eli Posted May 5, 2007 Share Posted May 5, 2007 Hi all, I incountered a problem recentlly when installing a x band dual tech detector: I am getting false alarms constantlly. The walls of the room is plasterboard, but the only movement around the detector can be FROM BEHIND IT! Can it be that the MW sensor detects from behind? Did anyone encounter this problem, and if so can you suggest a solution for me? Link to comment Share on other sites More sharing options...
nikko Posted May 5, 2007 Share Posted May 5, 2007 A DT needs 2 principles to operate, commonly Passive Infra Red & microwave technology. The DT is used in an envrionment where a standard PIR won't cope, therfore there may be a chance that the PIR side is frequently in fault at your installation. The microwave side can be affected by other influences. It should be noted that a microwaves will pass through glass and brick, therefore the range at which you set the detection needs to be adjusted carefully to the size of the room otherwise something moving outside can trigger it. Lastly, any moving metalic objects in the room, such as fans, cause the microwaves to be bounced all over the place, sending the required doppler effect into chaos. I went up into the attic...I found a Stradavarius & a Picasso. Unfortunately..... Stradavarius couldn't paint, and Picasso made a shocking fiddle. My Facebook page...http://www.facebook.com/home.php#/profile.php?id=1279556853&ref=name Link to comment Share on other sites More sharing options...
Cubit Posted May 5, 2007 Share Posted May 5, 2007 i was under the impression that dual techs or dt's (as they are also known) needed both microwave and heat detection to activate the sensor alarm signal, sounds like it hasnt been set up properly He wasn't shouting, he was emphasising the specific issue. A fact you seem to have missed completely. Link to comment Share on other sites More sharing options...
eli Posted May 5, 2007 Author Share Posted May 5, 2007 A DT needs 2 principles to operate, commonly Passive Infra Red & microwave technology. The DT is used in an envrionment where a standard PIR won't cope, therfore there may be a chance that the PIR side is frequently in fault at your installation. The microwave side can be affected by other influences. It should be noted that a microwaves will pass through glass and brick, therefore the range at which you set the detection needs to be adjusted carefully to the size of the room otherwise something moving outside can trigger it. Lastly, any moving metalic objects in the room, such as fans, cause the microwaves to be bounced all over the place, sending the required doppler effect into chaos. nikko, you are right, the PIR is frequantly at fault in this installation, this is why I used D/T, but I didn't think the detector will also penetrate the wall from behind. do you have expiriance with this kind of problem? If so what can be done? Link to comment Share on other sites More sharing options...
Guest anguscanplay Posted May 5, 2007 Share Posted May 5, 2007 nikko,you are right, the PIR is frequantly at fault in this installation, this is why I used D/T, but I didn't think the detector will also penetrate the wall from behind. do you have expiriance with this kind of problem? If so what can be done? hi eli is this for yourself or are you installing profesionally what make of d/t are you using - it cant detect "from behind" as the coverage pattern is usually a ballon shape microwave`s will pick up a totally different set of triggers than a pir - water pipes are a little known problem is the mounting surface rock solid - could a door slamming be shaking the sensor are you sure the microwve is on ie did you replace the lid whilst the sensor was powered up - it will could see this as a blockage and switch to pir only are the links corrctly sited internally - you may have switched the microwave off does the sensor need a switched input when set to enable the microwave - so called green technology next step is to post which color lights are showing at different states - unset,set, triggered and stable along with the manf name and model no Link to comment Share on other sites More sharing options...
FASTCAR Posted May 5, 2007 Share Posted May 5, 2007 Hi , Some have a dip setting for either or both technologies to trigger the alarm relay , choose the wrong one and this would give you false alarms. Regards Link to comment Share on other sites More sharing options...
breff Posted May 5, 2007 Share Posted May 5, 2007 The microwave part of a DT can detect up to 1 metre behind it, this is why they should not be mounted 'back to back' as they can interfere with each other. Look in the instructions for any DT. The opinions I express are mine and are usually correct! (Except when I'm wrong)(which I'm not) Link to comment Share on other sites More sharing options...
Guest anguscanplay Posted May 5, 2007 Share Posted May 5, 2007 The microwave part of a DT can detect up to 1 metre behind it, this is why they should not be mounted 'back to back' as they can interfere with each other. Look in the instructions for any DT. we never had a problem with them " seeing behind themselves" rockonet i wise - shows ballon shape with dead spot each side and behind always seeing them screwed together at right angles in the local supermaket? two in the same room looking directly at each over - not so sure Link to comment Share on other sites More sharing options...
whistle Posted May 5, 2007 Share Posted May 5, 2007 We have fitte loads of Rockonet IWise DT's and had no problems at all. Even with the mask on grade 3 jobs. Link to comment Share on other sites More sharing options...
misterg Posted May 5, 2007 Share Posted May 5, 2007 Hi all,I incountered a problem recentlly when installing a x band dual tech detector: I am getting false alarms constantlly. The walls of the room is plasterboard, but the only movement around the detector can be FROM BEHIND IT! Can it be that the MW sensor detects from behind? Did anyone encounter this problem, and if so can you suggest a solution for me? don't wish to teach granny how to suck eggs BUT i presume there is no vibration/movement on the plasterboard wall ... it must be fixed to a stable surface to prevent false alarms for obvious reasons Mister G Link to comment Share on other sites More sharing options...
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