T/VIS-TR – VISIBILTY MONITORING SYSTEM

Visibility measuring system according to the transmission principle, specially developed for the requirements in tunnels. The measuring range for the analog signal is freely assignable.

Categories: Environmental Instruments, Product Range, Tunnel Monitoring

Description
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Description

In-situ visibility monitoring by optical transmission

Visibility monitoring is used to control the tunnel ventilation at normal operation. If and with how much power artificial ventilation by jet fans is operated depends on the measured visibility.

Visibility is stated in the form of an extinction coefficient that corresponds to the light attenuation caused by air pollution.

The monitoring system consists of a light emitting and receiving sensor and an optical reflector. The sensor determines the light transmission along a 10 m measuring path. Visibility and extinction coefficient are calculated based on the determined transmission.

Features:

Visibility measurement by optical transmission method
Reliable measurement along a path of 10 m parallel to the tunnel axis
Parametrisation of the sensor via Modbus RTU
External cable length of 1000 m to tunnel control system
Signal output either via analogue and relay outputs or RS-485 with MODBUS RTU protocol
Visible LEDs show sensor status

System:

Sensor mounted on tunnel wall parallel to tunnel axis aligned with reflector
Reflector to reflect the light emitted by the sensor mounted on the tunnel wall in a distance of 10 m from the sensor
Terminal box to connect the sensor, power and to connect to the tunnel control system

Advantages:

Specifically developed for application in tunnels
No separate control unit required
Influence of contamination of optics on the measuring results is compensated
Easy configuration
Corrosion resistant against aggressive tunnel atmosphere
Sensor and reflector can be replaced quickly, no tools, no re-alignment required
No expendable parts
Extremely low maintenance requirements
Optional combination with CO sensor

Technical Specifications:

VISIBILITY MEASUREMENT
Measuring method	Optical transmission of visible light passing the measuring path twice
Measured values	Dust concentration in mg/m³ Opacity in % Extinction Visibility (Extinction coefficient VIS k)
Measuring range	0 to 0,015 E/m (configurable up to 0,15 E/m) 0 to 97,5 % opacity
Response time	> 2s to 180 s, configurable
Light source	LED green, 530 nm
Measuring path	Distance Sensor – Reflector 9,5 to 11 m Measuring path length 19 to 22 m
Orientation	Parallel to tunnel axis

OUTPUTS
Analogue outputs	1 x 4-20 mA, 400 Ω, isolated can be assigned any measured value and output range
Output range	configurable, typical: 0 to 0,015 E/m
Contacts	2 x Status (NO) Max. 48 V / 0,5 A
Digital interface	1 x RS-485 MODBUS RTU

SENSOR
Model	D-R 220T M
Operating voltage	24 VDC ± 10 %
Current consumption	Ca. 0,4 A
Service interface	USB 1.1
Temperature range	-20 to 50 °C
Protection class	IP 65
Dimensions	150 x 220 x 140 mm
Weight	Ca. 2,7 kg
Material	Polyamide, approx. RAL5017, Flammability rating: B1 (UL 94 V0)

REFLECTOR
Model	D-R 220T R3
Protection class	IP 65
Dimensions	150 x 110 x 140 mm
Weight	Ca. 1,6 kg
Material	Polyamide, approx. RAL5017, Flammability rating: B1 (UL 94 V0)

DUST PROTECTION TUBE
Model	D-R 220T T
Dimensions	280 x 110 x 100 mm
Weight	Ca. 3 kg
Material	Stainless steel 1.4571 / 316Ti

TERMINAL BOX
Model	D-TB 100T
Operating voltage	90 bis 264 VAC, 48 bis 62 Hz
Power consumption	ca. 30 VA
Protection class	IP 66
Dimensions	160 x 160 x 110 mm
Material	approx. 1,5 kg
Model	Polycarbonate, RAL 7035, Flammability rating: B1 (UL 94 V0)

CONFORMITIES
Electrical standards	2006/95/EC Low voltage directive (LVD) 2004/108/EC Electromagnetic compatibility (EMC) EN 61326-1
Tunnel safety standards	AT: RVS 09.02.22 DE: RABT 2006 CH: ASTRA RL 13001, Fachhandbuch BSA