How to test a 4-20ma output with limited tools

[Mrnicks]

I have a device that puts out a variable 4-20ma's to another device. I don't have the device to connect to it. So I need to test the functionalitly of the output with a multimeter without a load. Obviously I need something to put the meter in series with. What can I do here? Resistor?

 

[ericgibbs]

I have a device that puts out a variable 4-20ma's to another device. I don't have the device to connect to it. So I need to test the functionalitly of the output with a multimeter without a load. Obviously I need something to put the meter in series with. What can I do here? Resistor?

hi,
Just connect the meter on mA's in series with loop.
It should read the loop current.
Whats the device outputting the 4 to 20mA.?

 

[Mrnicks]

It's a magpwr versatec tension controller. It's puts out to a current to pressure transducer.

Your advice did work by the way. I actually tried that first but being in a hurry i think i had the meter in ac not dc. Duh! Thanks for your input.

 

[Boncuk]

Connect a standard burden resistor of 500Ω to the current source. The resulting voltage drop should be 2 to 10V (starting at 4mA to 20mA)

Boncuk

 

[Analog]

Nothing needed except a meter. Put it on current setting.

 

[Leftyretro]

4-20ma transmitters come in two varities, 2 wire and 4 wire. 2 wire is the most common.

If 2 wire then the device requires a power source (usually 24vdc through a 250 ohm resistor) to power the sensor so that it can then regulate the loop current according to it's sensor measurement. You can measure the value by either reading the voltage drop across the 250 ohm resistor (0% = 1vdc, 100% = 5vdc) or by measuring the loop current with a milliamp meter by wiring it in series with the loop wiring.

If the device is a active 4 wire transmitter then one can read the measurement current by just hooking up a milliamp meter across the the two loop output terminals. The other 2 terminals are wired to a DC or AC power source as specified by the specific transmitter.

Lefty