Re: Resonant mirror noise

Posted by Martin Wessendorf-2 on
URL: http://confocal-microscopy-list.275.s1.nabble.com/Resonant-mirror-noise-tp7588458p7588470.html

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Dear all--

I'm going to guess that the obnoxiousness of the sound may be a
function, in part, of the age of the listener.
See: https://link.springer.com/article/10.1007/s00420-014-0951-8

--Along those lines, I once had a digital watch with an unusually 
high-pitched alarm that I (at age 60) could barely hear, but the sound
of which drove my sons (in their 20s) crazy.

Martin Wessendorf




On 7/25/2018 9:33 PM, Power, Rory wrote:

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> Hi Mike,
>
> Thanks for your reply. I was rather referring to an 8 kHz fundamental oscillation. The noise is quite unpleasant - I’d hate to hear the 4 kHz if that’s worse as you say.
>
> Isolation should be possible. Perhaps combined with some foam we’ll arrive at a workable system.
>
> Yes, I assumed the same. Thanks again.
>
> Regards
>
> Rory
>
> …………………………………………………………
>
> Dr. Rory Power
> HFSP Postdoctoral Fellow
> Morgridge Institute for Research
> Medical Engineering | Huisken Lab
> 330 N Orchard St, Madison, WI, 53715
> Tel: [phone]
> [hidden email]<mailto:[hidden email]>
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>
>
>
> On Jul 25, 2018, at 21:18, Michael Giacomelli <[hidden email]<mailto:[hidden email]>> wrote:
>
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>
> Hi Rory,
>
> 8 KHz unidirectional or bidirectional (so 4 KHz fundamental)?  The 8 KHz
> scanners are usually not that bad even at maximum amplitude because the 8
> kHz tone is a lot harder to hear and essentially all the harmonics are out
> of audible range.
>
> For 4 KHz at larger deflection angles you either need hearing protection or
> to really isolate it from the room.  A metal box around the scanner and a
> window on the input port so that air cannot pass in/out of the scanner
> helps a lot. This is how most commerical systems work.
>
> I don't think the model matters; the noise comes from pushing air, so for a
> given mirror size and deflection angle the noise power is going to be
> almost constant.
>
> Mike
>
> On Wed, Jul 25, 2018 at 9:03 PM, Power, Rory<[hidden email]>  wrote:
>
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> Hi Confocalists,
>
> We’re trying to circumvent the annoyance of resonant mirrors screaming at
> 8 kHz. I was wondering whether anyone has a recommendation for constructing
> soundproof containment?
>
> Generally were using inexpensive resonant mirrors from EOPC:
> http://www.eopc.com/sc30.html
>
> Also, does anyone know whether the more costly resonant scanners used for
> confocal/multi-photon laser scanning microscopies are any better in this
> regard? Were not hugely concerned with other attributes (simply for light
> sheet microscopy stripe suppression) just the piercing noise.
>
> Many thanks in advance!
>
> Rory
>
> …………………………………………………………
>
> Dr. Rory Power
> Morgridge Institute for Research
> Medical Engineering | Huisken Lab
> 330 N Orchard St, Madison, WI, 53715
> Tel: [phone]
> [hidden email]<mailto:[hidden email]>
>
>
>
>
>
>

--
Martin Wessendorf, Ph.D.                   office: [phone]
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