At 06:00 AM 3/5/2008, Richard Benfield wrote: >PS I'm sure the LEM ones are nearer 1% The LEM current sense modules are freaking accurate. They are also Hall-sensor based, but as part of a closed-loop servo. Hall sensor linearity is completely a non-issue with the LEM parts. They have a gapped ferrous (metal) loop that the conductor passes through. There is a solenoid coil that the loop passes through, with a linear hall sensor in the middle of the gap. An op-amp causes current to flow through the solenoid coil such that the field from the coil balances (cancels) the field from the conductor(s) passing through the loop. The current needed to balance the field is made available on the output pin. Although the LEM modules are good down to DC, I've only ever used them for measuring AC current. As such, I have NO idea if the DC zero point shifts with temperature or not - its just not been important for us. dwayne -- Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax www.trinity-electronics.com Custom Electronics Design and Manufacturing -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist