VD908L Mini Loop - Adjustable Sensitivity
VD908L Mini loops owe their success to a new technology brought to market in an elegant, simple to install package. As usual, it is the software that turns an idea into a solid reliable product.
The module gives an opening pulse when ferrous objects approach the probe position. Modules fit inside a gate or barrier control panel. They wire into all control panel power and safety inputs. A two core probe cable runs from the road to the module.
- Supplied with 15 metre highly resistant cable
- Mini-loops cannot be used for presence
Mini loops, or 'Dynamite' sensors as they are commonly known, respond to magnetic reluctance along one axis. The sensor is designed to be installed vertically in the middle of a road.
Additional information
| Weight | 1.15 kg |
- Supplied with 15 metre cable
- Suitable for solar and battery operated systems
- Power supply: 10-30Vac/dc
- Current draw: 3mA (standby) 25mA (detecting & fault)
- Operating temperature: -35 to 74°C
- Module dimensions: 25 x 39 x 52mm (excluding connections)
- Sensor dimensions: 120 x 18mm diameter
- IP rating: IP65
- Relay: 1A @ 30Vdc isolated
- Sensitivity: 2m²/s
- Impedance: 2-5 Ohms
Applications
Single point sensors have great advantages over conventional loops.
- Saves time and spoil in reduced cable cuts
- Better targeting of the activate sweet spot
- Protects the road surface from break-up an frost damage
- Single point sensors are less affected by drains & services
Road cuts lead to the breakup of the wearing surface. A service trench has been right through the road loop.
Roadside sensor
There are times when setting the the sensor in the centre of the road is difficult or expensive. Resin bonded drives or concrete roads with steel reinforcing may not be disturbed. Sensors can be set at the roadside if it is less than 5m wide, but you should use a module with 10 sensitivities.
The sensor needs to point towards the centre of the vehicle. Set the sensor at 25 to 30 degrees for cars, more for vans.
Installation
Mini loop single point vehicle exit sensors require a small processor module to be installed in the control panel. They are sealed and filled with potting compound to IP68.
Mini loops, or 'Dynamite' sensors, respond to magnetic reluctance along one axis. The sensor is designed to be installed vertically in the middle of a road.
Large steel objects below ground such as tanks or cast iron pipes will affect sensitivity, so it is better to check for them first.
There are two sensor styles, 25mm diameter with 22m of lead in cable, or 17mm diameter with 15m cable.
Installation requires a vertical hole for the sensor around 200mm deep.
The lead can be put in a slot cut into the road surface. Some prefer a plastic conduit that feeds into the bottom of the sensor hole.
