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Electrical Metrology | Measurement Tips & Products | Calibration standards => Electrical Metrology for enthusiast => Topic started by: Kiriakos GR on January 25, 2020, 11:29:44 AM

Title: Vishay VHP203 0.0023% resistor a travel at minus 20 Celsius and back at 15C
Post by: Kiriakos GR on January 25, 2020, 11:29:44 AM
Few years back I did receive one Vishay VHP203  0.0023% 500R which was not at actual specifications.
The arrived resistor was at 500R but minus 0.004%  and therefore I did request an replacement which I did receive.

Even so this superior resistor where unused for several years and now that I am at making a new set of calibration test accessories, I am going to use it. :)

VHP 203 product Series this aiming metrology applications, operating range this is minus 50C up to 150C.
I has full of curiosity of what will change if I misused a bit  :)  by sending it to minus 20C for 12 hours.

I did use my 8846A so this to monitor the defrosting period for 2H 30 minutes.
The resistor recovered back at 15 Celsius environmental but true temperature this is 18C because this 8846A this is a source of heat, and part of the heat escapes from the banana plugs.

I have just taken few pictures to share and I will complete my mathematical evaluation later on. 
Title: Re: Vishay VHP203 0.0023% resistor a travel at minus 20 Celsius and back at 15C
Post by: Kiriakos GR on January 25, 2020, 12:15:26 PM
While this story started as Vishay VHP203 benchmark, now it is required of me at bench-marking the 8846A with one of the finest resistors (regarding quality) of our planet.  8)

First new exploration point this is Standard Deviation at 15C for a few minutes.
This is an interesting test for  the 8846A so to discover it internal noise & sensitivity.

While 8846A this is documented as 6 1/2 DMM,  the Stats has 7 1/2 resolution, and SD measurement this collects data from 8 1/2 measuring resolution.
First visual analysis makes known that there is 180 uOhm that is close to 1/5 of a single milli-Ohm.