**Open Education Resource: Flipped Classroom Videos, Presentations and Assessment (Out of Class Activity)**

## College: Bannari Amman Institute of Technology

## RC_1073_Team_1

Team Members: Sajan P Philip, Shalini E, Subhasakthe S A

### OER Detailed Documentation -Click the Link

## Subject Name: 11L502 Measurement and Instrumentation

**Introduction to the Subject: **

This subjects deals with the methods for various measurements of physical quantities and electronic instruments that are built to perform this measurement. In Electronic Measurement, the quantity under measurement is converted to a useful form, such as a voltage, current or physical displacement by an input transducer or sensor. There are various techniques for detection and analysis of various quantities have been developed and implemented in the field of Instrumentation.

Suggested Reading:

Reference Text Book 1: Modern electronic instrumentation and measurement techniques, Albert D. *Helfrick*, William David *Cooper*. Prentice Hall.

Reference Text Book 2:Ernest, Doeblin, Dhanesh and N.Manik, Measurement Systems- Application and Design, Tata McGraw-Hill

Reference Text Book 3: A *Course* in Electrical and Electronic Measurements and Instrumentation , A.K.sawhney, Dhanpat Rai & Co.

Target Audience: 5th Semester ECE/EEE/EIE Students

### Unit 1: Bridge Measurement

## Lesson 1. Introduction to Bridge Measurement

**1. Introduction**

Precision measurement of component values have been made for many years using various forms of Bridges. The simplest form of bride is for the purpose of measurement of Resistance, called Wheatstone Bridge. There are variations of the Wheatstone bridge for measuring very high and very low resistances.

There is an entire group of bridges used for measuring Inductance, Capacitance, Admittance, Conductance and frequencies known as AC Bridges. Even though Modern sensors have overtook the place of Bridges, some specialized measurement such as Impedance at high frequencies are still measured using Bridge.

**2. Revised Blooms Taxonomy**

The 2 Dimensional Revised Blooms Taxonomy based General Objective and Specific Objectives for the lesson is give below.

**2. 1 General Objective of this Lesson:**

To learn about the construction of Wheatstone Bridge

**2.2 Specific Objectives of this Lesson**

- To identify the need for Bridge Measurement (Conceptual- Remembering)
- To explain the Construction of Wheatstone Bridge (Conceptual- Understanding)
- To analyze the Bridge Balance equation of Wheatstone Bridge (Procedural – Analysis)

**3. Out of the Class Video (Creative Commons)**

**4. Presentation for this Lesson (Creative Commons)- Click Below link**

**5. Reflection Quiz (Creative Commons) Scroll Down to View all the Questions**

## Lesson 2: Kelvin & Kelvin Double Bridge

**1. Introduction**

The Kelvin Bridge is a modification of the Wheatstone Bridge and provides greatly increased accuracy in the measurement of low value resistances generally below 1 Ohm. This is because the Kelvin Bridge consider the effect of Lead Resistance in the measurement of Unknown resistances.

Kelvin Double bridge is a modification of Kelvin Bridge. This is also used for low value Resistance Measurement. The term double is used because the circuit contains a second set of ratio arms. This eliminates the effect of Yoke/Lead Resistance in the the measurement.

**2. Revised Blooms Taxonomy**

The 2 Dimensional Revised Blooms Taxonomy based General Objective and Specific Objectives for the lesson is give below.

**2. 1 General Objective of this Lesson:**

To learn about the construction of Kelvin and Kelvin Double Bridges

**2.2 Specific Objectives of this Lesson:**

- To analyze the effect of Lead Resistance in Resistance measurement (Procedural -Analysis)
- To explain the Construction of Kevin Double Bridge (Conceptual – Understanding)
- To analyze the Bridge Balance equation of Kelvin Double Bridge (Procedural – Analysis)

**3. Out of the Class Video (Creative Commons)**

**4. Presentation for this Lesson (Creative Commons)- Click Below link**

**5. Reflection Quiz (Creative Commons)- Scroll Down to View all the Questions**

## Lesson 3: Maxwell’s Inductance Bridge

**1. Introduction**

The AC bridges are extension of DC Bridges with AC Power Supply and Passive components like Capacitor and Inductor. They are used to measure the unknown quantities like Inductance, Capacitance, frequency etc. In AC Bridges, the power source supplies an AC voltage to the bridge at a desired frequency. At higher frequencies, an Oscillator supplies the excitation voltage. The null detector can be a Head Phone or Amplifier with an output meter or a CRO.

Maxwell bridge is a modification of the basic AC bridge idea. Maxwell bridge measures an unknown inductance in terms of a known capacitance. One of the ratio arms has a resistance and a capacitance in parallel. The unknown arm contains a resistor and Inductor in series.

**2. Revised Blooms Taxonomy**

The 2 Dimensional Revised Blooms Taxonomy based General Objective and Specific Objectives for the lesson is give below.

**2. 1 General Objective of this Lesson:**

To learn about the basic idea of an AC bridge and the construction of Maxwell’s Inductance Bridge

**2.2 Specific Objectives of this Lesson:**

- To analyze the Balance condition for an AC Bridge (Conceptual -Analysis)
- To explain the Construction of Maxwell’s Inductance Bridge (Conceptual – Understanding)
- To analyze the Bridge Balance equation of Maxwell’s Inductance Bridge (Procedural – Analysis)

**3. Out of the Class Video (Creative Commons)**

**4. Presentation for this Lesson (Creative Commons)- Click Below links**

**5. Reflection Quiz (Creative Commons) Scroll Down to View all the Questions**

## Lesson 4: Schering Bridge

**1. Introduction**

Schering Bridge is another important bridge used extensively for the measurement of Capacitors. This is also an AC Bridge. The main advantage of using Schering Bridge is that it can be constructed easily. However, the bridge is frequency dependent. The standard arm contain only a Capacitor.

**2. Revised Blooms Taxonomy**

**2. 1 General Objective of this Lesson:**

To learn about the the construction and Balance equation of Maxwell’s Inductance Bridge

**2.2 Specific Objectives of this Lesson:**

- To explain the Construction of Schering Bridge (Conceptual – Understanding)
- To analyze the Bridge Balance equation of Schering Bridge for Capacitance Measurement (Procedural – Analysis)

**3. Out of the Class Video (Creative Commons)**

**4. Presentation for this Lesson (Creative Commons)- Click Below links**

**5. Reflection Quiz (Creative Commons)- Scroll Down to view all the Questions**

Schering Bridge Reflection Quiz

## Lesson 5: Anderson Bridge

**1. Introduction**

Anderson Bridge is another Bridge used for the measurement of Inductance in term of Capacitance. Here fixed capacitors can be used instead of the variable capacitors seen in the other type of Bridge circuits. The main advantage of Anderson bridge is that it is easy to balance and the Balance equation does not contain any frequency terms. Also there are some disadvantages like complicated circuit and connections, more number of Components and complex analysis involved.

Anderson bridge is also known as Modified Maxwell’s Bridge. This bridge is basically used for the precise measurement of inductance over a wide range of values.

**2. Revised Blooms Taxonomy**

**2. 1 General Objective of this Lesson:**

To learn about construction and balance equation of Anderson Bridge

**2.2 Specific Objectives of this Lesson:**

- To explain the Construction of Anderson Bridge (Conceptual – Understanding)
- To analyze the Bridge Balance equation of Anderson Bridge for Inductance measurement (Procedural – Analysis)

**3. Out of the Class Video (Creative Commons)**

**4. Presentation for this Lesson (Creative Commons)- Click Below link**

**5. Reflection Quiz (Creative Commons)- Click Below link**

## Lesson 6: Hay & Wein Bridge

**1. Introduction**

The Hay bridge differs from the Maxwell Bridge by having a Resistor R1 in series with the Standard Capacitor C1 instead of Parallel connection. Hay circuit is more convenient for measuring high Q coils. The main disadvantage of Hay Bridge is that the expressions for the unknown inductance and resistance both contain the angular velocity term. Hence the frequency of the excitation voltage source must be clearly known.

The Wein Bridge is another important Bridge circuit used for measuring frequency. It is also used as a harmonic distortion analyzer. It has lot of applications in High Frequency oscillations as frequency determining element. Because of the frequency sensitivity, the Wein bridge may be difficult to balance, unless the waveform of the applied voltage is purely sinusoidal.

**2. Revised Blooms Taxonomy**

**2. 1 General Objective of this Lesson:**

To learn about the construction and balance conditions of Hay Bride and Wein Bridge

**2.2 Specific Objectives of this Lesson:**

- To explain the Construction of Hay Bridge(Conceptual – Understanding)
- To analyze the Bridge Balance equation of Hay Bridge for Capacitance Measurement (Procedural – Analysis)
- To explain the Construction of Wein Bridge(Conceptual – Understanding)
- To analyze the Bridge Balance equation of Wein Bridge for Frequency Measurement (Procedural – Analysis)

**3. Out of the Class Video (Creative Commons)**

**4. Presentation for this Lesson (Creative Commons)- Click Below link**

**5. Reflection Quiz (Creative Commons)- Click Below link**

## 6. Formative Assessment Test for Unit 1

## 7. Feedback About the OER