GLS-LCCT
The GLS-LCCT is an outdoor rated (IP67) sensor capable of reading daylight intensity (Lux) and Color Temperature (K) as well as RGB and HSV in CIE 1931 2° Standard Observer color coordinates. The sensor is designed to be installed on the roof of a building in direct sunlight and features an internal heater to handle winter weather conditions. The sensor delivers Lux values between 0 and 100,000 in 10 Lux increments. Color temp is provided between 2000K and 25,000K (optimized for 2700 to 5700K). The field of view is 360° semispherical, meaning the sensor collects light from 90° in any direction relative to straight up. Color calculations are based on the D65 white illuminant using sRGB color gamut.
Applications
- Color Temperature and Intensity sensor for driving interior dynamic white fixtures
- RGB sensor for translating observed color to RGB fixtures
- Exterior illuminance sensor for activation of exterior lighting (see GLS-LEXT Replacement Considerations)
Typical CCT Reading with Occasional Clouds
GLS-LEXT Replacement Considerations
Crestron discontinued the GLS-LEXT with the introduction of the GLS-LCCT. The GLS-LEXT is a calibrated purpose built sensor for detecting light levels above or below a threshold. The sensor is generally positioned on the side of a building facing North out of direct sunlight, effectively placing it in the shade. The deployment for the GLS-LCCT is completely different with the sensor recommended to be installed on the roof of the building in direct sunlight (shadows produce cooler color temperatures). This type of installation may not be ideal for use as an exterior photocell. In an effort to determine the best settings for the GLS-LCCT Chief Integrations deployed a GLS-LCCT and GLS-LEXT mounted in the same enclosure with the LEXT facing North as specified and the LCCT facing upward. Data was captured over for a month and analyzed. When using GLS-LEXT a system typically switches between nighttime and daytime around 1.25V DC (the logic threshold on Crestron Versiports and Digital Inputs). 0-10V values are scaled from 0 to 65535. 1.25V translates to ~8200. Below is a graph of data from one of the recorded days showing the GLS-LEXT using 0 to 65535 units and the GLS-LCCT showing true Lux readings.