Instrumentation. Test 5 – Online Maritime Tests

What is an A/D and a D/A converter?

An amplifier for direct current.
A converter that converts alternating current into direct current and vice versa.
A converter stabilising the voltage.
A converter that converts an analogue signal to a digital signal and vice versa.

Two reference points for pressure exist, absolute zero and atmospheric pressure. What do you call pressures measured relative to absolute zero?

Absolute pressure
Vacuum pressure
Pressure drop
Gauge pressure

Which component does this graphical symbol illustrate?

PH analyzer
Pressure indicator, installed locally
Pressure relief valve, self-contained
Pressure indicator, installed on panel/console

This circuit symbol is an amplifier system and its frequency response diagram. Which control function is the system performing?

Proportional + integral + derivate (PID)
Proportional + derivate (PD)
Proportional + integral (PI)
Integral (I)

When calibrating an pressure transducer we have to adjust both SPAN and ZERO. Please indicate in which order these adjustments should be done.

First Span adjustment and then Zero adjustment. After that Span setting should be checked gain.
The order of adjustment is of no importance.
First Span adjustment and then Zero adjustment. After that Span setting should be checked again.
First Zero adjustment and the Span adjustment. Then Zero should be rechecked.

U-tube manometers are often used to measure differential pressure. Which of the listed pressures is U-tube manometers mostly used for?

Absolute zero pressure
Cargo pressure
Low differential pressures
High differential pressures

Two reference points for pressure exist, absolute zero and atmospheric pressure. What do you call pressures measured relative to atmospheric pressure?

Atmospheric pressure
Absolute pressure
Gauge pressure
Pressure drop

Liquid flow through pipe lines is often measured by means of differential pressure across a restriction (orifice) in the pipe as illustrated by this figure. Which of the listed formulas will you utilize for calculating the volumetric flow F?

Formula 4
Formula 1
Formula 2
Formula 3

Review Answers