Measurement And Instrumentation Question Paper

Measurement And Instrumentation

Course:Bachelor Of Science (Water Resources & Environmental Management) ()

Institution: Kenyatta University question papers

Exam Year:2009

KENYATTA UNIVERSITY
UNIVERSITY EXAMINATIONS 2009/2010
FIRST SEMESTER EXAMINATION FOR DEGREE OF BACHELOR OF SCIENCE

MANUFACTURING ENGINEERING, ENERGY ENGINEERING, AND
WATER AND ENVIRONMENTAL ENGINEERING

SET 313: MEASUREMENT AND INSTRUMENTATION
=================================================================
DATE: TUESDAY 22ND DECEMBER 2009 TIME: 2.00 P.M. – 4.00 P.M.

INSTRUCTIONS
Answer any THREE (3) questions.
All Questions carry equal 20 marks each
Use clear and neat diagrams

Q.1.
a) Represent the general structure of a measurement system in block

diagram form and give a brief description of each element and a relevant

example
of
it.
(5
marks)

b) i)
Distinguish between accuracy and precision in a measuring system.

ii)
Given the errors in the transducer and the other system elements are

7%, 8% and 5% respectively. Calculate both the maximum possible

system error and the probable error.

(5 marks)

c) i)
Name the three standard test inputs used in specifying the dynamic

performance of both measuring and control systems.
Page 1 of 4

ii)
Draw the step response of an underdamped system and indicate the

parameters used to specify the system response.

(5 marks)

d) A temperature measuring system incorporates a platinum resistance

thermometer, a wheatstone bridge, a voltage amplifier, and a pen recorder.

The individual sensitivities. are as follows:
transducer 0.35 ohms/ oc;

Wheatesone bridge 0.01 V/ohm; Pen recorder 0.1 cm/ V; Amplifier gain 100

V/V.
Determine :- i)
The overall system sensitivity

ii)
The temperature change corresponding to a recorder pen movement of

4 cm.

(5 marks)

Q.2
a) Distinguish between the following terms used in measurement systems:-

i)
‘Error’

ii)
Uncertainty
(2
marks)

b) Briefly discuss “ERRORS” under the following subheadings and giving at
least three examples of each based on the causes of these errors:-
i)
Systematic or cumulative errors;
ii)
Accidental or Random errors;
iii)
Miscellaneous type of Gross Errors.

(12 marks)

c) A voltmeter with an internal resistance of 200 k ? is connected across an

unknown resistance. It reads 250V and the milliameter (with very small

internal resistance) connected in series with the same resistance reads 10mA.

i) Determine:

1)
The apparent resistance,

2)
The Actual resistance and

3)
The loading error due to the loading effect of the voltmeter.

(4 marks)
Page 2 of 4

ii)
Find the loading error in this case if the same voltmeter and

milliameter is connected with another unknown resistance and the

reading is 100V and 2A respectively.
Q.3
a) In a typical general measurement system distinguish between:-

i)
Basic fundamental elements and,

(3 marks)

ii)
Auxiliary
elements
(2
marks)

b) List ten desirable characteristics that a transducer element should have when

selecting a transducer for a particular
application.
(5
marks)

c) The output of a transducer element is usually too small to operate an indicator

or recorder. Therefore, it is suitably processed and modified in the signed

conditioning element so as to obtain the output in the desired form.

List at least FIVE signal conditioning operations that can be carried out on the

transduced
information.
(5
marks)

d) The data presentation element gathers the output of the signal conditioning

element and presents the same to be read or seen by the experimenter.

i)
List THREE important characteristics it should have

ii)
Give TWO examples of data presentation elements
(5 marks)

Q.4
a) Explain, with the aid to a sketch and block diagram how bourdon tube

pressure gauge operated and identify the functional elemtns. Show how the

performance of this pressure measuring device can be improved using a linear

variable
different
transducer. LVDT

(7 marks)

b) Distinguish between analogue and Digital meters as you list advantages and

disadvantages
of
each.

Also, show, with the aid of sketch, how Analogue-to-digital conversion is

carried out.

(7 marks)

c) Briefly describe with the aid of sketches:-
i)
a digital computer system
Page 3 of 4
ii)
How a digital computer may be rised for the measurement and control
of a process involving several input signals e.g. temperature, pressure
etc, that are analogue in nature. (6
marks)

Q.5
With the aid of a sketch, give brief descriptions of any one device you could use

to measure the following, as you explain how they operate:-

a)
Flow
measurement
(4
marks)

b)
Temperature
measurement
(4
marks)

c)
pressure
measurement
(4
marks)

d)
dynamic
power
measurement
(4
marks)

e) Force or Torque or Mass or Strain measurement

(4 marks)

Page 4 of 4

📘 Access 10,000+ CBC Exams With Marking Schemes

Measurement And Instrumentation Question Paper

More Question Papers

Exams With Marking Schemes

End Term 3 Exams

Mid Term Exams

End Term 1 Exams

Opener Exams

Full Set Exams