I was studying avometer, and came across this paragraph which I find

[uzair_ha91]

I was studying avometer, and came across this paragraph which I find confusing: "The voltage measuring part of the avometer is actually a multirange voltmeter. It consists of a number of resistances each of which can be connected in series with the moving coil galvanometer with the help of a switch called the range switch. The value of each resistance depends upon the range of the voltmeter which it controls..."
I thought that the resistances make up the range, so why does it say that their values depend upon the range? What range are we talking about here? Please clarify...

 

[Darryl]

Im guessing, but I think they would be referring to the FSD for full scale deflection current of the moving coil galvanometer.

The series resistance will scale it's current based on I = V/R. V is the measured Voltage, and R is the total resistance of the moving coil galvanometer and the range resistance value.

This brings up the term "Ohms per volt" which is a measure of "goodness" of (mainly) analogue meters.
The AVO is a classic instrument rugged and accurage and a pleasure to use.