Active And Passive Light Probe

Light sensor and source are in a small, rectangular block at the end of a long flexible cable. Circuitry, controls, speaker and batteries are in a small box at the other end of the cable. When the light is detected, the unit produces a tone whose pitch is proportional to the amount of light falling on the sensor; the higher the tone, the more light is being detected. Unit can also operate as an active light probe. It has its own light source and can, therefore, measure the amount of light from this source that is reflected by the object being examined. Light sensor has an adjustable focus, for distances from 0 to 1 centimeters or 0 to 0.4 inches from the end of the probe. Controls include on an off switch, active and passive sensing switch and focus adjustment. Power: rechargeable battery. Box measures one inch by two inches by three inches; separate model is enclosed in a pen light shaped case with controls on the back.