A portable photometer is proposed consisting of a device which is placed over the traffic signal lens. An internal optical system allows measurement of the signal candlepower at various angles of interest. The instrument electronics and light emitting diodes provide a pass/fail indication for each measurement angle, with the go/no-go set point being automatically adjusted to different candlepower values for red, amber and green. Using an extendable arm, the meter may be used by maintenance personnel at ground level.Anticipated results/potential commerical applications of results:A method of checking proper operation and brightness conformity of traffic signals in the field by unskilled personnel, leading to increased safety. Applicable also to many other signalling devices, such as railroad crossing signals.
