thx michael. That's exactly the problem. I did wrote the excel macro like what you were suggesting, but the rms voltage reading(or even the average) obtained from the data points will produce a fluctuating readings which is more than 5%.
If you don't get what I am trying to say, try measuring a calibrated voltage source.
When you read the voltage using the Picoscope 'meter' reading, you will get almost a constant value all the time say 5.75 volts over the period of say 3 minutes. But that's not the case when we try to get the values from excel data. say now the excel say the voltage is 5.89volts when the 'meter' says 5.75volts.
If I turn the voltage source off and put it back on, the 'meter' will still say 5.75 volts. No fluctuation. But if I import the data points to excel, alas, the voltage is now 6.12. turn it off and on again and the reading now maybe 5.4 volts, while the 'meter' in Picoscope still display the same values, no change or fluctuation whatsoever.
What I want to know is how the software in picoscope 'meter' maintain to keep the value constant. I intend to adopt the method in excel.
If the readings is not repeatable like what has been displayed on the 'meter', I might as well chuck the ADC212 to the bin. There must be a way to do this, I believe.
There must be a shrink in your company who design the software who can explain all this abnormalies.