether the sensing cap can be replaced.

For gas-phase work only, the separate wireless air oximeter sensor measures oxygen in air.

Specifications

Applications

• Measuring oxygen released by pondweed at different light intensities
• Following oxygen use by germinating seeds or yeast in a sealed chamber
• Comparing dissolved oxygen in tap water, aquarium water and river samples
• Showing how dissolved oxygen falls as water temperature rises
• Estimating biochemical oxygen demand from samples measured before and after incubation

Care & Handling

• Protect the optical sensing surface from scratches, fingerprints and long exposure to strong sunlight.
• Rinse with clean water after each sample and store the sensor as the maker recommends.
• Calibrate against air, or air-saturated water, before each session.
• Allow the reading to settle when moving between air and water or between samples at different temperatures.

Why Choose LabEquip

Biology and environmental science teachers who want one oxygen sensor for both aquatic and gas-phase practicals are the natural buyers. It appears in LabEquip’s chemistry lab equipment range; range and sensing-cap questions are welcome through the contact page.

Frequently Asked Questions

Is this a pulse oximeter?

No. A pulse oximeter clips to a finger and estimates blood oxygen saturation. This sensor measures oxygen in water and in air for experiments and must not be used for any medical purpose.

What is the advantage of an optical oxygen sensor over a membrane electrode?

Optical sensors generally need no electrolyte refills or membrane changes, do not consume oxygen as they measure, and are less affected by how fast the water moves past them. Membrane electrodes need more upkeep and steady stirring.

Why does dissolved oxygen change with temperature?

Oxygen is less soluble in warm water than in cold, so a warm sample holds less oxygen even when fully saturated. Record the temperature with each reading so results can be compared fairly.

How is the sensor calibrated?

Commonly by exposing it to air, or to water saturated with air, which gives a known oxygen reference, and sometimes to an oxygen-free solution for the zero point. Follow the calibration steps in the software.

Can it be used in seawater?

Salt lowers the solubility of oxygen, so readings in seawater need a salinity correction if the software offers one. Rinse the sensor well in fresh water afterwards.

How long does a reading take to stabilise?

Allow time after placing it in a new sample, especially if the sample is warmer or colder than the last one. Wait until the logged value stops drifting before recording it.

Last Updated: September 2026