I am now the proud owner of a shiny new true RMS multi meter I've seen revues of it on YouTube and it gets very good reviews on all aspects of its accuracy and construction and of course safety not sure if I'm aloud to say which one it is maybe someone will tell me if its ok. Anyhow it reads the same as 2 of my other meters which are also true RMS although I didn't know they where. Any how I've found out that the 2 LED meters I bought that I posted about some time ago are both telling lies although one of them is occasionally telling the truth. It's interesting that the voltage is never still but is usually around 240 and also if I look at around 23:30 it drops off by 3 to 4 volts which must be when local economy 7 kicks in
It is important not to confuse resolution (there are 1000 marks on my metre ruler) with precision (the gap between any 2 adjacent marks is 1mm +/- 0.1mm =10%_, the over-all length may be 1m +/- 1mm= 0.1% )
Digital meters are no different to analogue things like rulers in terms of having an inherent uncertainty, but the numbers sometimes give a false illusion of accuracy.
Even a poor meter can tell 220 V from 240, which in many cases is enough.
What is the guaranteed accuracy spec on the 'lying' meters?
It is important not to confuse resolution (there are 1000 marks on my metre ruler) with precision (the gap between any 2 adjacent marks is 1mm +/- 0.1mm =10%_, the over-all length may be 1m +/- 1mm= 0.1% )
Digital meters are no different to analogue things like rulers in terms of having an inherent uncertainty, but the numbers sometimes give a false illusion of accuracy.
Even a poor meter can tell 220 V from 240, which in many cases is enough.
What is the guaranteed accuracy spec on the 'lying' meters?
