Part 1 General Instrumentation

Question 1

Gross Error

Answer 1

Mistakes in reading or using instruments or calculations(mistakes in general) e.g error due to parallex, zero settings and wrong calibration

Question 2

Systematic Error

Answer 2

Remain constant, repeated based on a definite law while measuring a quantity. Can be; instrumental(bad calibration), environmental(humidity, temp) and observational (e.g parallax error) {IEO}

Question 3

Random error

Answer 3

Variable magnitude, do not follow any law, measured same quantity give diff. result. The mean value is considered to be the probable or likely value of the quantity.

Question 4

List instruments performance xteristics? Hint (PARRELSD)

Answer 4

1.Accuracy; closeness to true value
2.precision; measure of repeatability
3. Resolution; Smallest change in the input (quantity) thet will produce a change in the output ( instrument reading)
4. Sensitivity; measure of response to change in input to produce change in output.
5. Linearity; conformity to linear calibration curve, o.p proportional to i.p
6. Range;
7; Error; Diff. Between measured val and True val.
8. Deadspace; range at which instruments give no reading. {APRSLRED}

Question 5

Classes of Errors includes? Hint GSR

Answer 5

1. Gross Error
2. Systematic Error
3. Random Error.

Question 6

General instrumentation 1.{vmc}
2. Instruments are devices used to? {mcv}
3. Instrumentation {s-mti-vp}
4. Measurement {qc b/w q um}

Answer 6

1. In an industry set up, there are basic VARIABLES to be MEASURED and CONTROLLED so as to acheive a desired goal.
2. Instruments are devices used to measure and control these variables.
3. Instrumentation defined as SYSTEMATIC arrangements of instruments for MEASURING TRANSMITTING and INDICATING the condition of variable in a particular process.
4. Measurement; QUANTITATIVE COMPARISM B/W a given quantity and an ADAPTED UNIT OF MEASUREMENT.

Question 7

General instrumentation

Answer 7

1.{vmc}
2. Instruments are devices used to? {mcv}
3. Instrumentation {s-mti-vp}
4. Measurement {qc b/w q um}

Question 8

Instrumentation system diagram

Answer 8

Input= PTSO output(indicators, recorder, processor, controller) irpc

Question 9

What is measurement error and what are the seven classes of measurement error?

Answer 9

The deviation of measured value from the true value of quantity being measured is know as measurement error.
Classes include; 0.1, 0.2, 0.5, 1.0, 1.5, 2.5 and 4

Question 10

What is absolute Error?

Answer 10

Absolute Error is difference between instrument reading to true value (I.R to T.v)
δₐ=E₀=Aₘ-A
E₀=Absolute error
Am=measured value
A= Actual value

Question 11

What is limiting Error?

Answer 11

This is the laid down deviation from specified values incorporated by the manufacturer of a measuring instrument e.g 5±2% which means 5±0.1.
(Mathematical (x%100) * value) this is how we got 0.1

Question 12

Example 1 and 2 formulars

Answer 12

Question 13

Example 3 and 4 fomulars

Answer 13

Question 14

What are Dynamic Chraractersits? (DFSRM)

Answer 14

Dynamic Error; diff of t.v the quantity changing with time. Phase diff. between input and output.
Fidelity; ability to produce same output as input
Speed of response; speed of which an instrument respond to the variation of input quantity.
Response time: time to settle down to its final steady state position after applying an input.
Measuring Lag: delay in response to input

Question 15

Zero order instrument

Answer 15

1. They have no time storing capacity, the o.p is proportional to the I.p no matter how the input varies.

Question 16

Key words first part

Answer 16

Measured, controll, variable, quantity and quantitative