Sentry Visibility Sensor

The YOUNG 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, & snow).

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Quantity discounts applied during checkout. Excludes sensor cables.

SKU: 73000 Category:

The YOUNG Sentry™ Visibility Sensor measures atmospheric visibility (meteorological optical range) over the range of 30 m to 16 km (0.02 to 10 miles) and can provide various analog and serial outputs including relay contacts for control of external devices.  Designed with anodized aluminum and rugged UV-resistant enclosures, the sensor uses a ‘look down’ geometry, based on proven field experience of the NWS and FAA, to reduce window contamination and buildup from blowing snow.  Continuous duty anti-dew heaters are used to keep optical windows clear.  Thermostatically controlled hood heaters are available on some models for operation in colder environments.  The sensor mounts on a 1½ inch IPS pipe.  An optional Mounting Bracket, Model 74050, is available for mounting the sensor on vertical surfaces (walls, traffic poles, Rohn-tpe towers, etc.).  Hood Extensions, Model 73038, are also available for additional protection in heavily contaminated air found at some sites.

Due to environmental variations (location, installation site, structures, etc.) field calibration of the Sentry™ is recommended and can be performed with a detachable Model 73060 Calibration Fixture.  Calibration of the sensor can typically be done in 30 minutes, or less, and is suggested whenever maintenance/cleaning is performed.

Visibility Range:

30 m – 16 km


± 10% RMSE

Time Constant:

60 sec

Scatter Angle:

42° nominal

Output Options:

0-10 VDC
0-5 VDC
4-20 mA
4-20 mA Isolated
RS-232, RS-422 or RS-485

Relay Options:

2 Control
1 Diagnostic

Power Requirement:

10-36 VDC, 6 VA nominal
18 VA w/ hood heating

Operating Temperature:

-40 to +60°C


0 to 100% RH

Protection Class:

IP66 (NEMA-4X)


88.9 cm (35 in) W x 29.2 cm (11.5 in) H x 30.5 cm (12 in) D


8 kg (18 lb)

Shipping Weight:

9.6 kg (21 lb)