Background Luminance

The Model 5000 Background Luminance Sensor measures the background sky intensity, which is used with transmissometers or visibility sensors to calculate the Runway Visual Range.

The optoelectronics assembly is mounted inside a weatherproof enclosure with a glass front window and an integral hood.

A high-stability silicon photodiode with a linear response spanning over 7 orders of magnitude measures the background sky intensity.

The photodiode's characteristic is compensated by a photopic correction filter centered at 555 nm, ensuring that the reading conforms to within 3% of the CIE Photopic response.

The optoelectronics assembly is temperature-controlled and features a logarithmic characteristic to ensure accurate readings across the full range of the sensor when used with a standard analog-to-digital converter.