For H<sub>2</sub>S detection,sensitized tapes indicate H<sub>2</sub>S presence by means of discoloration of an exposed spot on the tape. The shade of the color on the spot depends upon the concentration of H<sub>2</sub>S and().
A、air temperature at the time of the exposure
B、air pressure at the time of the exposure
C、humidity at the time of exposure
D、duration of the exposure