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Cheap Noise Meters
fishywick - 12/4/10 at 09:30 AM

I am looking at a noise meter to try and prevent any problems at trackdays.

My Striker passes no problem at 96dba but I am considering some of the Croft low noise days at 88dba with A N other car.

I see there are lots of meters on fleabay for £20 upwards, are they reliable?


boggle - 12/4/10 at 09:43 AM

i had one on my nokia phone...


RichieHall - 12/4/10 at 10:19 AM

Not particularly accurate but....

http://www.maplin.co.uk/Module.aspx?ModuleNo=226470


dhutch - 12/4/10 at 10:39 AM

My housemate (on here also) had a cheapish DB meter (cant tell you the brand/age/cost sadly) but it was 6 db out when held side by side to the one being used on my exhaust at snetterton.

Clearly for comparative work it still works, but certainly it highlights the sort of accuracy you can be working with prehaps.


Danel


Bluemoon - 12/4/10 at 10:55 AM

quote:
Originally posted by RichieHall
Not particularly accurate but....

http://www.maplin.co.uk/Module.aspx?ModuleNo=226470


Good price, just to need to compare it to a calibrated one (or maybe SVA value if that was not long ago)....

Dan


RIE - 12/4/10 at 11:35 AM

quote:
Originally posted by dhutch
My housemate (on here also) had a cheapish DB meter (cant tell you the brand/age/cost sadly) but it was 6 db out when held side by side to the one being used on my exhaust at snetterton.




6dB is a hell of a lot to be out, the exhaust is 4 times louder (or quieter) than the meter indicates


ashg - 12/4/10 at 11:37 AM

i have got this one.

http://www.maplin.co.uk/Module.aspx?ModuleNo=46362

you can get them on the bay for a lot less

have compared it to a proper calibrated cirrus one (same as what they use for iva). both read the same when using the calibration device which is impressive as the cirrus ones are well over £500


fishywick - 12/4/10 at 11:52 AM

As usual, once the research starts, it all gets ever more complicated...

"Its important to note that this sound level meter reports only the ‘C’ weighed total sound level. ‘C’ weighting treats low and high frequencies equally - which you might imagine was just what you wanted do do.
However the ear is not very sensitive to low frequencies and so estimates of noise annoyance normally use the ‘A’ weighted measurement which reflects the ears insensitivity to quiet low frequency sound, sounds like distant trafic noise, air conditioning rumble etc. The Maplin unit doesnt have an A weighting option so you cant really compare the decibel sound levels it gives you with most published tables."

However it seems it may be worth a punt at £20 from what you say. The same meter from Maplin is available on fleabay in both A and B options.


fishywick - 12/4/10 at 11:53 AM

As usual, once the research starts, it all gets ever more complicated...

"Its important to note that this sound level meter reports only the ‘C’ weighed total sound level. ‘C’ weighting treats low and high frequencies equally - which you might imagine was just what you wanted do do.
However the ear is not very sensitive to low frequencies and so estimates of noise annoyance normally use the ‘A’ weighted measurement which reflects the ears insensitivity to quiet low frequency sound, sounds like distant trafic noise, air conditioning rumble etc. The Maplin unit doesnt have an A weighting option so you cant really compare the decibel sound levels it gives you with most published tables."

However it seems it may be worth a punt at £20 from what you say. The same meter from Maplin is available on fleabay in both A and B options.


DM - 12/4/10 at 12:02 PM

I bought the maplin one then took it back when I realised it was no use. At least maplin are good with their refund

brands hatch measured me at 98db, the maplin one said something stupid like 114db

as mentioned, lot of difference between dbA and dbC


BenB - 12/4/10 at 12:14 PM

Not worth it except for relative dB checks IE fit a new exhaust and see if reads higher or lower than before.

Proper dB meters are seriously expensive bits of kit and need regular (and also expensive) calibration....

As said 6dB is quite a lot at the end of the scale we're talking about!!


dhutch - 12/4/10 at 12:39 PM

quote:
Originally posted by RIE
6dB is a hell of a lot to be out, the exhaust is 4 times louder (or quieter) than the meter indicates

Yeah, its stack load.
- Mind you, i was 9db over to start with and got it down with wad load of wirewool...!

A weighted is what you want, should be what all tracks use, afaik. Certainly thats what we used at work for all noise testing of machines.


JonnyS - 12/4/10 at 04:52 PM

Cheap noise meters are useless to be honest. I bought one off eBay for £15 and it measured 110-120db when two 'expensive' meters measured 99db...


bigfoot4616 - 12/4/10 at 05:53 PM

quote:
Originally posted by ashg
i have got this one.

http://www.maplin.co.uk/Module.aspx?ModuleNo=46362

you can get them on the bay for a lot less

have compared it to a proper calibrated cirrus one (same as what they use for iva). both read the same when using the calibration device which is impressive as the cirrus ones are well over £500


i've got one of these, think i payed about £40 for it and used it once.
i've no use for it now as i know i wont pass 98db so i'm sure we could sort something if its any use to you


GavR - 11/5/10 at 12:05 PM

I use my Iphone decibel meter, it was 59p. Dunno how accurate it is becuase I havent had any comparisons but Ive herd Topgear used it on a episode and was complementing it.