Based on the principle that different gases have different heat conduction capabilities, it can estimate the content of certain components by measuring the thermal conductivity of the mixed gas.
This kind of analytical instrument is simple and reliable, and it is applicable to many types of gas. It is a basic analytical instrument. However, it is difficult to directly measure the thermal conductivity of a gas, so in practice, the transformation of the thermal conductivity of a gas is often converted into the transformation of resistance, and then measured by an electric bridge.
The thermally sensitive parts of the thermal conductivity type gas analyzer mainly include semiconductor sensitive parts and metal resistance wires. Semiconductor sensitive components have small volume, small thermal inertia, and large temperature coefficient of resistance, so they have high sensitivity and small time lag. On the platinum coil, a bead-shaped metal oxide is sintered as a sensitive component, and the same platinum coil with the same internal resistance and heat generation is wound as a compensation component. The two parts form a bridge circuit as two arms, that is, a measurement circuit. When the semiconductor metal oxide sensitive component adsorbs the measured gas, the electrical conductivity and thermal conductivity change, and the heat dissipation state of the component changes accordingly.
The temperature change of the component changes the resistance of the platinum coil, and the bridge has an unbalanced voltage output, which can detect the gas concentration.
Thermal conductivity gas analyzer has a wide range of applications. In addition to commonly used to analyze the content of hydrogen, ammonia, carbon dioxide, sulfur dioxide and low concentrations of flammable gases, it can also be used as a detector in a chromatograph to analyze other components.
View more oxygen analyzers at www.avcray.com.
