Речь идет о ленточном газоанализаторе.

Контекст:

Tape usage vs. analysis delay time is the performance trade-off made when selecting the tape advance time. The pipeline unit has the capacity for 12 minutes of continuous analysis at 1/4 grain H2S on a single spot of tape. The capacity is unique to our analyzers, since we use an 18 bit A/D conversion of the sensor signal.

A 10 minutes tape advance selected when analysis stops at seven minutes means H2S is not measured 30% of the time, when you approach the alarm point.