Green light penetrates through the smoke

摘要

The OMl diesel engine smoke emission meter from Telonic Instruments is a hand-held instrument that detects the opacity of diesel smoke by a green light emitting diode pulsed through the smoke plume at 625 times a second. Used in conjunction with Celesco emitter/detector heads from the 107 or 300 range, it can make end-of-line or in-line measurements. The photodetector has an integral amplifier and is connected to the meter via a screened multicore cable. Opacity and smoke density are displayed on an LCD in real time with peak values that can be reset by the user. Digital signal processing ensures accuracy and low drift. The control functions are microprocessor based and include auto calibration and self test.