Minimizing Hazards through Gas Measurement Instruments

 Trace gases in the atmosphere are known to be sources of photochemical smog, global warming, climate change, ozone depletion and acid rain. To quantify, understand and control these problems, highly sensitive gas measurement instruments are required. Different kinds of gas measurement instruments are produced to measure trace gases both on the ground and on air. In industries, whether it is the chemical, power and gas and oil industry, accurate gas measurements are of extreme importance since any inaccuracies can lead to poor quality of products, incorrect fiscal and allocation measurements, unsafe processes that can lead to facility damage and an unsafe environment for workers and potentially disastrous results.

The technology of gas measurement instruments

A gas detector measures and indicates the concentration of certain gases in the air using different technologies. The portable battery operated models are typically employed for safety reasons and to prevent toxic exposure and fire. Once the equipment measures high levels of gases, a series of audible and visible indicators like alarms, lights or a combination of signals will provide warning to workers. While of the old and standard gas measurement instruments were fabricated to detect one gas at a time, modern devices are now capable of detecting several gases at once. As the detectors measure a specified gas concentration, the sensor response serves as the reference point or scale. Once the sensor responses surpass a pre-set level, the alarms will activate to warn the users.

Classifications of gas detectors

Gas detectors are classified according to the type of gas that is measured: toxic or combustible. Although these gas measurement instruments are essential for home application, they are also employed in numerous industries like nuclear plants to detect combustible gases. These instruments are also used in wastewater treatment facilities to detect hazardous gases that can have a negative effect to the immediate environment.

Measurement of toxic gases

  • Electrochemical sensors – typically used to sense toxic gases like carbon monoxide, chlorine and nitrogen oxides. Generally, these kinds of detectors are highly sensitive and will give warning signals when toxic levels are present.
  • Metal oxide semiconductors – used for detecting toxic gases, more common of which is carbon monoxide, and work through a gas sensitive film that is composed of either tin or tungsten oxide. The sensitive film reacts with gases, triggering the device when toxic levels are detected. Generally, these kinds of gas measurement instruments are considered efficient due to their ability to operate in low-humidity ranges.

Measurement of combustible gases

  • Catalytic sensors – detects combustible gases like hydrocarbon and works through catalytic oxidation. The sensors are typically constructed from platinum treated wire coil. When the combustible gas comes in contact with the catalytic surface, it is oxidized and the wiring resistance is changed by heat that is released.
  • Infrared sensors or IR detectors – works through a system of transmitters and receivers to detect combustible gases particularly the hydrocarbon vapors. If gas is present in the optical path, it will interfere with light transmission between the transmitter and receiver. The altered state of light will determine the type of gas present. 

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