Hi I'm a complete novice looking for advice. I'm changing my conservatory into an office. I want to put a PIR into the room & thought about using a dual tech (infra red & microwave) PIR. My Alarm guy who I've known for years is reluctant to advise me as he isn't very keen on PIR's in conservatories.The gradings from 1 to 3 confuses me a little bit. Also the range as I guess ideally I'd want something to only go as far as the windows & not through. What I've read so far on dual tech PIR's is that they are infra red & microwave, so with 2 different types of triggers & needing both to alarm, making them more reliable. Plus they seem to be zone 2 & 3 so more harsh environment, so less prone to temp changes & other things like insect damage. The thing that worries me is the large range, typically 10mtrs min & if I should go for a grade 3 over a 2.

Wonder if anyone could advise me?

Thanks

Hi,

The 'grading' refers to the standard that the device conforms to in EN50131 standards etc-not how large a range it has or whatever.

A dualtec can go in a conservatory-the passive bit will not penetrate glass normally the microwave may, but the sensitivity of the mw can be adjusted once fitted-your alarm guy should know these things already!.

A dt will be absolutely fine in a conservatory, just make sure the microwave is setup properly.

Id advise a higher freq microwave. This will penetrate the glass less etc. ie a k-band rather than x band microwave. Id only fit a dt in a conservatory, never a pir only.

or fit optex fx50sq, they're made for cons..

or fit optex fx50sq, they're made for cons..

thought they were made by cons.

Thanks for all the advise guys.

So a DT such as a Honeywell DT 7550A would be a good choice. Or a optex fx50sq which appears to be just a IR quad unit?

I also have a plastic roof, so I guess anything with a glass shock sensor would be a bad idea?

Thanks

Vibration detectors are fine if specced / fitted corectly. probably not best on a roof due to nuisance tripping.

dt 7550a or 7435 are k band so will be better suited to a thin wall environment.

love opted pirs but personally I wouldn't use in a conservatory . imo pits have a problem when the area the detector is in gets hot. ie approaching body temp. Temp compensating detectors usually look for 1.6 - 2 degrees difference to background. as the temp rises this differnces gets smaller to allow detection. some pirs get so sensitive at this time they alarm. Not saying the fx will as i dont use them. used to rate the cx series when they were made mind

Edited July 16, 201015 yr by jameswilson

Vibration detectors are fine if specced / fitted corectly. probably not best on a roof due to nuisance tripping.

dt 7550a or 7435 are k band so will be better suited to a thin wall environment.

love opted pirs but personally I wouldn't use in a conservatory . imo pits have a problem when the area the detector is in gets hot. ie approaching body temp. Temp compensating detectors usually look for 1.6 - 2 degrees ydifferent to background. as the tem rises this diffrnces gets smaller to allow detection. some pies get so sensitive at this time they alarm. Not saying the tx w

he actually talks like this in real life .............

lol, just wondering.