2004-06-29_PERMIT FILE - C1981038 (4)

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Section No. 2.2.4 kevisiun No. 0 Late May 1, 1977 Yage 1L of 17 • The sane procedure is used for final flow-rate measure- ments exc0pt that + 20 percent of the average is initially used. Other valid limits may be determined for any sampling site as data are accumulated. a final flow rate deviating from the average by more than 20 percent may result from short-term weather changes. The occurrence of such conditions is noted on the data sheet for that sample. If a final flow rate less than 1.14 m3/min (40 ft3/min) is observed, the sample is voided, because at this low air flow the motor heats up and a valid flow-rate measurement cannot be obtained. J.3 Time Measurements Sampling period start and stop times, for samplers not equipped with a clock switch or an elapsed time meter, are recorded by the operators who start and stop the sampler, respectively. If different operators are involved, they set • their watches to a common reference in order to arrive at an accurate sampling period time. Such a reference could be an office clock that is checked daily or the local telephone company giving time-of-day service. Start and stop times for samplers equipped with a timer switch are taken from the timer's clock start and stop settings. The timer clock is checked, and set if necessary, for the correct time at each filter change. Because timer clocks cannot be set or read to less than +15 minutes an elapsed time meter must be used to determine the number of minutes sampled. Elapsed time meters must be checked as described in Section 2.3 prior to being used. Record the number of minutes of sample collection, deter- mined by the operators watciz or an elapsed time meter, on the hi vol field data sheet. The time of day whicg sample collection started or stopped is also to be recorded on Figure 3.2. •