[time-nuts] Any experienced HP 2804A thermometer users out there?

David Forbes dforbes at dakotacom.net
Sat Jan 24 11:43:56 EST 2009

At 10:42 AM -0500 1/24/09, John Ackermann N8UR wrote:
>The temperature probes for the 2804A quartz thermometer seem primarily
>intended for liquid immersion.  I'm looking for practical tips on how to
>couple the probe to a solid surface (e.g., a PC board) for accurate
>temperature measurements of the surface.
>Anyone know the best way to do this?


What aspect of your measurement requires which amazing property of 
the HP temp probe?

As others have said, matching the sensor to the thing to be measured 
is of prime importance. Therefore, using the HP crystal probe on a PC 
board is not an optimal solution.

I had to do PC board temperature monitoring a few years ago, and 
found that I could get very good resolution with the Minco RTD 
sensors that come attached to a small piece of Kapton tape.


I used a National Instruments data acquisition system. The system was 
able to measure temperature changes down to about 0.01C with 

You would need to calibrate the sensors against a standard if you 
want accurate temperatures. They recommend an ice bath for that work.


--David Forbes, Tucson, AZ

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