Hello I am working with a Weston Model 301 DC Voltmeter. The face shows three ranges, yet the back has only two poles. There is nearly full deflection with a 9V battery which seems to indicate I need some kind of resistance or voltage divider network to be able to use it for the 0-600VDC range (which is what I want).

The scales show:
0-10VDC
0-100VDC
0-600VDC

What do I have to do to use this to measure 0-600VDC rather than 0-10VDC?

Thanks in advance for any help.

Ted

Hi Ted

You need a series resistor. The value depends on sensitivity of your meter. If a meter movement is 1 ma the resistor required in 1000 ohms per volt. In this case the required series resistor would be 600,000 minus 10,000, already built into the meter. This would allow 600 volts to read full scale.

Sensitivity of a meter is sometimes marked on the face plate. Someone reading this may know sensitivity of Weston 301 or you could experiment with resistors.

Determine sensitivity of your meter. You know the meter reads 10 volts, full scale. With a 20 volt source determine what value series resistor is required to read full scale. If 10,000 ohms the meter movement is 1 ma. 100,000 ohms, 100 micro amps. (10 volt dropping resistor is already built into your meter.)

Norm

: Hello I am working with a Weston Model 301 DC Voltmeter. The face shows three ranges, yet the back has only two poles. There is nearly full deflection with a 9V battery which seems to indicate I need some kind of resistance or voltage divider network to be able to use it for the 0-600VDC range (which is what I want).

: The scales show:
: 0-10VDC
: 0-100VDC
: 0-600VDC

: What do I have to do to use this to measure 0-600VDC rather than 0-10VDC?

: Thanks in advance for any help.

: Ted