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Subject: Re: Calibrated Thermometers

"Richard Knoppow" wrote:
> B&W needs better than +/- 2F for good control. Look at
>the temperature increments on the Kodak developing charts,
>they are 2F and the time difference is significant.

That is precision though, not accuracy. It could be 2 degrees
off and all will work fine if it is *always* 2 degrees off.

But if it is off by 2 in one direction today and off by 2 in
the other direction the next time... *ouch*.

> Last time I looked body temp was 98.6F.

Or, maybe not! (If I have a temperature that high, I'm *sick*.)

Seems that 98.6F was arrived at by averaging a number of
temperatures measured only to 1 degree, not to 1/10th of a degree.
When done more precisely, the value seems to be 98.2F.


Regardless, that isn't the "body" temperature either! It's an
"oral temperature", and the actual core body temperature is not
only different, but varies from one person to another (by up to
4.8F) and for an individual during the course of a day (1.09F).


Looks like if we calibrate the darkroom using body
temperatures... we'll under develop in the morning and over
develop in the afternoon... :-)

Floyd L. Davidson
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com


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