ELECTRICAL & ELECTRONICS MEASURING INSTRUMENTS

Slides:

Advertisements

Similar presentations

12 TH STANDARD PHYSICS CURRENT ELECTRICITY Prepared by: R.RAJENDRAN, M.A., M.Sc., M.Ed., N.INGARAN, M.Sc., M.Phil.,M.Ed.,

Advertisements

TEMPERATURE measurements

PH0101 UNIT 4 LECTURE 9 GAS THERMOMETER

Nkp/eee skcet Electrical And Electronics Instruments N Krishna Prakash.

Prepared By: Shakil Raiman.  Resistors is a device which can reduce the current.  The resistance of a wire is calculated by R=V/I (which comes from.

Thermocouples Most frequently used method to measure temperatures with an electrical output signal.

Thermo Electric Effects & Temperature Measurement

Met 163: Lecture 4 Chapter 4 Thermometry.

Mechanical Measurement and Instrumentation MECN 4600

Met 163: Lecture 4 Chapter 4 Thermometry. Thermoelectric Sensors The junction of two dissimilar metals forms a thermocouple. When the two junctions are.

Chapter 26 DC Circuits Chapter 26 Opener. These MP3 players contain circuits that are dc, at least in part. (The audio signal is ac.) The circuit diagram.

Thermocouples Most frequently used method to measure temperatures with an electrical output signal.

Thermocouples Most frequently used method to measure temperatures with an electrical output signal.

Module 3 Eng. Asma Abu Baker. Introduction One of the most important uses of instruments or measuring devices is in the field of process control. If you.

Temperature Sensors.

Temperature 1.  Temperature is defined as the degree of hotness or coldness of a body measured on a definite scale  Temperature is the driving force.

Resistance. This is a measure of a materials opposition to the flow of current through it. Unit: Ohms ( Ω )

©1997,2001 by M. Kostic Ch.8: Temperature Measurement Temperature:Temperature: measure of hotness or coldness indicating the direction in which heat (energy)

Electric Current. Answer Me!!!  Why are electric wires made from metal?

Essentials of Electronics

T OPIC 4 – T HE ENERGY C ONNECTION Science 9 - Electricity.

Junctions and Semiconductors Theories and practical devices.

Engineering Mechanical Laboratory Term 1/2009 Lab 9 (b): Thermocouple Lab 9 (a): Viscosity Nopdanai Ajavakom.

Introduction to Temperature Sensors

PSAA Curriculum Unit Physical Science Systems. Problem Area Energy and Power Systems.

EXAMPLE 27.1: A copper wire carries a current of 10 A. It has a cross- sectional area of 0.05 cm 2. Estimate the drift velocity of the electrons.

Direct Current Circuits A current is maintained in a closed circuit by an emf (electromotive force) Battery. An emf forces electrons to move against the.

2 But what makes the electrons flow? Any electrical circuit requires three things 1.A source 2.A load 3.A means of transmission A definition of a current.

Thermocouples (continued) Introduction to Temperature Sensors ISAT 300 Instrumentation and Measurement 02/21/2000.

The Measurement of Temperature

The RMS voltmeter Thermocouple: convert heat into output dc voltage.

Electrical And Electronics Instruments

Thermocouples Thomas Johann Seebeck, 1821, discovered that a circuit of two different metals with junctions at different temperatures produced an electromotive.

1© Manhattan Press (H.K.) Ltd Potentiometer Comparing resistances Measuring the e.m.f. of a cell Measuring the internal resistance of a cell.

CURRENT, RESISTANCE, AND ELECTROMOTIVE FORCE Chapter 4.

TITEL OF PRESENTATION :- ANALOG MEASURING INSTRUMENTS PREPARATION NAME ENROLLMENT NO.:  MR.SAVALIYA SURESH T  MR. SAVALIYA VISHAL H

Electrical Measurement & Measuring Instrument

Copyright © 2005 Heathkit Company, Inc. All Rights Reserved Automating and Integrating Residential Systems Presentation 10 – Air Conditioning Simulation.

Chapter 26 DC Circuits. I The wires used in homes to carry electricity have very low resistance. However, if the current is high enough, the power will.

Department :- Electrical Engineering Subject :- Electrical Measurement & Measuring Instruments ( ) Group No:- 04.

Thermocouples Most frequently used method to measure temperatures with an electrical output signal.

RESISTIVE TEMPERATURE TRANSDUCERS

DC circuit theory.

Electric current.

Temperature sensors Temperature is the most often-measured environmental quantity. This might be expected since most physical, electronic, chemical, mechanical,

MECH 373 Instrumentation and Measurements

The Measurement of Temperature

Sigma Institute of Engineering

Vidhyadeep institute of management and technology Electrical : B

Thermocouples and rtd Prepared By: Ansari Najma A. ( )

TEMPERATURE SENSOR.

Electrical And Electronics Instruments

Different types of Electronics Instruments and principles

THERMAL, CHEMICAL AND THERMOELECTRIC EFFECT

Chapter 6 Overview.

Temperature and Thermometers

A Microscopic View of Electric Circuits

THERMAL, CHEMICAL AND THERMOELECTRIC EFFECT

Prepared by Dr. Mohamed Ahmed Awad

Electrical Engineering Technology EE306

DIRECT CURRENT CIRCUITS

Warm up set 7 Question Answer:

Electric Current.

Thermal Sensors Q = mcT, where Q is the amount of heat in J, T is temperature in K, m is the mass in kg, c is the specific heat capacity in J/(Kg.K), and.

Thermal Equilibrium Temperature Scale Practical Thermometers

Instruments & Electrical Measurements Lecture 3

Thermoelectric & Thermionic conversions

T- Norah Ali Al- moneef king Saud university

Presentation transcript:

2130903 ELECTRICAL & ELECTRONICS MEASURING INSTRUMENTS PREPARED BY:- 140010109047 Sabva Vipul

THERMOCOUPLE INSTRUMENT/ TRANSDUCER

Seeback Effect In these instruments use of seeback effect is made according to that if the junction of two wires of dissimilar metals ( such as iron and a copper-nickle alloy) is heated and the free or cold ends are connected to a millivoltmeter , an emf is caused.

Elements of Thermocouple Instrument 1. Heater element 2. Thermocouple 3. PMMC Instrument

Principle of Operation The thermoelectric e. m. f Principle of Operation The thermoelectric e.m.f. generated in a thermocouple is proportional to the difference of temperatures of hot and cold junctions. This relation is parabolic in nature and given by e = a(T1-T2) + b(T1-T2)2 Where a, b = Constants depending on metals. T1 — T2 Temperature difference of hot and cold junctions. Let  t = T1 — T2 = Difference in temperatures.

e= a t + b t2 ......(2) The equation (2) shows that thermo-electric e.m.f. (e) has a parabolic relationship with the temperature difference  t. The constant a is of the order of 40 to 50 μV per °C difference of temperature. The constant b is of the order of few tenths or hundredths of a microvolt per (°C)2. The heater element carries the current to be measured and heat produced is proportional to square of the r.m.s. value of the current. Thus the rise in temperature of hot junction is proportional to I2 R where I is the r.m.s. value of the current and R is the resistance of the heater element.

If the cold junction is maintained at ambient temperature then the rise in temperature of hot junction is equal to temperature rise of hot junction above the ambient temperature.  t = Rise in temperature And  t  I2 R i.e.  t = K1 I2 R …(3) Note: The equation (3) shows that thermocouple instruments show the square law response.

Practically the value of constant b is very small and can be neglected Practically the value of constant b is very small and can be neglected.  e=a t e = a K1 I2 R This e.m.f. drives the PMMC instrument to cause the deflection Ѳ proportional to e.m.f. e. Ѳ = Deflection of instrument  e. Ѳ = K2e=K2[a K1 I2 R] Ѳ = K3 I2 where K3 = K1 K2 a R = Constant