(a) Begin a hang-up check within 30 seconds of the completion of the last mode in the test. Use the following procedure:
(1) Introduce a zero-grade gas or room air into the sample probe or valve V2 to check the “hangup zero” response. Simultaneously start a time measurement.
(2) Select the lowest HC range used during the test;
(3) The difference between the span-zero response and the hang-up zero response shall not be greater than 5.0 percent of full scale or 10 ppmC whichever is greater, within:
(i) 50 seconds for gasoline-fueled engine test, or
(ii) 4 minutes for Diesel engine tests, or
(b) Begin the analyzer span checks within 6 minutes after the completion of the last mode in the test. Record for each analyzer the zero and span response for each range used during the preceding test or test segment.
(c) If during the test, the filter element(s) were replaced or cleaned, a vacuum check must be performed per § 86.328 immediately after the span checks. If the vacuum side leak check does not meet the requirements of § 86.328 the test is void.
(d) Read and record the post-test data specified in § 86.337(e).
(e) For a valid test, the analyzer drift between the before-test and after-test (before-segment and after-segment for Diesels) span checks for each analyzer must meet the following requirements:
(1) The span drift (defined as the change in the difference between the zero response and the span response) must not exceed 2.0 percent of full-scale chart deflection for each range used;
(2) The zero response drift must not exceed 2.0 percent of full-scale chart deflection for each range used above 155 ppm (or ppm C), or 3 percent of full-scale chart deflection for each range below 155 ppm (or ppm C).