Attaching the city gas which adds the sulfide odorant ill-smelling concentration supervisory manner

摘要

PURPOSE:To directly perform measurement (monitoring) while a sample is allowed to flow by measuring the concn. of the sulfide type smell imparting agent added to coal gas using a sulfide type smell sensor. CONSTITUTION:At the time of non-measurement, a valve 6b is closed and air is always allowed to flow to a measuring line 7 from a line 2. Only at the time of measurement, the valve 6b is opened and a valve 6a is closed and the sample gas from a line 1 is mixed with the air introduced from the line 2 through a line 6 within the range of detonation concn. or less to be allowed to flow to the measuring line 7. A smell sensor 9 has a property reduced in its electric resistance value when the concn. of sulfide (smell) is high and sends the electric signal corresponding to the concn. of sulfide (smell) in gas to be measured to a control apparatus 10. From this result, smell imparting concn. is cleared. Measurement is carried out at a definite time interval and, at the time of non-measurement, air is allowed to flow to the measuring line 7 to regenerate the smell sensor 9. By this constitution, a measuring cost is reduced and the accuracy of the sensor is enhanced.