Soo.. do I need to send my new resistors already back to PTB for recalibration?

[mzzj]

Got a slightly used standard resistor set..




 

Need to wait couple of years to calculate 100-years stability for these 

[Henrik_V]

Very nice one
Next year (2020) will be the next puplic day at PTB, usually in September.  It's every 2 years, so 2024 will match 
Pretty shure you will get at least some values in this case.

[mycroft]

You missed the 1.69 ppm change from 1990. Wait a little bit longer to not miss this year's change of -17 ppb 

[Conrad Hoffman]

Don't forget the 1948 change- https://www.nist.gov/sites/default/files/documents/calibrations/87mscohm.pdf

That's fairly noticeable when having old resistors certified in a modern cal lab.

[babysitter]

Just want this thread subscribed.

[HighVoltage]

How did they measure 0.000 099 99 in 1924?
Impressive!

[The Soulman]

Don't forget the 1948 change- https://www.nist.gov/sites/default/files/documents/calibrations/87mscohm.pdf

That's fairly noticeable when having old resistors certified in a modern cal lab.

That was the NBS (national bureau of standards, USA) Ohm that changed (490ppm) to better match the SI (systeme international) Ohm.
Basically, the USA got it wrong and the pre 1948 was 490ppm to low.
This Reichsanstalt resistor was likely unaffected by this.

[Henrik_V]

My eyes are old, and the picture not that clear.
Do the calibration report and the resistor match?
I read 36/1924 on the cal mark on the resitor (38/1924 in report)
and the serial number looks close but the last digit seems 0 (1656740?? )
and the 10 isn't for 10 Ohms?

[mzzj]

My eyes are old, and the picture not that clear.
Do the calibration report and the resistor match?
I read 36/1924 on the cal mark on the resitor (38/1924 in report)
and the serial number looks close but the last digit seems 0 (1656740?? )
and the 10 isn't for 10 Ohms?

You are right. I didn’t get  the original! certificates yet and the example photos are not even from matching set. What really amazed me was that the original 1924 cal certificates were still together with the resistors.

[Henrik_V]

What really amazed me was that the original 1924 cal certificates were still together with the resistors.

Well, one major value of a calibration artifact is his known history. So you try to keep both together.