Posts Tagged analog output
Why has 4-20 mA gained so much acceptance and survived so long?
Posted by danstips in 4-20mA, Control, Process terminology, Standards on June 25, 2014
Last month, I presented a webinar for our customers. At the end of Control 101, when we opened the session up for questions, a customer asked about making the choice between 4-20 mA and digital signal outputs. It got me thinking about this list I put together a while back — one that I pull out whenever customers ask me “Is 4-20 mA still valid?”
The answer: Yes, it is. And here are the 18 reasons I came up with… so far. Read the rest of this entry »
LUT400 universal 4-20mA analog output gets rid of the ground loop
Posted by danweise in 4-20mA, HART, Installation, Level, Level Transmitters, Ultrasonic on August 16, 2013
The Problem
Before I talk about the value of a universal 4-20mA analog output on a level controller, let me explain why anyone would care. It’s all about ground loops.
Since the early days of electronic instrumentation, way back when, even before cell phones or PCs, instrument people struggled with ground loops that create an offset error, drive the signal off scale, or burn up an analog circuit.
Lesman Tech Tips 