400-73000 Sentry Visibility Sensor

The 400-73000 Sentry™ Visibility Sensor measures atmospheric visibility (meteorological optical range) by determining the amount of light scattered by particles in the air (smoke, dust, haze, fog, rain, and snow).

Performance in all weather conditions is achieved with an integrated design that keeps all cabling internal to the sensor for complete protection from hazards. The sensor is made from anodized aluminum and rugged, UV-resistant fiberglass enclosures. Based on the proven field experience of the NWS and FAA, the sensor uses a "look down" geometry to reduce window contamination and clogging from blowing snow. The optical windows have continuous duty anti-dew heaters. Optional thermostatically controlled external hood heaters are available for additional protection in extreme environments. All power and signal lines to the Sentry™ are protected with surge and EMI filtering to ensure uninterrupted service for the life of the sensor.

Installation and maintenance are simple with the Sentry™. A sturdy mounting flange located on the bottom of the main enclosure mates with a user-supplied 1-1/2 inch IPS mounting pipe. Power and signal cables are installed through waterproof cable glands on the bottom of the main enclosure to terminal boards for simple but reliable connections.

Calibration of the Sentry™ in the field is as simple as attaching a factory supplied calibration fixture and following a procedure that takes less than 30 minutes.