Keysight U1272A EMC Issue this does not influence industrial electricians

[Kiriakos GR]

Agilent U1272A multimeter this is well known to ITTSB Blog among it brother model U1273A.
I wrote lengthy product reviews about both of them in past five years and I did use them in hundreds of real applications, and they never fail in any of them.

Recently there was users reports that there is an EMC issue with them, and ITTSB Blog this did it own research so I as professional electrician to discover true impact of this issue in electrical applications.

ITTSB Blog testing this shown that square wave signal from about 600 KHz and higher this starts influencing displayed measurement stability at Ampere input and also at mV AC measuring range.
By the help of PHILIPS PM5134 Function generator I did manage to discover that 10 MHz this is frequency causing highest parasitic phenomenon.
Above 10 MHz (square wave), parasitic phenomenon this decreases.

Because square wave this it does exist in low-end or low-cost inverter, I thought to perform some testing in real conditions.
Cheap ups systems them working at 50Hz, variable frequency drives them working up to 400Hz and identical frequency this is used at high-power IGBT them serving in aviation systems.

Our test bed this is very simple, this includes worst ups inverter in the market, and this is true square wave output at 220V / 380W Max.
Output this is a great signal full of harmonics as bonus.
Test load this is 150W incandescent lamp.
U1272A this tested at measuring current in series with the load.

When I finished with all testing, now I am aware that EMC fresh discovered issue this has no impact at all in applications them related to field work of professional electrician.

Agilent – Keysight they did respond to such complains by an offering of replacement meter.
According to their announcement it will be available soon a redesigned U127X meter.
I am currently unable to imagine in what above text this actually translates to.
For example if a user returns a U1272A he expects getting back another U1272A and not a random meter from this product series.
And the same goes for anyone returning an U1273A (OLED).

After several years of Blogging, I am now aware that some news they are mostly about creating an impression.
According to my experiences I will say that your U127X multimeter, this has 100 KHz max measuring bandwidth and therefore this is excluded from RF applications by design.
From the other hand, as far I am aware of there is no RF sources them polluting range of 1 to 10 MHz by transmitting by using square wave.
Square wave this is noisiest signal this causing very strong harmonics, compared to sine-wave.   

Therefore the all story while its true, it that rare this to become a problem, as is equally rare you seeing a ghost. 

Personally I did fill up this online form for returning back just the U1272A but for another reason, and this is that it Low Pass filter this is softer than expected speaking of frequency cut off (unwanted frequencies’ filtering).
https://www.keysight.com/main/editorial.jspx?cc=US&lc=eng&ckey=2806392&id=2806392

Bellow there is two pairs of pictures:
First pair includes measurements’ of 220V Mains by oscilloscope and also U1272A measuring current.
Second pair includes measurements’ of ups at about 210V dirty output by oscilloscope and also U1272A measuring current.

All measurements’ are quite normal and there is nothing more for me to say.