[CAUT] Hygrometers

[Paul T Williams]

Are the sling style the ones one would whirl around your head on a string? 
 Richard had one of those, but accidently broke it in the shop years ago 
and hasmet had to be called in for the mercury clean up.  I wouldn't want 
those.  The Cooper looks interesting...

We do have extrememely dry conditions in the cold Nebraska winters, and 
very high humidity in summers; but the facilities across campus opens a 
steam duct system that goes to every building on campus, I don't think 
there is much adjusting that can be made.  It's either on or off.  Very 
old and antiquated.  We're working on getting a new building someday (pipe 
dream, of course ;>)

Thanks

Paul




"Ed  Sutton" <ed440 at mindspring.com> 
Sent by: caut-bounces at ptg.org
11/15/2007 05:23 PM
Please respond to
Ed  Sutton <ed440 at mindspring.com>; Please respond to
College and University Technicians <caut at ptg.org>


To
"College and University Technicians" <caut at ptg.org>
cc

Subject
Re: [CAUT] Hygrometers






How about the "Professional" meter that Pianotek sells?
I like it because it reads quickly and reads lower RH than the Radio Shack 
types.
I haven't compared it to a sling psychrometer. The sling psychrometers I 
have found were rather expensive.
Ed Sutton
 
----- Original Message ----- 
From: John Musselwhite 
To: College and University Technicians 
Sent: Thursday, November 15, 2007 4:41 PM
Subject: Re: [CAUT] Hygrometers

At 12:42 PM 11/15/07, Paul wrote:

Hi List, 

I have a couple of those cheap  max-min thermo-hygro readers from 
Pianotek.  I'm not sure if they're very accurate. 

They're more accurate than the Radio Shack ones, but I don't think by 
much.

If you all remember, last fall/winter I sent in some photos of one of our 
recital rooms that Richard West took before I got here with the fog and 
water dripping all over everything.  It hasn't been that bad since I've 
been here, but the last couple of times I've gone in there this past week, 
it feels really muggy, but the hygrometer only registers 40-45% (which 
would be ideal).  Any suggestions on who makes a real accurate reader? 

We have the opposite problem here where Rh can be down into the single 
digits in mid-winter. None of the "standard" humidity gauges go down that 
far. I use a Cooper Digital Psychrometer much like the one down the page 
at http://www.techinstrument.com/acatalog/Hygrometers__RH___humidity_.html 
  (SAMJR995). It's a digital version of a "sling psychrometer", the 
wet/dry bulb unit we use to make truly accurate RH readings. While it's 
supposedly accurate +-5% it still reads down to zero Rh which in worst 
case might actually be 5%. I've read as low as 3% in mid-winter here in 
some churches. In those pianos with DC's installed, sticking it under the 
rim for a minute and pressing the "hold" button shows it's in the 40-43% 
range at the soundboard even with extremely low humidities outside the 
instrument.

I also have a USB recording hygrometer that will track the RH and temp 
over a long period of time. It's at 
http://www.measurementcomputing.com/cbicatalog/USB-502.asp?dept_id=414&pf_id=1759 
. It reads very much like the "standard" units and differs from the 
Psychrometer's readings. I trust the Cooper more for truly accurate 
readings.

                 John

-------------------------------
John Musselwhite, RPT  -  Registered Piano Technician
Musselwhite Piano Services - Calgary, Alberta Canada
Office/cel (403) 246-7717 Fax (403) 255-5268
Outside of Calgary call Toll Free:  1-866-95-PIANO (1-866-957-4266)
"Three Generations of Experience"
-------------- next part --------------
An HTML attachment was scrubbed...
URL: https://www.moypiano.com/ptg/caut.php/attachments/20071116/2fc14bd6/attachment.html