JJG 780-1992 Chinese Standard -Verification Regulation of AC Digital Power meter

[Kiriakos GR]

JJG 780-1992 Chinese Standard this defines Verification Regulation of AC Digital Power meter

Standard Category: China Metrological Standards
Issued Date:1992-02-15
Implemented Date:1993-01-01
Issued by: The Standardization Administration of the People's Republic of China

As with all national standards you need to buy so to read.
But the most peculiar is that this Standard did not changed or got upgraded ever.
Still active at 2024.

And today Uni-Trend this using it, as proof of compliance for the domestic market of China.

If any reader is able to offer to us, a brief presentation of JJG 780-1992 ? Then please go a head.   

[Kiriakos GR]

Within few hours of heavy duty internet search, I succeed finding the text about this standard in Chinese.
In brief, its about inspection and calibration procedures of AC Digital Power meter,  at 45~65Hz and the required precision of testing voltage and current load.

But hey,  what is this then GB/T 17215-2002 and latest revision ?
https://www.ittsb.eu/forum/index.php?topic=1934.0

I have the impression, that in China mainland there was a battle for years, of whom will be highest in rank standardization organization.
National Institute of Metrology of China VS Government VS others ...

Either way, anyone whom has plans to export Chinese technology in EU, he is obligated to seek compliance according to IEC latest active standard.
Imported technology based at expired standards, this is a huge problem.

The item : AC Digital Power meter
It could be wrongly calibrated   (within EU calibration lab it should inspect three samples and deliver relative verification)
Accuracy specifications might not be tight enough ( Nice looking on paper but not real ).

And finally, this is sales price as new and resale value in the market of used instruments.
eBay and other internet based market places, they are full of used instruments, most of them made under expired standards.
These cannot be used at modern lab, these are good as museum exhibits.