4-20mA current loop measurement

Kevin72

Part Number: INA219

Hi team,

Can the INA219 be used to measure the current in a 4-20mA current loop, as described here: https://www.dataq.com/blog/data-acquisition/4-20-ma-current-loop-measurements/ under the example of "2-wire Sensors (High-side Shunt)"?

The circuit would look like this:

One concern is that the DC source does not share a common GND with the INA219 and controller. Note there is no need to measure the bus voltage in this application, only the shunt voltage (current flow).

Would the INA219 produce an accurate measurement in this configuration? If it is not suitable, can you recommend a part and/or configuration for measuring current in a 4-20mA current loop?

Thank you!

over 5 years ago

0 Kevin72 over 5 years ago

Prodigy 120 points

Sorry, I think this belongs in the Amplifiers forum, not the Sensors forum - is there a way to move it there?

0 Ian Williams over 5 years ago in reply to Kevin72

TI__Mastermind 27715 points

Hi Kevin,

No problem, I moved this to the Amplifiers forum.

Using the INA219 in this way is fine. Just make sure that the loop supply voltage (in your case 24V) relative to the GND of the INA219 stays within its input voltage limits, which is 26V.

You will still get accurate shunt voltage measurements if your bus voltage is invalid. However, the bus voltage and power measurements reported by the INA219 will not be correct.

Best regards,

Ian Williams
Applications Manager
Current Sensing

0 Kevin72 over 5 years ago in reply to Ian Williams

Prodigy 120 points

Thank you for the confirmation and very quick response! I will move ahead with this design and testing.