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FIRE SERVICE AND GENERAL FIRE SAFETY TOPICS => Technical Advice => Topic started by: AnthonyB on January 27, 2009, 06:16:08 PM

Title: Effect of test gas/smoke on detector heads
Post by: AnthonyB on January 27, 2009, 06:16:08 PM

Got this as a PM:

"is it just an urban myth that using solo gas to test gent detectors causes false alarms due to the gas causing corrosion in the detector?"

Would fire alarm engineers like to comment?

Title: Re: Effect of test gas/smoke on detector heads
Post by: Graeme on January 27, 2009, 06:37:58 PM

never heard that one before although  i have seen some clueless nupties spaying the can which is designed to be used with the dispersing cup,straight into the detector with the can practically touching the detector. 

Title: Re: Effect of test gas/smoke on detector heads
Post by: Davro on January 27, 2009, 08:12:30 PM

I've heard that through this forum but cant seem to find the page, but i only thought it was not to be used on the new range of detectors. I went on a commissioning course for the sms sentri systems and they did not say anything about that solo cans are not to be used.

Title: Re: Effect of test gas/smoke on detector heads
Post by: JonnyG on January 27, 2009, 09:51:09 PM

I've been using the test can with the solo head on the new Gent heads for about a year now. Haven't had any bother at all.

I like the new Gent heads, seem to be a lot more robust.

Title: Re: Effect of test gas/smoke on detector heads
Post by: Ark Angel on January 27, 2009, 10:06:37 PM

I'm with JonnyG

Used sparingly I cannot see any issue with using solo test gas on the S-Quad heads. You may of course end up with someone who tries to set off a dual optical with test gas in which case they will have great difficulty in setting the head off and will use a lot of gas to do it leaving residue, but if they are tested as per the manufacturers reccommendations then this shouldn't be an issue.

Title: Re: Effect of test gas/smoke on detector heads
Post by: Wiz on January 29, 2009, 05:48:01 PM

The Solo detector tester (white can / blue cap) has been specifically developed to avoid leaving corrosive contaminents on or in detectors. It was developed as a better alternative to the Canned Smoke (black tin / black cap) which is known for leaving a sticky residue in and on the detector. Only the white can version should be used in Solo dispenser unit.

Title: Re: Effect of test gas/smoke on detector heads
Post by: Thebeardedyorkshireman on February 03, 2009, 11:14:22 AM

Hello boys and girls, its been a long time since I posted due to a techie problem with the site, but i have been marking your homework.....
 Test Gas
I have discussed this in the past at Director level with most of the detector manufacturers and the original problem of the residue was solved by the later test gas.  My understanding of the present situation is a potential problem with the properties of the propelant gas in the can. In large quantities this can have a detrimental effect on the waterproof membrane ( varnish) painted on the detector pcb during manufacture to enhance the environmental protection of the board and components.

wow what a gob full that was. In short: dont keep spraying the tester in the head if it wont go off or eventually you won't be able to stop it going off on it's own!!
Dave

Title: Re: Effect of test gas/smoke on detector heads
Post by: kurnal on February 03, 2009, 12:44:27 PM

Welcome back Dave- glad things seem to be working now.

Most aerosol propellants are a mix of butane/propane as far as I am aware.

Title: Re: Effect of test gas/smoke on detector heads
Post by: David Rooney on February 03, 2009, 02:14:40 PM

We did have a problem a couple of years ago using the Black tins on the then newer Gent conventional detectors... absolutely ruined them.

Haven't had any problems since using the white tins....