This SAE Standard applies to off-road, self-propelled work machines used in construction, general-purpose industrial, agricultural, forestry, and specialized mining machinery as defined in SAE J1116, and establishes the following minimum performance levels in the operators environment for the seated position. Minimum operator enclosure pressurization and ventilation levels in the operators environment for the seat position. Maximum humidity and minimum temperature differential under air conditioning operation. Minimum temperature differential under heater operation.