Question 19 of 30
Operating Principle of the Infrared instrument: identify the key principle that leads to detection of hydrocarbon gas,
A
The infra-red (IR) sensor is a transducer for the measurement of the concentration of hydrocarbons by the absorption of infra-red radiation.
B
The vapor to be monitored reaches the measuring chamber by diffusion or by means of a pump.
C
An infrared source illuminates a volume of gas that has entered inside the measurement chamber.
D
The gas absorbs some of the infrared wavelengths as the light passes through it, while others pass through it completely unattenuated.
Advertisement
Answer & Explanation
The correct answer is Option D: The gas absorbs some of the infrared wavelengths as the light passes through it, while others pass through it completely unattenuated..
Infrared (IR) sensors work by measuring the absorption of specific infrared light wavelengths as they pass through the gas. Hydrocarbons absorb specific IR frequencies, allowing the concentration to be calculated.