| 摘要 |
PURPOSE:To continuously measure the concn. of the gaseous component of the gas in a hermetically closed space, by always recirculating the gas in the hermetically closed space through a pipeline and measuring the concn. of the gas by a limit current type gas sensor. CONSTITUTION:When a vacuum pump 14 is started, the gas in a pack 10 is guided to an oxygen concn. measuring part 16 through a pipe 11 and returned to the pack 10 through a pipe 12 to be recirculated and the concn. of oxygen in the gas within the pack 10 is continuously measured by a limit current type oxygen sensor 1. The whole of the limit current type oxygen sensor 1 is heated and, when a voltage is applied between electrodes 3a, 3b, the oxygen molecule of the space SP1 in a cap 4 is ionized by the electrode 3a and transferred through an oxygen ion conductive plate 2 as a current carrier and returned to an oxygen molecule at the part of the electrode 3b to be discharged to the atmosphere. At the same time, the oxygen molecule of an external space SP3 is sucked in the space SP1 through the diffusion hole 5 of the cap 4 to be diffused throughout said space SP1. The voltage between the electrodes 3a, 3b is set and a limit current value is read by an ammeter A to determine the concn. of oxygen.
|
