Subscriber Discussion

Dual Beam Infrared Detectors

Need a recommendation on an "dual beam infrared motion detector OR alarm sensor" for a "warehouse" overhead door that is never used. Also, it is right next to a train track.

Any guidance would be greatly appreciated. Will be attached to strobe light and possibly the alarm system. On a fact gathering mission only at the moment. Thanks.

Does it have to be a motion sensor? Can it be a door contact?

Will the railroad track next to building cause a problem at all?

Not sure what you mean by 'dual beam' - either dual IR emitters within a single transmitter for fewer false positives, or two separate emitters, on separate lines-of-sight. But, I find OpTex has just about everything you might need, and has much better than average tech support - US based. I use a lot of thier battery-powered, wireless models. Inovonics makes complementary receivers, with dry-contact outputs for your strobes and such.

Thanks for your comments Michael! I'm glad that you like our iSeries wireless products and find our tech support "much better than average"! We try hard!

Thank you! I'll look into it. And Brian, yes it can be a door contact. I'm just trying to have ideas geared for this warehouse prior to actually visiting it.

So, this is a matter of choosing the lesser of two evils: Motion sensors are notorious false alarm sources. However, overhead door contacts are too!

Is the purpose of this alarm point to see if someone is opening the overhead door?

In this application, I think a door contact would be better because the door is uncommonly used and rolling a forklift over a contact seems unlikely. However, I have seen simple wind buffeting on a closed overhead door cause it to move around enough to trip the contact.

I was worried about that particularly because the train track runs a few feet behind the overhead door. The door is not really used either but there is concern about entry through those doors.

I doubt the train is ripping through there fast enough to cause buffeting or vibration issues, but with that said:

1. A contact is only useful if the door is opened.

2. If the risk is someone cutting a hole in the door and climbing through, then your Dual tech motion sensor might be the best answer.

Interesting wording "Dual Beam Infrared Motion Detector". Normally "Dual Beam" would apply to photoelectric (Active Infrared) beams, while "Dual Motion Detector" would apply to a motion detector utilizing PIR (Passive Infrared) and microwave, or some 2nd technology. As Brian mentioned, the use of a door contact will only detect the door being opened...not cut through. Using a dual motion detector will limit false alarms, but placement and other factors are critical for trouble-free operation. (i.e. shelving near the detector where a rodent might appear large to the detector, air drafts from the door jambs, etc.). A dual or quad photobeam across the doorway would greatly reduce any false alarm potential and also protect against somebody cutting through the door. However, I would recommend double-stacking the beams to avoid missed alarms by somebody easily going under (or over) a single set of detectors. Hope this helps.

Thanks all, because of the location of the door it is a bit tricky. Thanks for all the suggestions, greatly appreciated.

I suggest the Optex Redscan Laser device. If budget is not a problem.

Takex has a very extensive range. I've used them in the past and they're very good. They have dual and quad beam models up to 660ft