CCST Calibration & Testing of Control Instruments

Question 1

What is the standard live zero signal range for a 4-20mA transmitter used in industrial process control?

Accepted Answer

4-20 mA

Answer

0-10 mA

Answer

0-20 mA

Answer

1-5 VDC

Question 2

What does 'zero suppression' mean when calibrating a differential pressure transmitter for level measurement?

Accepted Answer

Setting the zero point below the actual process zero to account for a static head offset

Answer

Removing the zero adjustment screw

Answer

Disabling the zero trim function in the transmitter

Answer

Calibrating the transmitter output to read zero at atmospheric pressure

Question 3

During a 5-point calibration of a pressure transmitter, at what percentages of span should calibration points typically be checked?

Accepted Answer

0%, 25%, 50%, 75%, 100%

Answer

0%, 20%, 40%, 60%, 100%

Answer

10%, 30%, 50%, 70%, 90%

Answer

5%, 25%, 50%, 75%, 95%

Question 4

What is 'as-found' data in the context of instrument calibration records?

Accepted Answer

The calibration data recorded before any adjustments are made during a calibration event

Answer

The calibration data recorded after adjustments are made

Answer

The manufacturer's factory calibration certificate data

Answer

The data recorded during the initial instrument installation

Question 5

A loop calibrator is used primarily to:

Accepted Answer

Source and measure 4-20mA signals to test and calibrate transmitters and I/P converters

Answer

Measure insulation resistance of signal cables

Answer

Generate 120VAC power for loop-powered devices

Answer

Measure the resistance of RTD sensors in the field

Question 6

When performing span adjustment on a transmitter, what are you changing?

Accepted Answer

The relationship between the input signal range and the output signal range (gain)

Answer

The minimum output signal at 0% of process input

Answer

The location of the transmitter's mounting bracket

Answer

The process variable engineering unit displayed on the HMI

Question 7

What is the primary purpose of performing a 'leak test' before calibrating a pressure or differential pressure transmitter?

Accepted Answer

To ensure there are no leaks in the calibration tubing or manifold that would cause incorrect applied pressure readings

Answer

To verify the transmitter's output signal is stable

Answer

To check that the transmitter housing seal meets IP65 requirements

Answer

To verify the process isolation valves are fully open