sorry for the delay in replying been a busy day.
Firstly what happened at 20:42 i dont know i was out (honest guv
) could have been neighbour/s on the same phase ??
FYI House is a basic PME single phase supply, 100A fuse, housing estate lots of bungalows.
Here as promised is a 24 hour graph (nearly 24Hrs
Due to the graph above being compressed HERE are the results in EXCEL format
if you want to do your own expanded graph.
Andy - yep idle usually around 244.5v, i compared the cheap meter with my main one (Seward Combi-Compac) and its pretty well much bang on.
Trumpy - as for power quality measurements, i was speaking to a local Amusement arcade owner a few months back when i went to repair some kiddy rides, and he was telling me that he had got onto the Electricity board a few years ago because his bandits/fruit machines were continually breaking down, they fitted a graph recorder to check voltage for a few days and the guy did say the voltage at peak times was too low. As i said this happened a good few years ago and the owner didnt go on to say what happened, but i recon the mains cable would have been upgraded, because he still has got a lot of old machines still running.
Anyway im happy with my new meter, and wont bore you all with more graphs.