The tunnel entrance photometer is supplied by WRTL to provide the portal luminance measurements required by the i-TunneL® B-Scout monitoring and control system.
Along with the various options such as wash-wipe systems and the mounting brackets, the photometer is usually situated close to the stopping distance (SD) of the particular road in front of the tunnel entrance portal.
The device can be powered directly from the B-ScoutMaster which has suitably fused mains power outputs. Also connected to the B-ScoutMaster is the 4-20mA signal generated in proportion to the luminance of the area within the viewing angle.
Key Features
The tunnel entrance photometer is supplied by WRTL for use in conjunction with the i-TunneL® lighting control and monitoring system. Available in a variety of measuring ranges, the photometer provides a stable 4-20mA current loop output directly proportional to the portal luminance. This signal connects directly to the B-ScoutMaster controller providing important light level data enabling control of the tunnel lighting. Various optional extras are available such as mounting brackets and wash-wipe systems providing a solution for the most demanding specifications.
Features & Benefits
- Available in a variety of measuring ranges and viewing angles
- Provides accurate measurement of tunnel portal luminance
- Connects directly to the B-ScoutMaster controller
- Supplied in a stainless steel powder coated IP65 enclosure with sun canopy
- Condensation control by internal 6W heater
- Wash-wipe facility available
- Brackets available for wall and column mounting with pan and tilt adjustment
- Accuracy better than +/-3%
- *Aligned & commissioned by WRTL engineers
* - The installation of the bracket, photometer and wash-wipe systems including the connections up to the B-ScoutMaster are the responsibility of others
Connection Details
The diagram below shows a typical installation with wash-wipe control and water level indicator. It is important to consider the precise requirements of each installation carefully.
These connections are normally made in a suitably sealed enclosure (available from WRTL) mounted at the base of the photometer column or within a local distribution cabinet
Mounting Bracket
Available to order separately is the photometer mounting bracket. Manufactured from cast aluminium the bracket provides a rigid support for the photometer. The stainless steel swivel mount provides pan and tilt adjustment which is then locked in the final position.
A special conversion kit is also available for mounting to columns of 76mm diameter.
Washer Unit
Available to order separately, the wash-wipe system with five litre capacity allows for periodic cleaning of the photometer front screen. The B-ScoutMaster provides power and switch connections* for the wash-wipe, enabling the necessary control based on a user configurable frequency. A float level sensor is also included which enables the detection and alarm of low water conditions. The washer bottle must be mounted no further than 5m from the photometer.
Calibration & Maintenance
The photometer is supplied calibrated to the desired range. The light sensitive component is a very stable silicon photodiode, meaning a calibration interval of five years should be quite sufficient. The wiper blade should be inspected for damage approximately every two years and replaced when necessary. The water bottle should be filled on a regular basis depending on the frequency of washing.
Options
- Alternative viewing angles available (when conditions do not allow the photometer to be sited at the SD)
- Specific luminance ranges
- Varying supply cable lengths (to account for column height)
- Column-mount bracket kits
- Remote connection enclosure available
Technical Data
Photometer
Supply | 220 – 240VAC |
Detector | Silicon photodiode |
Measuring Angle | 20o as standard |
Measuring Range | As specified at ordering stage – e.g. 0 - 6,500cd/m2 |
Accuracy | Better than +/- 3% |
Output Signal | 4 – 20mA |
Temp. Range | -30oC - +50oC |
Internal Heater | 6W (PTC Heating) |
Material | Housing, mounts and holder for washer – stainless steel |
Sealing (Housing) | IP65 |
Weight | 6.6kg (with built in wiper) |
Mounting Bracket
Material | Main body - Cast aluminium Swivel mount – Stainless steel |
Finish | Powder coat finish to BS10A03 |
Weight | 3kg (Supports 20kg max.) |
Projection | Allows movement for both pan and tilt |
Mounting | Wall as standard (column mount kits available) |
Washer Unit
Supply | 230VAC |
Material | Stainless steel |
Finish | Powder coat finish to BS10A03 |
Capacity | 5 litres |
Pumping Height | 5m maximum |
Sealing | IP65 |
Priming | Self priming |
Dimensions & Range
Type No. | Description |
IT-TLS 420SW | Tunnel photometer with wash wipe |
IT-TLS WW1/5 WASH | Photometer washer unit |
IT-TLS SW/S MOUNT | Adjustable photometer wall bracket with swivel mount |
IT-TLS COL KIT | Photometer column mount kit (required in addition to wall bracket) |
IT-TLS REM CONNECTION | Tunnel photometer & wash-wipe remote connection enclosure |
Associated Products
IT-B-SCOUTMASTER B-ScoutMaster RS-485 Control & monitoring unit in wall mount housing
Data sheet
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