SAMPLING:
9. Using the integration time specified in the test plan, obtain samples and record infrared spectra of the desired workplace gases using the entire sampling system. The sampling location may be changed as desired. For tests of duration greater than 2 h, or if the FTIR system is moved during sampling, monitor the system's single-beam response level if changes greater than 5% in non- regions of the single-beam spectrum occur, suspend sampling and record a new background spectrum (see step S). Sample spectra must be acquired at each sampling location for a time period no less than the system response time (see the system test documentation)
10. Repeat step 6 acquire least one posttest sz spectrum of introgen or zero air; confirm the absence of sampling system contaminates.
11. Record at least one posttest CTs spectrum (see step 7); confirm that the system configuration and the system absorption path length (to within 5%) match those of the test plan
12. (optional) Acquire a posttest background spectrum (see step 5)