We've had lots and lots of application questions since Dataforth introduced its new family of loop isolators last year! As you know, the 0-20mA and 4-20mA loops have been used for a very, very long time. Yet, it seems we don't work with them often enough to get details committed to memory. Or we have had problems with current loops in the past and we just wish to forget the experiences! Here's some solid information to keep at hand for your next current loop project.4-20mA Loop Isolator Application Note AN104
Dataforth's loop isolators simplify your applications. If you need to add a local digital panel meter or a data logger or even a new data acquisition system into an existing loop, Dataforth has an inexpensive passive isolator to do the job. Our devices (DSCL products) take a little power from the loop (<2 volts drop added to you loop device) to power themselves and to provide true galvanic isolation from the existing system... no ground loops or other electrical interaction between old and new systems! DSCL20, 21 and 22 models are passive two-wire isolators that are ideal for these types of applications.