This is the first of several articles on the calibration and maintenance of so-called smart transmitters.
What, exactly is it that makes a transmitter smart? (Actually, this term can apply to a lot of instrumentation beyond just transmitters).
I think there are a few important qualifying characteristics.
- High accuracy
- High reliability
- Use of digital technology
- Remote communications availability
Points 1 and 2 are largely the result of careful design and the use of item 3, digital technology. I like to say that there are 5 basic components of a smart transmitter.
- Analog to digital signal processing. This is by far the most important aspect of the design when it comes down to the overall performance of the device. Converting that real world analog value, whether it be pressure, temperature, etc. to a digital value has to be done right.
- I/O (remote communications)
- RAM and/or ROM
- Digital to analog signal generation.
Here’s a pictorial representation:
Look for more in our next post.