Optical Barrier VE/VR

Special Features

• Visible red diode emission.
• Insensitivity to ambient light.
• Cast aluminium case with air purged hood for protecting the lens and with water-cooling plate.
• Modular construction allowing rapid maintenance.
• Alignment and checking devices: sensitivity potentiometer, light indicator showing operation.
• Alarm signal, when the lenses become too dirty or when the internal temperature is too high.

The Optical Barrier VE/VR is used in heavy industries with very harsh environment as coke plants, rolling mills etc.

The emitter VE unit emits a high intensity, visible beam of modulated red light. This beam is detected by the photosensitive diode fitted with an optical filter and whose signal is processed by the incorporated circuitry of the receiver VR. The output changes state depending on whether the modulated beam is interrupted or not.
Beam modulation, special optical filter and automatic correction make the sensor insensitive to ambient light.

Presentation

The Optical Barrier VE/VR consists of an emitter VE and a receiver VR:

The VE emitter includes:

• An optical unit equipped with an emitting diode and power supply.
• A terminal block with protection cover or a connector fitted with high temperature cable with protective steel braid.
• A hood for lens protection, with air purging connection.
• An optional water-cooling plate for use at ambient temperature higher than 70 °C (160 °F).

The VR receiver includes:

• An optical unit equipped with a special filter, a photodiode, electronics with high current transistor output, relay or opto solid state relay and power supply.
• A terminal block with protection cover or a connector fitted with high temperature cable with protective steel braid.
• A hood for lens protection with air purging connection.
• An optional water-cooling plate for use at ambient temperature higher than 70 °C (160 °F).

Commissioning

1. Adjustment of light reception:

• Set the Sensitivity potentiometer to max.
• Align the emitter (VE) to get the brightest reflection of the red beam on the receiver (VR) lens.
• Determine on/off points by swivelling the receiver (VR) horizontally and vertically. Fix the receiver in the middle position.
• With optimum alignment, the LED indicator of the receiver (VR) lights up. If it does not light up or if it turns red or orange (Alarm, received light too low): readjust and/or clean VE and VR.