This electronics stuff is difficult

So, I buy a decibel meter. Sound meter, whatever. €20 or so, summat like that.

Great, I can measure noise levels!

Not so fast matey. It needs to be calibrated. 94 dB 1kHz or summat sound source.

Which, apparently, costs €160.

Is there a way around this?

14 thoughts on “This electronics stuff is difficult”

  1. Find someone with a calibrated tester. In a music school, or concert venue probably. Play a fixed tone with a mobile phone.

  2. Bloke in North Dorset

    Without knowing the details the instructions to get it calibrated is covering their arses so you don’t pull it out in court to use as proof and then get your case dismissed because it wasn’t calibrated.

    If you’re intention is to use to make an official case my guess is that it will be close enough to give you a good indication of what you’re dealing with. Take a reading, if it’s well over the environnemental levels you can be fairly confident you’ll be OK if you spend the money to get it calibrated. If it’s close to the line and you’re keen to take measurements you’ll need to get it calibrated but be prepared to be disappointed.

    If you find it’s well below the environmental levels save your money, it won’t be that far out.

  3. Bloke in North Dorset

    Beware of getting in to a circular argument – the sound source would need to be calibrated.

  4. The AudioTools app for iPhone etc is a very good solution, providing all sorts of useful info. They can probably even tell you the likely accuracy.

    The prior suggestion of using what you have and taking further steps if there’s clear cause is very sound. ( ho ho!)

    But if the problem is truly significant, it’s likely that those opposing will claim that not only is your instrument not calibrated, it’s an amateur thing that cannot be calibrated (etc etc etc) plus you don’t know how to use it and the whole thing is an unconscionable attack on an honest business that’s operating within the law etc etc etc

    So if it’s serious and you’re pretty sure you’re in the right, you’ll probably want to consider hiring a professional.

    If on the other hand it’s a problem that’s got out of hand but everybody’s of good heart then wandering over to show them the readings (I’d use AudioTools because you can take screenshots etc) might work fine.

    Best o luck!

  5. It’s not entirely clear whether you bought a decibel meter without realising it had to be calibrated or you are seeking advice before buying one. If the former more fool you. If the latter I can give advice but due to my true free market principles it will cost you.

  6. Does the meter come with a means of measurement from the sound source? If not, the inverse square law will defeat your intention.

  7. Drum’n’bass goes through walls, double glazing cuts road sound quite well.
    So it depends if it’s a nightclub or English tourists are irritating you.
    You could take a reading and film it at the same time to get round the distance problem, but to get rid of the really annoying low frequencies you’d need back up to measure Hertz.
    Rules in Portugal? Have you checked?

  8. Philip

    Most (totally useless) legal limitations on sound are of the form “you’re not allowed to have sound levels above X dB C (peak) at your property boundary”.

    This is of course absolutely effing useless. What’s required is “you’re not allowed to cause sound levels above Y dbC (peak) (or A weighted) in anybody else’s property.”

    Else – as with our neighbours – you can have 40 acres, put out 85 dbA at the boundary, and it’s still 84.5 dBA at half a mile…..

  9. A way around it – sure. Depends on how accurate you need it.

    if you can find a local industrial hygenist they probably have a calibration source they might let you use.

    Otherwise, if there’s a sound source of an already known value you can use that. How well you know the source’s value will be the limits of your calibration accuracy.

  10. Frank
    July 17, 2021 at 6:10 pm

    If the latter I can give advice but due to my true free market principles it will cost you.

    Looks like, in true free market practice, you’re being undercut.

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