Re: Dry Cameras

[<jbush@pucp.edu.pe>]

chris

go to radio shack and buy a cheapie humidity reader . . take out the parts
and you have it :]]]]

jamie


On Thu, 11 May 2000, Chris Albertson wrote:

> 
> I asked this question on the list a week or so ago. I wanted
> to know how to measure the dew point.  I figured I'd control the cooling
> water temp to a little over the dew point too.
> 
> The answer I got was simply that the dew point equals the wet-bulb
> thermometer reading.  (Easy to verify this with a glass thermometer.)
> Just put your standard air temp sensor in a wick over a container of
> water.  I think there is a part LMxxx that reads out temp directly.
> 
> > Does anyone know a source for a cheap, not too accurate relative humidity
> > indicator?  I would like one powered by 5 or 15 volts, and which puts out
> > only a modest signal.  The ADC measurement system has a least significant
> > bit of 300 micro volts.  Something with say 3mv or more per % relative
> > humidity would be fine.  I think I can tolerate almost any scale factor
> > that such a device would have.
> > 
> > I would like to sense the relative humidity.  I already sense the
> > temperature.  With the two, I think one can compute the dew point.  I would
> > then regulate the cooling water just above the dew point.
> > 
> > Tom Droege
> 
> -- 
>   Chris Albertson
> 
>   calbertson@logicon.com                  Voice: 626-351-0089  x17
>   Logicon, Pasadena California            Fax:   626-351-0699
>