Digital Single Phase Power Meter - AC Current measurment Fails due Low P-Factor

[Kiriakos GR]

Currently my most sensitive regarding detection AC power meter, this is Benetech GM86 EU.

GM86 (10A) this has been proven sensitive enough for measuring down to 0.1W but when Power Factor this is at least PF 0.100 and or higher.
Due this observation, I did started a fresh research, and I am now perform testing at the limits of regular EU plug-in power meter  with 16A shunt.

For several months I had the wrong impression, that AC power meter detection this improves when the power meter, this has a shunt for lower ranges.
For example that a 5A shunt this might assist at power meter detection, in comparison to a 10A shunt.

Now I am starting having proofs, that at economy priced power meter, and especially for low current measurement, AC current measurement fails when AC load this has a very small Power Factor.

For example:
230V , 5mA , PF 1.000  (resistive load)    = The low cost instrument will succeed completing a measurement.
230V , 5mA , PF 0.100  (non linear load)  = The low cost instrument will succeed completing a measurement.
230V , 5mA , PF 0.010  (non linear load)  = The low cost instrument will  FAIL detection.

Failed detection this further explained:
We do not know much, of how a low cost instrument, this uses voltage sampling and current sampling along Power Factor detection so this to complete a measurement.
We only assume that voltage and current measurements alone, these are enough so the power meter to perform a calculation in Watts. 

When we have the cheapest EU plug-in power meter 16A, with only three digits for Power Factor, and a poor product documentation, we cannot see the unseen.
The unseen this is actual product limits at Low Power Factor detection.
When Power Factor detection this Fails, the meter will not display AC current at all.

Power measurement sequence this appears to be:
The internal IC (chip) this will start with Voltage detection + Current detection + Power factor detection, and if one of them fails? (due in hardware imitations).
The instrument will display only voltage detection at it LCD screen.     

I am now in the route of DIY, so to make one 47K ohm resistive load, this able to operate safely at 230V, and this be at high Wattage, so this to be unable to overheat.   

[overvolt]

First quick conclusion, GM86 has Power Factor range from 0.100 ~ 1.000 PF.

This is not bad for a Plug-in power meter 

It seems that Power Factor range from 0.001 ~ 1.000 PF, this is a potential of larger monsters.   

[Kiriakos GR]

My current priority, this is the discovery of Plug-in power meter limit's.
Power Factor detection this is assisted when current value this gets higher.

At 133mA the GM86, it can measure down 0.010 PF (but with out owning something as a better comparison point), I am forced to believe of what GM86 it does measure regarding PF.

This week I am going to invest more time at this research.
By this fresh pack of collected experiences, I will earn more knowledge of what conditions will drive any digital power meter to lose PF detection and ACA detection.

GM86 this is not the golden standard, its a low cost training tool.