Background: 

What is an Oxygen Detector? How do they work? Although there are many types of oxygen sensors, oxygen detectors can be classified in one of three ways:

1 A chemical reaction in which electrons are released in the presence of oxygen.
2. Changes in the intensity of light emitted by fluorescent materials when exposed to oxygen.
3. When oxygen passes through, the wavelength of sound, light or magnetic field changes.
Each of these methods of measuring oxygen has advantages and disadvantages. While oxygen sensors are used in many applications and industries, including automotive, health and medicine, industrial, food and beverage packaging, pharmaceuticals, and more, each application and industry uses a different type of oxygen sensor that is best suited for the application.

Note that most oxygen detectors are designed to measure oxygen from 0 to 25% by volume or in breathable air. However, specialized oxygen detectors that can measure up to 100% oxygen are also available.

Electrochemical Oxygen Detector

Electrochemical oxygen detectors are primarily used to measure oxygen levels in ambient air. They measure a chemical reaction within the sensor that produces an electrical output proportional to oxygen levels. Because electrochemical sensors generate an electric current, they are self-powered, which makes them useful for measuring oxygen cell-powered underwater diving and handheld personal safety devices. Examples include breathalyzers, breath sensors, and blood glucose sensors.

In terms of sensor advantages, electrochemical sensors are sought after for their low power requirements, lower detection limits, and are generally less directly affected by interfering gases. They also tend to be the cheapest sensors available.

A challenge with electrochemical oxygen sensors is their reliance on temperature-dependent chemical processes. The output of most electrochemical sensors will rely heavily on temperature compensation to provide reliable readings over a wide range of environmental conditions.

Another challenge with electrochemical oxygen sensors is that the chemical reaction slows down and stops over time, typically 1 to 3 years depending on the sensor design. Storing them in an oxygen-free environment will not extend the life of the sensor. As the sensor ages, it requires frequent recalibration and is not as accurate as other sensors.

Optical Oxygen Detector

The mechanism behind molecular oxygen fluorescence quenching has long been known. Certain molecules or compounds fluoresce (i.e. emit light energy) when exposed to light. However, if oxygen molecules are present, light energy is transferred to the oxygen molecules, resulting in a decrease in fluorescence. By using a known light source, the detected light energy is inversely proportional to the number of oxygen molecules in the sample. Therefore, the less fluorescent light is detected, the more oxygen molecules are in the sample gas.

In some sensors, fluorescence is detected twice at a known time interval. Instead of measuring total fluorescence, the decrease in luminescence over time (i.e., fluorescence quenching) is measured. This time-based approach to decay allows for simpler sensor designs.

An example of a sensor that measures ambient oxygen levels using oxygen fluorescence quenching. Although it has the same footprint as conventional electrochemical sensors, it does not absorb oxygen and has the advantage of a longer lifetime. This allows it to be used in devices such as indoor oxygen depletion safety alarms, which detect sudden drops in oxygen levels in compressed gas stored in the room air.

Common applications involving optical sensors include medical facilities, lasers, imaging systems, and fiber optics. Regarding sensor advantages, many people find that optical sensors have higher sensitivity, wider dynamic range, distributed configuration, and multiplexing capabilities.

Portable O2 gas detector

Portable O2 gas detector, have the chatactors of waterproof, dustproof, accurate detection data, sound and light alarm, long service life. The portable O2 detector can be used in indoor air detection, gas leakage, pharmaceutical factories and other scenes.

For more oxygen detector equipment, please consult the manufacturer JXCT