TITLE 40 - PROTECTION OF ENVIRONMENT

CHAPTER I - ENVIRONMENTAL PROTECTION AGENCY

SUBCHAPTER C - AIR PROGRAMS

PART 90 - CONTROL OF EMISSIONS FROM NONROAD SPARK - IGNITION ENGINES AT OR BELOW 19 KILOWATTS

subpart d - EMISSION TEST EQUIPMENT PROVISIONS

90.309 - Engine intake air temperature measurement.

  (a) The measurement location must be within 10 cm of the engine intake system (i.e., the air cleaner, for most engines.) (b) The temperature measurements must be accurate to within 2 C.