Question 245General Subjects - 1st Asst/Chief
70% to passWhile calibrating an electronic 4-20 mA or 3-15 PSI pneumatic controller, what is the value of 'Live Zero'?
A'0' for input span and another value for output range.
B4 mA or 3 PSI for process output range.
C'0' for span and range.
D4 mA or 3 PSI.
AI Explanation
The correct answer is D) 4 mA or 3 PSI. The 'live zero' for a 4-20 mA or 3-15 PSI pneumatic controller refers to the minimum value of the output range, which is 4 mA or 3 PSI respectively. This is the value that represents the zero or bottom end of the measurement or control range for the device. The live zero is not zero, but rather the lower end of the specified output range, which allows for detection of faults or issues with the system. The other options are incorrect because A) refers to the input span, not the output range, C) is incorrect as the live zero is not zero, and B) is partially correct but does not fully capture the definition of live zero.
Related Questions
Q301:In accordance with the federal regulation in 33CFR Subchapter O, which discharge... Q39:The vacuum maintained in the salt water feed heater shell of a flash-type evapor... Q130:Before doing any work on a hydraulic system equipped with accumulators, you shou... Q191:A spur gear pump should be operated with the discharge valves _______________. Q185:While making a round in the lower engine room you discover a leak in the suction...
Ready to test your knowledge?
Take a General Subjects - 1st Asst/Chief Practice ExamOfficial Resources