To quickly and correctly judge a life expectancy of a chemical filter in a simple and easy fashion.
A prescribed amount of the same adsorbent as that composing a judgment object chemical filter is placed in a prescribed flow passage, and a prescribed gas of the prescribed concentration is fed thereto at a prescribed flow rate. A relational expression at that time based on correlation data of the prescribed gas concentration of a secondary side to already-adsorbed amount of chemical substances to an adsorbent is obtained. Then, the adsorbent is sampled and the prescribed gas concentration of the secondary side is measured in the same conditions as those for obtaining the correlative data to obtain sampling data; the already-adsorbed amount of the chemical substances to the prescribed amount of the sampling adsorbent is judged from the relational expression and sampling data; residual adsorbing amount until a breakthrough at a prescribed amount of the adsorbent composing the chemical filter being the judgment object, is calculated from the already-adsorbed amount of the sampling adsorbent and the relational expression; a unit adsorbed amount per unit time is calculated from integrated air passing time and the already-adsorbed amount of the sampling adsorbent; and the time until the breakthrough is calculated from the unit adsorbed amount and residual absorbing amount.
NISHIO HISAO
MORIYA KUNIHIKO
NAKAMURA YOSHIRO
YAMATO SCIENT CO LTD
Nobuhiko Nakamura