67 Pa. Code § 169.3
The following words and terms, when used in this chapter, have the following meanings, unless the context clearly indicates otherwise:
Diesel smoke-Particles, including aerosols, suspended in the engine's gaseous exhaust stream of the engine which obscure, reflect or refract light.
Full load power-The power produced, at the speed being considered, when the throttle lever is placed in the maximum fuel position.
Idle speed-The low idle speed of the engine as specified by the manufacturer.
Intermediate speed-The peak torque speed or 60% of rated speed, whichever is higher.
Opacity-That fraction of light transmitted from a source which is prevented from reaching the observer or instrument receiver expressed in percent [opacity = 100%(1-transmittance)].
Peak torque speed-The speed at which the engine develops maximum torque as stated by the manufacturer.
Rated brake power-The maximum brake power output of an engine in horsepower (watts) as stated by the manufacturer, in accordance with SAE J270.
Rated speed-The speed at which the manufacturer specifies the rated brake power of an engine.
Resolution-The minimum distinguishable reading, for a given trace width and scale combination, expressed as a percent of full-scale.
Smoke opacimeter-An optical instrument designed to measure the opacity of diesel exhaust gases. The full flow of exhaust gases passes through the optical unit. A smoke opacimeter is described in SAE J255.
Span-The distance between zero and full-scale deflection of the readout device used with the smoke opacimeter.
Vehicular diesel engine-A compression ignition internal combustion engine of less than 1000 horsepower, 745,700 watts, used to propel on land, nonrail, mobile equipment.
67 Pa. Code § 169.3