§ 1065.342 Sample dryer verification.

(a) Scope and frequency. If you use a sample dryer as allowed in § 1065.145(e)(2) to remove water from the sample gas, verify the performance upon installation, after major maintenance, for thermal chiller. For osmotic membrane dryers, verify the performance upon installation, after major maintenance, and within 35 days of testing.

(b) Measurement principles. Water can inhibit an analyzer's ability to properly measure the exhaust component of interest and thus is sometimes removed before the sample gas reaches the analyzer. For example water can negatively interfere with a CLD's NO_X response through collisional quenching and can positively interfere with an NDIR analyzer by causing a response similar to CO.

(c) System requirements. The sample dryer must meet the specifications as determined in § 1065.145(e)(2) for dewpoint, T_dew, and absolute pressure, p_total, downstream of the osmotic-membrane dryer or thermal chiller.