EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: Radec on November 08, 2018, 01:46:51 pm
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Hello, i stumbled upon an online "resistor decade", but I can't seem to recognize what it actually is. As you can see from the pictures there are 6 identical modules. Each has 2 sets of inputs labeled A and V so at first glance I thought they were supposed to be used for Kelvin 4 point measurements, but then I noticed the little switch that switches between them and that each decade is connected to either V or A labeled inputs.
Has anyone seen a decade like this one? What it is used for? Thanks!
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Forgot to include the picture of the switch, sorry :)1
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Perhaps A is for measuring current and V voltage? Check if the A terminals are open when the switch is in the on position and closed when off?
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Regardless of what it does, it seems to be a very attractive looking set.
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I cant tell you exactly why, but it looks like teaching equipment from a school to me.
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Hm, It hadn't occured to me that itcould be a school piece - this is a possible one. I got mislead by the fuse because I'm so used to seeing these kind of fuses on industrial grade equipment... As for trying the switch - i don't actually own the decade yet as I'm trying to figure out what it actually is before byuing it - a ki d of a puzzle. My best bet was that it was a decade for callibrating temperature measurement systems because:
1. It has all ki d of quality check stamps in japanese over it so it must have been used somewhere that needs periodical qc and callibration
2. The range of the decades themselves
The bigger decade is rated either from 0 to 450 ohms or kohms and then a single 500kohm value or just from 0 to 500 kohms. The latter is an ordinary decade, but the first one seems , if memory serves me well, like a range of zero degree celsius thermocouple values. That would also tie to the values of the second decade which go from 0.1 ohms to 1 ohm in steps of 0.1 which seem like the temperature coefficient of a thermocouple per degree celsius. If so then the two decades should be connected in series and then a kelvin measurement using the A and V inputs would be the final piece, but then I noticed the damn switch which switches between them and my speculations went the way of the dodo :). Does any of the above seem plausible?