How o measure 4-20 mA Current

That's basically how you do it. You can check various manufacturers reference designs, for example:

Analog Devices:

http://www.analog.com/en/design-center/reference-designs/hardware-reference-design/circuits-from-the-lab/cn0336.html#rd-overview

http://www.analog.com/en/design-center/evaluation-hardware-and-software/cu_eb_plc_demo_system.html

Texas Instruments:

Single Supply Analog Input Module Reference Design with 16-Bit, 8-Channel ADC for PLC - TIPD166 - TI Tool Folder

Analog Input Module for Industrial Outputs and Temperature Sensors Reference Design - TIPD164 - TI Tool Folder

Maxim:

https://www.maximintegrated.com/en/products/interface/current-loop-products-4-20ma.html

Thanks..

Is the situation: (a) Measuring DC Current (at Currents mentioned) AS you would using a (temporary) Test Instrument? OR (b) Circuitry that you would build that attaches to the circuitry that you want to monitor? IF (b) then the previously post Comments will do.

However if the situation is (a) then consider a "Portapow Premium USB+DC Power Monitor (portapow.co.uk). I have one and it works great. Remember this is DC. The documentation is lousy, but I drew-up several diagrams that explains the various connections. Will try to post them here BUT I haven't

gotten a Win10 Driver for the Scanner Portion of my Samsung SCX-4016scx MFP. WRT that I am attempting a "virtual" WinXP  w/i my Win10 PC. But that is Tangential to this discussion.

USCDADNYC (NY NY USA)

4-20mA is a nice standard for instrumentation measurement and is used in industry extensively. the nice thing about it is it has automatic fault detections as zero = 4mA, any less than 4 means an error, more than 20 also an error. being a current loop also means impervious to alot of noise sources and also lead length can be significant subject to the ability of the source to provide enough volts. It can even be measured by many series devices... anyway I digress (I spent many years in the Gas industry using 4-20mA transducers for pressure, flow and temperature.

Your current approach has been the mainstay for what seems forever. Use a resistor to measure the current (IE, convert the current to a voltage), typically a 200Ohm or 250Ohm is used to then provide a 5V FSD,but of course if your measurement device is only able to handle a lower voltage, reduce the sense resistor appropriately.

I am not aware of any current input ADC, those that claim to support 4-20mA are basically providing the current sense resistor themselves so you're no better off except for perhaps a lower BOM or board footprint.

Thanks Peter..

You can use the 4-20mA R click from MikroElektronika which combines the current measurement circuits and also provides 16V supply for the loop. Best way is to use it on an Arduino Uno click shield.

4-20mA R Click - mikroBUS sized board which serves as a receiver in a 4-20mA current loop standard

Arduino Uno click shield - mikroBUS host sockets extension for Arduino Uno compatible boards

You can find here some tutorials on using the 4-20mA T (transmitter) and  4-20mA R (receiver) boards:

https://microcontroller-projects.com/4-20ma-arduino-tutorial-hardware/

https://microcontroller-projects.com/4-20ma-current-loop-arduino-transmitter/

https://microcontroller-projects.com/4-20ma-current-loop-arduino-receiver/

I wrote this article for reading 4-20mA using Arduino. I am using ADS1115 and INA196 to read the current and convert into digital values.

feel free to check out.

https://ncd.io/how-to-read-4-20ma-current-loop-sensors/

i was looking for something lik this to and i found this on tindie
https://www.tindie.com/products/Circuitar/adc-4-20-nanoshield-ads1115-for-4-20ma-sensors/

A couple of others that might work:

ACS712

INA219