THE necessity of being able to evaluate the degree of smoke in the diesel engine exhaust is becoming universally recognized. Various methods of measuring smoke are discussed briefly.
Of these methods, the light-absorption, photo-electric cell, sampling-type smokemeter appears to be the most satisfactory. The fundamental requirement for this type of smokemeter is that it gives a true indication of smoke values.
Other design requirements are listed, and a smokemeter described which appears to meet them with reasonable satisfaction. The principal departures in the design of this smokemeter from that of others of the same type are in the greater length of the measuring tube, the use of a flashlight-type bulb with reflector for a light source, and the use of a vacuum pump to draw the sample through the smokemeter.
A scale for measuring smoke, “smoke density per unit length of smoke column,” is proposed, which should allow all laboratories to interpret smoke readings the same.
