Temperature stability of model 350

oxphys
New Member

Posts: 1

Temperature stability of model 350 Jan 24, 2020 5:03:01 GMT -5

Quote

Post by oxphys on Jan 24, 2020 5:03:01 GMT -5

Hi,

I'm a postdoctor in a new group in physics department. We are building instruments with He3 refrigerater and dilution refrigerater. We tend to purchase Cernox-1010, model 350 temperature controller and a resistor as heater to control the temperature of the coldest He3/MIX plate, due to requirements of high temperature stability. However, the manual of model 350 discuss temperature stability in an ambiguous way. I don't find some detailed discription about this specs or how to estimate and improve this. Due to the specificity of our experiments, we require temperature to be stable at several hundred and ten mK over several days, so that this specs is crucial for us. Is there any offcial data sheet and suggestions about the temperature stability of model 350?

Thanks.

Lake Shore Jeff M
Lake Shore

Posts: 293

Temperature stability of model 350 Jan 24, 2020 8:05:01 GMT -5

Quote

Post by Lake Shore Jeff M on Jan 24, 2020 8:05:01 GMT -5

As you have observed, the electronic control stability is expressed in Ohms and not in temperature.

The reason is that at any given temperature, the resistance of a NTCRTD sensor is not the exact same value as another sensor. As a result, the temperature control stability needs to be determined on a sensor by sensor basis by comparing the published stability in resistance to the exact sensor you will be using and what excitation and measurement range the sensor needs.

bfang
New Member

Posts: 5

Temperature stability of model 350 Feb 5, 2020 10:31:19 GMT -5

Quote

Post by bfang on Feb 5, 2020 10:31:19 GMT -5

Hi,

please allow me to join the discussion. I agree that stability is better discussed in electrical units, since these are after all electrical measurements. I would like to know then :

- the relation between 1) measurement resolution ; 2) electronic accuracy at 25 deg C ; 3) electronic stability, as tabulated in Table 1-3 of the manual of model 350.
- I see empirically that the electronic stability is twice the measurement resolution, is there a reason ?
- How does that affect the electronic accuracy ?

Thanks a lot in advance.

Best,
Bess