1. Basic Concepts: Definitions Readability (R): indicates the closeness with which the scale of the instrument may be read.Readability (R): indicates the closeness with which the scale of the instrument may be read. Readability < Readability Readability < Readability Least count (LC): indicates the smallest difference between two indications that can be detected on the instrument scale.Least count (LC): indicates the smallest difference between two indications that can be detected on the instrument scale. 37º37.5º 37.737.8 LC = 0.1

2. Basic Concepts: Definitions - Both the “readability” and the “least count” depend on: scale length, spacing graduation, and size of pointer. -These two definitions have no meaning with Digital instruments. Sensitivity (S): the ratio of the linear movement of the pointer on an analog instrument to the change in the measured variable causing this motion.Sensitivity (S): the ratio of the linear movement of the pointer on an analog instrument to the change in the measured variable causing this motion. - Higher S means better instrument.

3. Definitions-continue Hysteresis Error (HE): related to the difference in readings depending whether the value of the measured quantity is approached from above or below.Hysteresis Error (HE): related to the difference in readings depending whether the value of the measured quantity is approached from above or below. - H.E. may the result of: friction, magnetic field, elastic deformation, thermal effects,…

4. Definitions-continue Accuracy (A): “the closeness of the agreement between the result of a measurement and a true value of the measured.” It indicates the deviation of a reading from a known point.Accuracy (A): “the closeness of the agreement between the result of a measurement and a true value of the measured.” It indicates the deviation of a reading from a known point. -Usually expressed as a percentage of a full scale. -Precision (P): indicates the ability of an instrument to reproduce a certain reading with a given accuracy.

5. Definitions-continue Error: the deviation of an instrument reading from a known value.Error: the deviation of an instrument reading from a known value. Uncertainty: “a parameter, associated with the result of a measurement, that characterizes the dispersion of values that could reasonably be attributed to the measured.” Or: the range of instrument readings where the known value is not available.Uncertainty: “a parameter, associated with the result of a measurement, that characterizes the dispersion of values that could reasonably be attributed to the measured.” Or: the range of instrument readings where the known value is not available. Calibration: a comparison of a particular instrument with another higher accuracy instrument, or with a known input source.Calibration: a comparison of a particular instrument with another higher accuracy instrument, or with a known input source.

6. Dimensions and units Fundamental dimensions:Fundamental dimensions: -L = length -M = mass -F = Force -  = time -T = temperature All other physical quantities used may be expressed in terms of these fundamental dimensions.All other physical quantities used may be expressed in terms of these fundamental dimensions.

7. Dimensions and units QuantityUnitSymbol Basic units Lengthmeterm Masskilogramkg Timeseconds Electric currentampereA TemperatureKelvinK Luminous intensitycandelacd Supplemental units Plane angleradianrad Solid anglesteradiansr See table 2.6 for derived SI units Basic and supplement SI units

8. The generalized measurement system -Most measurement systems may be divided into three parts: 1.A detector-transducer stage: detects the physical variable and perform either a mechanical or electrical transformation to convert the signal into a more usable form. 2.Intermediate stage: modifies the direct signal by amplification, filtering, or other means so that desirable output is available. 3.Final or terminating stage: indicate, record, or control the measured variable.

9. The generalized measurement system; Burdon-tube pressure gage Detector- transducer stage Indicator stage Modifying stage

10. System Response …

11. Experimental Planning 1.- Establish the need for the experiment. - Establish the budgetary, manpower, time,… - Establish the budgetary, manpower, time,… 2.Plan your experiment: objectives, variables to be measured, the required accuracy, no. of measurements, possible error sources, … 3.Select instrumentations 4.Conduct a primary experiment and analyze the data 5.Modify in accordance with step 4 6.Conduct the bulk of experimental data and the results 7.Organize, discuss, and state the results