Author Topic: New Gent detectors can't be tested by airosols spray ?  (Read 4168 times)

Offline Benzerari

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New Gent detectors can't be tested by airosols spray ?
« on: November 19, 2008, 10:02:28 PM »
Have heard that new s-quad detectors of Gent can't be tested by a usual solo aerosol spray, is that correct and why?

Offline Allen Higginson

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Re: New Gent detectors can't be tested by airosols spray ?
« Reply #1 on: November 20, 2008, 12:47:59 AM »
Have heard that new s-quad detectors of Gent can't be tested by a usual solo aerosol spray, is that correct and why?
Haen't heard this as yet but I'd go for (a) the standard test gas that all us engineer types use has been found to contaminate the S-Quad's mystical internal workings or (b) because of "findings" indicated in (a) Honeywell have their own specific test gas approved for testing of said detectors to keep within warranty issues.
There is also a possibilty that there is a genuine technical reason that the test gas won't activate the detector because the smoke has no temperature qualities (ie - aeresol propelant is cold whereas fire smoke has heat in it).
I know in the minerva 16/80 series you turned off the rate of rise sensing during the walk test so that the smokies went off quicker.

Offline David Rooney

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Re: New Gent detectors can't be tested by airosols spray ?
« Reply #2 on: November 20, 2008, 10:42:56 AM »
The old black tins of no climb tester definately screws up even the latest non addressable heads.

We only ever use the white tins now but haven't heard about this revelation......
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Offline Benzerari

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Re: New Gent detectors can't be tested by airosols spray ?
« Reply #3 on: November 20, 2008, 12:09:33 PM »
Have heard that there are two sort of s-quad, the cheaper ones and the expensive ones, it's the expensive ones that I heard are very cleaver to distinguish between i.e. the steam particles from a genuine smoke particles and also they have dual chambers and the alarm threshold is achieved only if both chambers detects smoke... etc therefore the normal solo spray wouldn't trigger them live you have to set the system in test mode to trigger them quicker, the test mode in fact neglect some of the features... etc for quick test proposes... etc

But, I would prefer to hear more accurate info, from a well informed Gent engineer if possible.


Offline Big_Fella

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Re: New Gent detectors can't be tested by airosols spray ?
« Reply #4 on: November 20, 2008, 03:28:19 PM »
Indeed the more 'advanced' detector will not trigger with the aerosol spray.  Nor will the 'simpler' types of Gent detector when they are set on specific 'states'.  this is to overcome false alarm issues and that the detector is looking for a particular change in state rather than a reflection of scattered light in the element.

The panel does have to be put into test mode to test these devices correctly, and can be done with a standard aerosol spray eg. no climb spray etc.

When putting in test mode the panel will not look for a combination of sensing element changings but will treat the elements individually.

For example.  the Dual Optical Detector.  Standard spray won't generally trigger this device, but if in test mode the backward and forward scatter optical sensing elements will be treated separately and thus testing of the device can be carried out.
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Offline Benzerari

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Re: New Gent detectors can't be tested by airosols spray ?
« Reply #5 on: November 20, 2008, 03:54:30 PM »
Indeed the more 'advanced' detector will not trigger with the aerosol spray.  Nor will the 'simpler' types of Gent detector when they are set on specific 'states'.  this is to overcome false alarm issues and that the detector is looking for a particular change in state rather than a reflection of scattered light in the element.

The panel does have to be put into test mode to test these devices correctly, and can be done with a standard aerosol spray eg. no climb spray etc.

When putting in test mode the panel will not look for a combination of sensing element changings but will treat the elements individually.

For example.  the Dual Optical Detector.  Standard spray won't generally trigger this device, but if in test mode the backward and forward scatter optical sensing elements will be treated separately and thus testing of the device can be carried out.

Thanks Big Fella for these confirmations  :)