Gas detector Sensor Principles. Types of gas Sensors.

Gas detection guide FULL

Gas detection is one of the most important safety concerns in the Oil & Gas, Chemical & Pharmaceutical,  Marine and other applications. Gas detectors are electronic devices (gas sensors) that can detect and different types of flammable and toxic gasses. Gas Detectors can be fixed and portable or transportable. Usually, fixed Gas detectors are permanently installed in a chosen location and providing continuous monitoring of flammable gases concentration in the air. A portable Gas detectors usually are a small and handheld devices that can be used for monitoring an atmosphere in a limited space. Gas detectors tracing leaks to give an early warning of the presence of flammable or toxic gases.

Qualified selection and use of Gas detectors is the key factor in process safety.

Gas detector Sensor Principles. Types of gas Sensors.

Gas sensor

Catalytic Combustion Method Sensor

This sensor detects gas based on heat generated by combustible gas burning on an oxidation catalyst. It is the most widely used gas sensor designed specifically for combustible gases.
Gas sensor

New Ceramic Catalytic Method Sensor

This sensor uses a ultra-atomized oxidant catalyst (a new ceramic) to detect gas in a wide range of concentrations from a low level (ppm) to the lower-explosion-limit (LEL). It is an epoch-making sensor independently developed by us as a sensor designed specifically for combustible gas.

Gas sensor

Semi-Conductor Method Sensor

This sensor uses a metal oxide semiconductor, which changes in resistance when it comes into contact with a detectable gas. The sensor detects this change in resistance as the gas concentration. It is a general-purpose sensor that detects all type of gases ranging from toxic gases to combustible gases.

Gas sensor

Hot Wire Type Semi-Conductor Method Sensor

This sensor uses a metal oxide semiconductor, which changes in resistance when it comes into contact with a detectable gas. The sensor detects this change in resistance as the gas concentration. It is a high-sensitivity gas sensor for low concentrations

Gas sensor

Thermal Conductivity Method Sensor

This sensor detects the difference in thermal conductivity to determine the gas concentration. It is a proven combustible gas sensor that effectively detects high concentration gases

Potentiostatic Electrolysis Method Sensor

This sensor electrolyzes detectable gas using an electrode with the potential kept constant to allow a current to be generated, and then measures the current to determine the gas concentration. It is the gas sensor most suitable for detecting toxic gases. You can specify a particular potential to detect a particular gas.

Membrane-Separated Electrode Method Sensor

Based on the principles of the potentiostatic electrolysis-based sensor, this sensor is structured with a gas-permeable film (separating membrane) and an action electrode completely separated from each other. It is a toxic gas sensor with an excellent selectivity.

Membrane Type Galvanic Cell Method Sensor

This is a simple, traditional sensor based on the principles of cells. Requiring no external power supply, the sensor maintains stability over the long term.

Non-Dispersive Infrared Method Sensor

Based on the fact that many gases absorb infrared rays, this sensor applies infrared light to the measurement cell to detect changes in infrared light caused by the absorption of a detectable gas. It seamlessly detects all infrared light in a particular wavelength range without separating (dispersing) infrared light on a wavelength basis

Interferometer Method Sensor

This gas detector, one of the oldest gas sensors of ours, recognizes changes in the refractive index of gas. With a high accuracy, it maintains stability over the long term. In early times, it was used inside coal mines to measure the methane concentration and in recent years, it is widely used to measure solvent concentrations or heat quantities of fuel gases such as natural gas.

Chemical Tape Method Sensor

This sensor uses cellulose tape impregnated with a color former. It lets detectable gas enter this tape by allowing it to pass through it or diffuse into it. The sensor electrically measures reflected light based on the tape color caused by the reaction between the color former and detectable gas to quantitatively recognize a very low concentrations of toxic gas.

Photo-Ionization Detector

This gas sensor applies ultraviolet light to the detectable gas to ionize it. This causes an ion current to be generated. The sensor measures this current to determine the gas concentration. It detects a wide range of gases, irrespective of whether they are organic or inorganic. It is generally used to measure ppb to ppm levels of concentration of volatile organic compounds (VOCs

Pyrolysis-Particle Detection Method

This gas sensor heats the detectable gas to produce an oxide and measures particles of the oxide using a particle sensor. Maintaining stability over the long term, it exhibits an excellent interference resistance and responsiveness. The particle sensor is based on the same principles as for ionization-based smoke sensors that use radiation.

GAS DETECTION LIST

GAS detection list HAZOP EU

TYPICAL INTERFERENCE DATA

TYPICAL INTERFERENCE DATA

Gas detection Guide

Gas detection guide