Homework #1
Due date: Tuesday January 21, 2025 (01/21/2025)
(100 points)
Question 1: Define and elucidate the main elements of a measurement system.
Main elements of a measurement system:
-​ Input- substance that the user hopes to measure (not directly part of the measurement
system itself)
-​ Sensor- it senses the input signal and gives an output signal through a function of the
measurand
-​ Converter- converts the output signal of the sensor to a more convenient, readable
signal.
-​ Signal Conditioning Unit- used to improve the quality of the output signal by
increasing/decreasing the signal (amplifier) or removing
portions of the signal (like noise) through filtering.
-​ Output Element- indicates and/or records the measured value. If the user simply reads
the output and perhaps copies it to paper, the final device is an indicator. If the output
value is saved automatically in some way, the final device is a recorder
Question 2: Explain the two main functions of a transducer.
When the sensing and converting is done in the same step, the element is called the
transducer:
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Sensor: reads the input and triggers an output signal by the function mechanism of the
measurand
Converter: converts the output signal of the sensor into a more convenient and readable
signal so the user can understand it for themselves apply it to their needs
Question 3: Explain the three functions of a transmitter.
The three elements of the transmitter are the Sensor, Converter, and the Signal Conditioning
Unit. The functions of them are as follows:
-​ Sensor: senses/ reads the input
-​ Converter: converts the output signal of the sensor to a convenient readable signal
-​ Signal Conditioning Unit: improves the quality of output signal through amplification or
filtering
Question 4: By explaining the operating principle, identify the various elements of the
following measurement systems:
a. Mercury-in-glass thermometer
-​ Input- substance to be measured
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-​
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Sensor- Mercury in the bulb
Converter- Mercury in the bulb
Signal Conditioning Unit- capillary tube
Output Element- Scale engraved on the stem
Output- Temperature reading in desired units
b. Atomic force microscopy (AFM)
-​ Sensor: light sensor
-​ Converter: laser and the photodiode detector
-​ Signal Conditioning unit: The electrical signal from the photodiode processed by the
controller
-​ Output element: The output image of the AFM processed on the computer
c. Automobile speedometer
-​ Sensor: the rotational sensing magnet on the drive shaft, which pulse of electrical current
to the speedometer
-​ Converter: The speedometer's internal computer interprets the pulses and converts them
into a speed reading
-​ Signal Conditioning unit: internal electronic circuitry (eliminating noise, increase the
signal strength, a comparator circuit to convert the pulses into a clean square wave
signal