Visibility Sensor
GMU – (General Marine Use) Sensor Offers Great Control
The GMU visibility sensor measures atmospheric visibility (meteorological optical range) by determining the amount of light scattered by particles (smoke, dust, haze, fog, rain, & snow) in the air that passes through the sample volume.
A 42-degree forward scatter angle is used to ensure performance over a wide range of particle sizes. MOR is calculated by the user by converting the received signal strength (extinction coefficient, σ) using Koschmeider’s formula, MOR (Km) = 3/σ.
The windows use continuous duty anti-dew heaters and thermostatically controlled external hood heaters are optional for protection in extreme environments. All power and signal lines to the Visibility Sensor are protected with surge and EMI filtering to help guarantee uninterrupted service for the life of the sensor.
Calibration of the fog detector in the field is as simple as attaching a factory supplied calibration fixture and following a procedure that takes less than 30 minutes. Semiannual calibration is recommended.