[time-nuts] HP5061B Versus HP5071 Cesium Line Frequencies

jimlux jimlux at earthlink.net
Sun Jun 4 19:42:42 EDT 2017


On 6/4/17 1:49 PM, Donald E. Pauly wrote:
> I own several Fluke 52 stereo thermometers with K themocouples.  They
> run 40 μV/C°.  All thermistors have tiny outputs without op amps.
> They also suffer from self heating.  AD590 sensors give AT LEAST 15
> mV/C° without op amps.  If a regulated 3,000V supply is available they
> can give 2 V/C° into a 1 Watt 10 Meg resistor.
>
3kV?

That's an interesting concept. Better make sure you set your resistors 
up right and keep your temperature range limited, since the max voltage 
across the device is 30V.  And the power supply ripple had better be 
less than 1V (PSRR is 0.1 uA/V at 15V, and 0.5 uA/V at 5V).

What's the tempco of that resistor?

And, you know that the calibration error is +/- 0.5 degree (for the 
better M grade).. Yeah, it's repeatable to 0.1 degree (0.1 uA).








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