[Code of Federal Regulations] [Title 40, Volume 30] [Revised as of July 1, 2004] From the U.S. Government Printing Office via GPO Access [CITE: 40CFR1039.510] [Page 502] TITLE 40--PROTECTION OF ENVIRONMENT CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PART 1039_CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION-IGNITION ENGINES--Table of Contents Subpart F_Test Procedures Sec. 1039.510 Which duty cycles do I use for transient testing? (a) Measure emissions by testing the engine on a dynamometer with one of the following transient duty cycles to determine whether it meets the transient emission standards in Sec. 1039.101(a): (1) For variable-speed engines, use the transient duty cycle described in Appendix VI of this part. (2) [Reserved] (b) The transient test sequence consists of an initial run through the transient duty cycle from a cold start, 20 minutes with no engine operation, then a final run through the same transient duty cycle. Start sampling emissions immediately after you start the engine. Calculate the official transient emission result from the following equation: Official transient emission result = 0.05 x cold-start emission rate + 0.95 x hot-start emission rate. (c) Cool the engine down between tests as described in 40 CFR 86.1335-90. (d) For validating cycle statistics, you may delete from your regression analysis speed, torque, and power points for the first 23 seconds and the last 25 seconds of the transient duty cycle.