## Converting voltage to current

Forum for discussing PicoLog
tian
Newbie
Posts: 0
Joined: Thu Jun 20, 2024 10:02 am

### Converting voltage to current

Hi,

I am new to using PicoLog data logger.

I wish to measure the current of a 4-20mA device sensor using Picolog 1216.

To my understanding, the original values read on PicoLog would be instantaneous voltage that is output from the sensor.

My question is how would I convert that instantaneous voltage to current?

AndrewA
PICO STAFF
Posts: 420
Joined: Tue Oct 21, 2014 3:07 pm

### Re: Converting voltage to current

No we don't have a special 4-20mA probe.

For 4-20mA you would need to add a external resistor across the input to the channel.
For example at 20mA = (2.5V / 20mA = 125ohm) As the input range of the logger is 2.5 volts.
So you round this down to the nearest E series of resistor values, to give a voltage less than 2.5V.
So for example for E96 (1%) value this would be "124" -> 124 ohms
And would give-
20mA x 124 = 2.48V
This can be soldered on to the 1000 series small terminal board, see the guide for resistor placements-