Natural gas that is extracted from underground is odorless ,so it should be odorized with a characteristic odor to be detected when there is leakage from pipelines ,instruments ,…
Conventional equipment which is known for this purpose is named odorizer that add a strong smelling odorant ,usually THT, or mercaptan to natural gas.
Special proportion are required to add odorant to the natural gas. On the one hand ,safe and constant odor intensity is desired , but on the other hand , adding too much odorant must be avoided to prevent unnecessary and unpleasant smells. For this purpose , the volume pulses of a corrector are used which are proportional to the gas volume.
This ensures an absolutely constant odorant concentration which is independent of any variations in the gas flow rate.