"allanc" wrote in message
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On Oct 11, 8:00 pm, "Charlie" wrote:
"allanc" wrote in message

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A friend installed a Honeywell 5+2 Digital Thermostat last weekend.
The inside temperature reads 68 and I am trying to check its accuracy.
I compared it to two free standing digital thermometers which I
balanced on top of the thermostat (at the same time).
The thermometers readings range from 69 and 71; to 71 and 71.
Any suggestions on determining the *right* temperature are
appreciated.

Thank you in advance.

For openers make up a mixture of ice and water. Before the ice is all
melted
check the water temperature. 32F right?

With a normal household thermometer you won't be able to check the boiling
point, but the cold test will tell you if the glass is in the right
position
against the scale.

One of the digital thermometers ranges from about 66-86.
I do not know about the other.
Are you suggesting that I submerse the other?
I have no idea if it is waterproof.




Sorry I was thinking of a glass tube thermometer, that is, an analog device.

The trouble with digital is the rounding error. On analog you might read 70
and a half.
But one digital might sense it as 70.45 and report 70 and another might
sense 70.55 and report 71.

This is exactly why I bought a glass thermometer just to check my digital
thermostat. They are less than $5.
Then if you really want to make yourself conused, take the room temperature
in various parts of the house.

Charlie