Humidity Gauges, etc.

[John Minor]

      I don't know what all the fuss is about accuracy of humidity
gauges. The owners manual with my Bacharach (No, NOT Burt!!) Sling
Psychrometer says:

      "In addition to the above instructions, barometric pressure and
other factors will influence exact relative humidity determinations to a
very minor degree. For precise work, use psychometric chart or set of
table such as W.B. 235 'Psychrometric Tables for Obtaining the Vapor
Pressure, Relative Humidity, and Temperature of the Dew Point' which can
be purchased from Superintendent of Documents, US Gov. Printing Office.
However, accuracy of the Psychrometer is satisfactory for all except the
most exacting work."

      For our type of work, it's only really necessary to have an
approximate humidity reading. After all, it will change with the temperature!

      This reminds me of the first time I owned a decent watch, with a
quartz crystal. I had access to the railroad phone number with ACCURATE
time.  It said: "At the tone 4 hours 22 minutes coordinated universal
time". I took it to the jewelers and told them it gained time. They asked
how much time, and I told them 1.5 seconds a month!!! I could tell by the
expression on the jeweler's face I was in for a long and frustrating career
as a "perfectionist"!


     "If football players were armed with guns, there wouldn't be
            stadiums large enough to hold the crowds."--Irwin Shaw
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      jminor@uiuc.edu//John Minor//University of Illinois