TunnelTech - Model 602 - Illuminance Photometer Monitor
The TunnelTech 602 Illuminance photometer monitors the average illuminance within a tunnel in accordance with Commission Internationale de l´Eclairage, (C.I.E.), publication 88, 1990 recommendations, the photometer monitors the average illuminance over a range of 0 – 20,000 lux. The detector is a metal/glass encased silicon diode photocell which is filtered to give a response that mimics the performance of the human eye. The detector is perfectly linear within its measuring range and has an instantaneous response to changing light levels.
The primary purpose of monitoring the illuminance in a road tunnel is to ensure the light intensity just inside the road tunnel portal is regulated to the correct level so that drivers do not have to adjust their eyes quickly or become affected by the “black hole” effect where they decelerate rapidly and become a hazard to other road users. This is accomplished in conjuction with The TunnelTech 601 Luminance monitor.
Secondly, once inside the tunnel, as the driver's vision becomes adapted to lower lighting levels, the artificial lighting levels can be reduced in intensity as the distance travelled within the tunnel increases, a relationship known as the “Luminance Reduction Curve”. In other words, lighting within the tunnel is dimmed the further the driver progresses into the tunnel. This means that most of the tunnel is unlighted or has low level lighting to reduce energy costs. The TunnelTech 602 Illuminance photometers monitor the lighting levels along the length of the tunnel and ensure the levels are regulated in line with “Luminance Reduction Curve”.
The TunnelTech 602 Illuminance photometer has a 4-20 mA output to export data to tunnel lighting control systems. The sensor is housed in a rugged glass reinforced polyester enclosure which has an IP65 rating and has an internal thermostatically controlled heater.
Calibration against National Physical Laboratory standards is undertaken at the factory and should not be required in the field.
- Compliant with Commission Internationale de l´Eclairage, (C.I.E.), publication 88, 1990
- Measurement of tunnel illuminance – 0 – 20,000 lux
- Calibrated using standards traceable to UK National Physical Laboratory
- Accuracy +/-3%
- Metal/glass encased Silicon photodiode, Vl filtered to human spectral response
- Rugged Aluminium housing to IP65
- Measurements: Illuminance
- Measuring units: Lux
- Measurement Range: 0 – 20,000
- Ambient Temperature: -20°C to +50°C
- Power supply: 220VAC or 24VDC
- Construction: IP65
- Analogue outputs: 1 x 4-20mA current outputs as standard,
- Photodetector: metal/glass encased silicon diode photocell