Earth Fault Loop Impedance testing on socket-outlets

So this is a ze test?

If I will use RCBO 6amp for lighting circuit. Then how I will do ZS .

I see its old video and tester is 1720. Remember using it myself and I would never go by low test accuracy testing Zs on a cct with rcd.. its not accurate at all.. tester gives different reading every test. Now I'm using 1741 which actually shows if reading is accurate and from experience using it I can tell its pretty good. If people have older testers the only 1 way of doing it properly is dead test. No point even trying low test on rcd circuit. Also would you be changing every socket is they have 0.2ohm difference between points, but still passing zs?

Totally believable. KT63 overcomes this automatically.

Would a reading here of 0.44 indicate the Zs value? (Ze+R1+R2)?

As long as the readings were within the permit tolerance of BS 7671, would it really warrant a socket change if the impedance in one socket was different from the other?

I cleaned the earth pin of my fridge and changed the socket to another room via an extension. When the thermostat turns off the fridge, it also flickers my monitor off and back on. My PC monitor is on a separate breaker ring also. Maybe the interference is the fridge relay not a poor Earth? Thanks for any help.

Why when we determine Zs by measurement, are we not required to remove parallel earth paths. Surely this means we get a different result to the calculation method (Ze +R1 + R2)

what would be the next step if a circuit didn't meet max zs for example a tns or tncs?

good job you dont use a Fluke, you'd get that all the time,lol