Dampp-Chaser hygrometer specs

John Ross jrpiano@win.eastlink.ca
Tue, 25 Jan 2005 14:42:19 -0400


I should have added the word sling.
It is a wet and dry bulb thermometer that you spin. It comes with a slide 
rule, and tells you the relative humidity, by comparing the dry thermometer 
reading, with the wet one.

John M. Ross
Windsor, Nova Scotia, Canada
jrpiano@win.eastlink.ca
----- Original Message ----- 
From: "Greg Newell" <gnewell@ameritech.net>
To: "Pianotech" <pianotech@ptg.org>
Sent: Tuesday, January 25, 2005 2:28 PM
Subject: Re: Dampp-Chaser hygrometer specs


> Uuuuummmmmmm, what's a psycho - motor? Does this detect psychos?
>
>
>
>
> At 01:15 PM 1/25/2005, you wrote:
>>Hi Roger,
>>If a person has a psychomotor, is there a way to change the hygrometer to 
>>agree. That way, we could check and calibrate them, periodically?
>>Regards,
>>John M. Ross
>>Windsor, Nova Scotia, Canada
>>jrpiano@win.eastlink.ca
>>----- Original Message ----- From: "Roger Wheelock" 
>><roger@dampp-chaser.com>
>>To: "Pianotech" <pianotech@ptg.org>; "College and University Technicians" 
>><caut@ptg.org>
>>Cc: "Becky Baldwin" <becky@dampp-chaser.com>
>>Sent: Tuesday, January 25, 2005 2:01 PM
>>Subject: Dampp-Chaser hygrometer specs
>>
>>
>>>Hello list,
>>>
>>>I have received a few inquiries regarding the accuracy of Dampp-Chaser 
>>>hygrometers.  Customers have purchased the units in quantity, set them 
>>>all up to run side by side, and then have become concerned about the 
>>>results. We contacted the manufacturer in Sweden and they verified the 
>>>following information.
>>>
>>>Measuring range:  20-95%RH
>>>Accuracy within 50-70%RH: +/- 3%RH
>>>Accuracy outside 50-70%RH: +/- 5%RH
>>>
>>>I find that these specs are typical for hygrometers priced similarly to 
>>>ours.  Unfortunately, 42% RH could be read anywhere from 37%RH to 47%RH 
>>>when read with these instruments.  We believe, however, that the 
>>>instruments do measure changes in relative humidity quite accurately.  We 
>>>had hoped technicians would use them to show piano owners the variations 
>>>in the piano's environment (maximum versus minimum readings) rather than 
>>>use them as scientific instruments.  I use either data loggers or high 
>>>end ($1500 plus) hygrometers in my research.  The old saying, you get 
>>>what you pay for, is really true for hygrometers.
>>>
>>>Another thing I occasionally do is find myself questioning the reading 
>>>only to realize a little later that it was set on either the max. or min. 
>>>I feel pretty dumb when I figure this out, but thought I would pass it 
>>>along just in case.
>>>
>>>Thanks,
>>>
>>>Roger
>>>
>>>
>>>
>>>
>>>
>>>_______________________________________________
>>>pianotech list info: https://www.moypiano.com/resources/#archives
>>
>>
>>_______________________________________________
>>pianotech list info: https://www.moypiano.com/resources/#archives
>
> Greg Newell
> Greg's piano Forté
> mailto:gnewell@ameritech.net
>
> _______________________________________________
> pianotech list info: https://www.moypiano.com/resources/#archives
> 



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