Lesson 3 - Principles of Process Control SAQ
Completion requirements
Done: View
To do: Go through the activity to the end
This lesson allows you to test yourself on the material covered in the Principles of Process Control lesson and determine the level to which you have met the learning outcomes.
Suggested Response - Q1
* A standard analogue signal reads 4-20 mA. What does this indicate? Why do we not use 0-20mA?
Response:
4-20 mA is the range across which analogue signals are transferred. This will correspond to the range of the measured variable. 4 mA represents the lowest value and 20 mA represents the highest value in the range.
If no signal comes through, the value will read 0 mA. In such an instance, this would indicate that the instrument is faulty or that communication is bad.