Thanks for the replies — I have all I need except an environmental test chamber to control temp. Of course, right now, I could stick the box outside and drop its temp by 20C — but I really only need a range of 20C +/- 5C. But as it turns out, I have a little portable insulated cooler/heater box for holding drinks and food in the car that has a big reversible Peltier block in it, so maybe I can finesse this temp testing…

Hello, I would use the peltier only in cooling mode and a heater foil for heating. (as you can see in eevblog) One reason is that you have to switch off the peltier for about 5 minutes to cool down before reversing. otherwise it works as a generator and possibly may shoot through your power stage. The other is that its simpler to control the temperature by a PWM heater than with a peltier which needs clean DC voltage for maximum lifetime and efficiency. with best regards Andreas Am 15.11.2014 um 22:48 schrieb Richard Moore: > Thanks for the replies — I have all I need except an environmental test chamber to control temp. Of course, right now, I could stick the box outside and drop its temp by 20C — but I really only need a range of 20C +/- 5C. But as it turns out, I have a little portable insulated cooler/heater box for holding drinks and food in the car that has a big reversible Peltier block in it, so maybe I can finesse this temp testing… > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there.

I use a digital temperature controlled bath for my keeping my standard resistors at 25C. It's versatile since it can do precision temperature/time scans and can easily scan the range your interested in. Right now I have it set to 25.00C with one of my ancient 10K ohm standards. When I first bought my Leeds and Northrup resistors I wanted temperature info on all of them to see if there was an especially good one. I was scanning from 20C to 30C and writing down the resistance values at every 0.1C point. Like Frank mentioned, I went through the temperature range too fast and the data was useless do to hysteresis. Next time I went much slower and the data was OK. My bath has a change in temperature over time function so it will be much easier just to let the 3458A measure continuously and plot the output after the run. I can use Labview to plot the data in real time if I get the urge to "program". Use NPLC = 1000 and OHMSF for best results. Because of my old Leeds an Nothrup reistors I have to use a DELAY of 10S. Most standards don't need this but it's best to compare the resistors value at a Delay of 10S and the default Delay. They should be identical. I use the GPIB data port all the time and can't live without it. Charlie On 11/15/2014 1:48 PM, Richard Moore wrote: > Thanks for the replies — I have all I need except an environmental test chamber to control temp. Of course, right now, I could stick the box outside and drop its temp by 20C — but I really only need a range of 20C +/- 5C. But as it turns out, I have a little portable insulated cooler/heater box for holding drinks and food in the car that has a big reversible Peltier block in it, so maybe I can finesse this temp testing… > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there. > > >