Choose from 4-Channels (selectable) for use in ""stacked"" or ""in-line"" systems without crosstalk Synchronised Twin Beams for reli able detection Double Modulated Beam type ensures unsurpassed immunity to direct and reflected sunlight and vehicle headlights Multi-Meter Test Points to accurately monitor alignment voltage Frost Resistant Cover minimises nuisance alarms in harsh weather Automatic Gain Control for maximum stabilityProduct typePhotoelectric Beam SensorDetection systemSimultaneous breaking of 2 beamsInfrared beamLED pulsed beam, Double modulationProtection distanceOutdoor 40m (135ft) or lessIndoor 80m (270ft) or lessMax. beam rangeOutdoor 400m (1350ft) or lessIndoor 400m (1350ft) or lessResponse time50msec. to 700msec. (Variable at pot)Supply voltage12V to 30VDC (Non-polarity)Current consumption75mA or lessAlarm outputDry contact relay output form CContact action Interruption time + delay timeContact capacity 30V AC/DC, 0.5A or lessTamper outputDry contact relay 1b (N/C)Action Activated when cover is detachedContact capacity 30V AC/DC, 0.5A or lessAlarm LEDRed LED (Receiver)ON when an alarm is initiated.Attenuation LEDRed LED (Receiver)ON when beam is attenuated.FunctionsBeam frequency changeover (4ch.)Monitor jack outputAGC circuitFrost proof coverAmbient temperature range-25°C to +60°C (-13°F to +140°F)Mounting positionsIndoor / OutdoorWiringTerminalsWeightTransmitter 380g (13.3oz)Receiver 400g (14oz)AppearancePC resin (wine red)