[CAUT] Hygrometers

[Kent Swafford]

These consumer hygrometers do not provide scientific accuracy, but
they sure seem good enough to me.

I use an older version of this: (Translate; I bought when they were
more expensive.)

http://tinyurl.com/2ofyd2

In a grand piano with a climate control system, I have one of these
hygrometers on a shelf across from the piano; one remote sensing unit
is below the soundboard of the piano, and another remote sensing unit
is in the piano above the soundboard. (The piano has both bottom and
top covers.) The hygrometer set-up gives a rather dramatic
demonstration that the climate control system is working; it is a very
comforting thing to know that when the room RH is low 70's that the RH
in the piano can still be in the high 40's. This can provide very
strong evidence of the efficacy of piano climate control systems.

Kent Swafford


On Nov 16, 2007 8:07 AM, Paul T Williams <pwilliams4 at unlnotes.unl.edu> wrote:
>
> Hi Jeannie!
>
> Good to hear from you!
>
> That's an interesting observation on the cheapie vs. fancy-schmancy.  Maybe
> that "relative-relative" reading is all that I need.  I still don't
> understand why that one particular room feels so muggy, yet doesn't register
> high on the hygrometer.  Maybe I have a lemon?
>
> Best,
>
> Paul
>
>
>
> "Jeannie Grassi" <jcgrassi at earthlink.net>
>
> Sent by: caut-bounces at ptg.org
>
> 11/15/2007 09:23 PM
>
> Please respond to
> College and University Technicians <caut at ptg.org>
>
> To"'Ed  Sutton'" <ed440 at mindspring.com>, "'College and University
> Technicians'" <caut at ptg.org>
>
> cc
> SubjectRe: [CAUT] Hygrometers
>
>
>
>
>
>
>
>
> Hi Ed, Paul, et al,
> I recently bought one of the "Professional" hygrometers from Pianotek
> because I had heard the same comments from several other people.  Well, for
> the past two months I've been using it side by side along with a
> Dampp-chaser hygrometer a/o ones that my clients happen to be using.  I'd
> like to say that the small difference in RH that it reads hardly amounts to
> anything.  AND……it takes quite a while (like five minutes) to settle down
> and give an accurate reading from what it registered in my case, in my car,
> traveling from the last appointment.
>
> At first I would smugly take a reading off of it immediately and was
> surprised at what a different result it gave from what was in the piano.  I
> congratulated myself on upgrading my tool and being a true "professional.
> However, one time I just let it sit there while I was tuning and noticed how
> much it changed until it ended up with almost the same as the one in the
> piano.  I observe this every day now.  And I'm asking myself why I spent all
> of that extra money.  One client proudly showed me his thermo-hygrometer
> (with memory) that he bought at Walmart for $6.  It read the same as my
> fancy-schmancy "professional" one.
>
> Comments?  ;>)
> jeannie
>
>
> ________________________________
>
> From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of Ed
> Sutton
> Sent: Thursday, November 15, 2007 3:05 PM
> To: College and University Technicians
> 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"
>