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wrote:
Grunff wrote:


If I'm going to go down the data logger route, I will probably go for



one of these:
http://www.audon.co.uk/labjack.html

I used one before in a previous project, and found it to be a very


nice

piece of kit.

But that wasn't my question really - I can see how to get the
measurement I want by sampling V and I with a data logger - but I


can't

help wondering if there isn't a cleverer, simpler way, given that all


I

want is total energy.

Another way of asking the question - I can see how to integrate the


data

electronically, after collecting a huge number of data points. But


I'm

wondering if there isn't another way of doing the integration. If


that

makes sense.


--
Grunff



there is, use an opamp integrator. No sampling, along with the errors
that introduces.

NT


haha, yes, nice one. You think that an analog integrator
isn't going to have errors? Especially accumulated over
minutes?

The data logger is the best idea, just record the I&V
waveforms over the period under question then do everything
else numerically.

Cheers,
Mark.