Favour needed for instrument calibration

[Pjdd]

I don't have high-precision measuring instruments and have to rely on the manufacturer's specifications for judging the accuracy of my measurements. There's no place where I can take or send my instruments for calibration.

If someone here has a high-precision instrument(s) and is willing to spare some time to help me out, I'll really appreciate it. To put it in a nutshell:

I'll measure the values of some stable voltage reference such as a TL431 or LM385, a few resistors and capacitors, and send them to you. You will then take your own measurements and tell me the results for comparison with my own measurements. There'll be no need to return the parts.

That's the basic idea. We can go into the details later if someone is willing to help.

 

[KlausST]

Hi,

maybe you should say where you live, or do you want to send the parts around the world?

And: add the measurement conditions: voltage, current, temperature and so on....to the parts when you send them... to get comparable results.

Klaus

 

[E-design]

Maybe you can look at joining a calibration club. You can read about it here. They have some standards that they ship between members.

 

[Pjdd]

Hi,

maybe you should say where you live, or do you want to send the parts around the world?

Yes, I'm willing to send the parts anywhere in the world. In fact, I mentioned that in my first draft but then edited it out. I'm not in a big hurry and can send them by inexpensive ordinary parcel post.

And: add the measurement conditions: voltage, current, temperature and so on....to the parts when you send them... to get comparable results.

I initially drafted my post mentioning exactly those and other details, but then drastically shortened it to avoid cluttering up the opening post.

Another detail: For voltage and resistance, I'd like the measurements to be done with a known accuracy of at least ±0.1% at a resolution of 5 digits. This requirement can be loosened a bit for capacitance if necessary.

I first had the idea of buying 0.1% parts and using them to calibrate my instruments. But I live in a place where it's virtually impossible to order electronic parts online, especially high-precision ones. I found one source that has the LM4040A (the 0.1% version) for the equivalent of about US$1.10 each, but they want a minimum order of 1000 pcs. No sense in spending $1100 on something that will be used only briefly.

I've come to depend a lot on AliExpress.com for parts in recent years and they have the LM4040A for $0.10 each in small quantities, but there'll be no way of knowing if what I get is a genuine A version. They have an excellent search engine but it failed when I searched for 0.1% resistors. It always turned up 0.1Ω, 0.1W or 1% parts.