Re: Good humidity meter?

[Richard Knoppow <dickburk@ix.netcom.com>]

----- Original Message ----- 
From: "Ken Sinclair" <photo1@telusplanet.net>
To: <alt-photo-process-l@usask.ca>
Sent: Sunday, June 29, 2008 2:06 PM
Subject: Re: Good humidity meter?


> Sam,
>
> I was taught those many years ago that the most accurate 
> measuring of  humidity was by using a
> sling psychrometer....  to measure the humidity at the 
> time of  measurement, rather than a over
> a period of time.
>
> They can be purchased somewhat inexpensively at auction
>
> eg.
>
>
> http://cgi.ebay.ca/Weksler-Hygrometer-Sling-Psychrometer- 
> in-
   My sling psychrometer cost about $30 but that was some 
years ago. It came with a simple slide-rule for calculating 
the RH.
   The dry bulb thermometer can be used for calibrating the 
cheap dial thermometers found in "weather stations".
   Most of the cheap hygrometers are adjustable but are 
very slow in response and not very accurate at the ends of 
the range. You can adjust them using the psychrometer and at 
least get some idea of the trend of RH.

---
Richard Knoppow
Los Angeles, CA, USA
dickburk@ix.netcom.com