Calibration

[Spawn]

True, but before I do that there must be something really wrong with them, till now even oldest one is equal to the newer ones, only Fluke 112 is litle bit of on DC current.

[saturation]

To spot check your meters all you need is a stable high end value for each range, or better yet a low and mid range too.  That's usually where the deviation is greatest, i.e., full scale.

https://www.eevblog.com/forum/projects/poor-man-calibration-facility/

[jucole]

About calibrating, I got around 25 multimeters : 11 Flukes some of them are bench type, 4 Gossen Metrawatts, 2 Voltcrafts, 2 Philips amm’s, a Thrulby bench mm and some pocket dmm’s.

 If I send them out for calibration I would be poor by now, but the plus side is I can compare them together, which I do quite often, every 3 months I check all the batteries in my multimeters..

Surely you'd be poorer buying 25 multimeters and keeping them in batteries than just getting a calibration for your best meter?   You know, if you get any more Flukes you could open up you're own Fluke Multimeter Museum! 

[Spawn]

lol yeah some of them can directly go to museum like 30+ years old ones