U.S. Code of Federal Regulations
Regulations most recently checked for updates: Nov 03, 2024
(a) Scope and frequency. If you use a chiller to dry a sample upstream of a NO
(b) Measurement principles. A chiller removes H
(c) System requirements. A chiller must allow for measuring at least 95% of the total NO
(d) Procedure. Use the following procedure to verify chiller performance:
(1) Instrument setup. Follow the analyzer and chiller manufacturers' start-up and operating instructions. Adjust the analyzer and chiller as needed to optimize performance.
(2) Equipment setup and data collection. (i) Zero and span the total NO
(ii) Select an NO
(iii) Overflow this calibration gas at the gas sampling system's probe or overflow fitting. Allow for stabilization of the total NO
(iv) Calculate the mean of 30 seconds of recorded total NO
(v) Stop flowing the NO
(vi) Next saturate the sampling system by overflowing a dewpoint generator's output, set at a dewpoint of 50 °C, to the gas sampling system's probe or overflow fitting. Sample the dewpoint generator's output through the sampling system and chiller for at least 10 minutes until the chiller is expected to be removing a constant rate of H
(vii) Immediately switch back to overflowing the NO
(viii) Correct x
(3) Performance evaluation. If x
(e) Exceptions. The following exceptions apply:
(1) You may omit this verification if you can show by engineering analysis that for your NO
(2) You may use a chiller that you determine does not meet this verification, as long as you try to correct the problem and the measurement deficiency does not adversely affect your ability to show that engines comply with all applicable emission standards.