Re: Analogue to Digital Multimeters
Yes, you need to add a resistor across the lead.
The voltage measurements quoted on data sheets will be of the form " Readings taken on the 250V range of a 20K/Volt meter " .
This means that the meter should look like a resistance of 250 * 20K =5MOhm (call this 'X'). Now you need to find out the impeadance of your digital meter on the appropriate voltage which should be in its manual. No idea what the value would be but lets pretend for the moment it is 20MOhm (call this 'Y').
Take the product XY = 20 * 5 = 100
Take the difference X-Y = 20 - 5 = 15
The paralell resistor you need is the ratio of the two = 100/15 = 6.67MOhm.
If you dont have the meter's manual, and don't have a second meter that can measure the digtal meter's resistance then this can still be worked out using loading effect - will explain if needed.
TTFN,
Jon
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