Semiconductor gas sensor with excellent low concentration gas detection
Ozone gas is strong oxidizer, and is used for sterilization in Gas and Water Purification Equipment. Due to global infection of COVID-19, and the scene of ozone utilization seems to be increased. On the other hand, the high concentration of ozone is toxic to human and animal body. Therefore it is essential to control the ozone concentration in the room while using the ozone generator. Nissha FIS's ozone sensor is a semiconductor type gas sensor that detects ozone of 0.1ppm or less, which is obvious odor for people, with high sensitivity. Sensor Module can be easily added into air conditioning equipments such as air purifiers and generators for monitoring ozone gas concentration for indoor use.
（Source: Journal of JWWA, Vol.53, No.11）
When the concentration of ozone exceeds 0.1 ppm, the obvious effects on human health are apparent.
NISSHA FIS's ozone sensor is a highly sensitive that detects ozone of low concentration below 0.25ppm (250ppb).
It can be used for monitoring the high concentration of ozone in workplaces such as water purification facilities and offices.
The ozone sensor from Nissha FIS is a semiconductor gas type, using ITO (indium tin composite oxide) as the sensing gas material. The semiconductor gas sensor detects gas using the redox reaction that occurs when a gas-sensitive thin film formed on an alumina substrate is heated by a heater.
The gas sensitivity characteristics of a semiconductor gas sensor are expressed as a change in sensor resistance (RS) to a change in gas concentration on a logarithmic graph. The sensor resistance value increases with increasing gas concentration. The ozone sensor detecta linearly to ozone below 1ppm.
Sensitivity of semiconductor type sensor could be changed with long-term use, however the change tends to shift to the more sensitive that detects lower concentrations of ozone. In other words, it is a characteristic change over time in a safe direction, so it can be used with peace of mind.
The gas-sensing material of the semiconductor gas sensor does not wear out with use. For this reason, gas sensors can have a long service life of 10 years. (The sensor module including electronics takes up to two years.)
Semiconductor type gas sensors can be competitive in cost compared to other types of gas sensors. In addition, power consumption can be lower because no ancillary parts, such as special light sources, are required.
We offer not only gas sensor element, but also sensor modules capable of measuring concentrations up to 250ppb.
The gas sensor element is available for monitoring ozone gas generation, and the sensor module is available for integration into your product or any application that require monitoring and control of ozone gas concentration.
Concentration control of ozone as a byproduct from various sterilization process such as plasma discharge. Many air purifiers come with a sanitizing function. There are various methods for sterilization. Plasma discharge treatment is one of most known method by releases electrons and ions that have an destroys the bacteria, viruses and allergens. This plasma discharge treatment produces ozone as a byproduct. The ozone sensor perform an active role in monitoring if concentration of by producted ozone has exceed the level.
The ozone sensor detects when the ozone concentration in the air emitted from the ozone generator is below the specified level, which contributes to ensuring safety. Low concentration ozone with safe level for human body is using to decomposes bacteria or source substance of oder in products for sterilization and deorderization.
Urban ozone as an air pollution includes ozone produced by the reaction of factory and automobile exhaust fumes with ultraviolet light in sunlight. Some air purifiers used in countries such as China, where air pollution is serious, have function to monitor concentration level of ozone detected by gas sensors, thereby sugesting people to close their windows.
High concentration of ozone is used in industrial ozonizers for sterilization cleaning of water pipes and medical equipment, and water treatment in water purification facilities. The ozone sensor from Nissha FIS is also used in the scene of safety management because of its easy integration into various measuring devices.
High concentration ozone is using in fumigatioin sterilization at medical facilities such as operating rooms for sterilization of equipments and whole rooms. The ozone generated for fumigation process is naturally decomposed after the process. Ozone sensors are used to verify if ozone concentration in the rooms have dropped to a sufficiently low concentration.