Scale: 1. Zero Error: The difference in value between the theoretical and practical calculation in the curve is the zero error. 2.Sensitivity error: these error occurs when the output deviates from correct value by content value.Dynamic: Occur only when input quantity is varying with time.Error due to noise and drift: Both vary with time, in case of noise- consist of random amplitude and random frequency but drift: is slow change with time.Both are independent of input signal.
Present by: Kausik Das.(0215)
Student of The assam Kaziranga university.
Classification of Transducers
Advantages & Disadvantages
Temperature and Heat
Advantages and disadvantages
• Transducers is a device which convert mechanical force
into electrical energy. We can also define transducers as
device which transform energy from one form to
Example Photo conductor which converts light intensity into a change of
Thermocouple which converts heat energy into electrical energy.
Transducers can be classified Primary and secondary
Active and Passive
Analog and Digital
Classification of transducers
Primary Transducer: The Mechanical device which converts physical
Secondary Transducer: The Electrical device which converts this
mechanical signal to the electrical signal.
Analog Transducer: These Transducers convert input quantity to an analog
output which is continuous function of time. Ex-Thermocouple or
Thermistor which gives analog output.
Digital Transducers- These converts the input quantity into an electrical
output which is in the form of pulses.
Passive Transducers: These transducers which require an auxiliary power
source to produce their output. Hence they are also known as externally
power transducers. Ex-Resistive, Capacitive, Inductive.
Active Transducers: These transducers which do not require an auxiliary
power source to produce their output. Ex- Thermocouple, photo voltaic
Inverse Transducers: These transducers converts an electrical quantity into
a non-electrical quantity. Ex-Piezo electric crystal.
• Antenna – converts propagating electromagnetic waves
to and from conducted electrical signals.
• Loudspeaker, earphone – converts electrical signals into
sound (amplified signal → magnetic field → motion → air
• Hydrophone – converts changes in water pressure into
an electrical signal.
• Microphone – converts sound into an electrical signal
(air pressure → motion of conductor/coil → magnetic
field → electrical signal)
Low Current consumption.
Operates in extremely cold temperature.
Power requirement is very low for controlling the
electrical or electronic system.
Advantages & Disadvantages
The mass inertia effect are minimized.
Effect of friction are minimized.
Electrical and electronic system is easily controlled with a
very small power level.
used, transmitted, processed for the purpose of
Advantages of Electrical
• Scale Error
•Error due to Noise and Drift
Errors in transducers
• A Temperature is a numerical measure of hot or cold. Its
measurement is by detection of heat radiation or particle
velocity or kinetic energy, or by the bulk behavior of
a thermometric material.
Heat is energy that is
transferred from one
body to another as the
result of a difference in
a measure of hotness or
coldness expressed in
terms of any of several
arbitrary scales like
Celsius and Fahrenheit.
Kelvin, Celsius or
Heat is a measure of how
many atoms there are in
a substance multiplied by
how much energy each
Temperature is related to
how fast the atoms
within a substance are
Ability to do work:
Heat has the ability to do Temperature can only be
used to measure the
degree of heat.
Temperature Vs Heat
Transducers for measuring
A pyrometer is a type of thermometer used to
measure high temperatures. It is used for measuring
temperature without any physical contact. Its is used for
measuring body temperature by measuring its
• Its principle depends upon the relationship between
temperature of a hot body and electromagnetic
radiation emitted by the body. When a body is heated it
emits thermal energy known as heat radiation. It is a
technique for determining a body temperature by
measuring its electromagnetic radiation.
Principle of Pyrometer
• It is used for high temperature measurement. At high
temperature other transducers such as thermometer may
melt due to direct physical contact but pyrometer can be
used for high temperature measurement without any
Pyrometer Vs other
Types of pyrometer
• It can measure very high temperatures as no contact
• They have high output and moderate cost.
• They possess fast response speed.
• It has a good accuracy.
• It is light in weight.
Advantages of Pyrometer
• It requires direct line of sight to the object (or furnace) which
the temperature is to be measured
• It is subjected to emissivity error
• The scale is non-linear
• It is expensive
Disadvantages of Pyrometer
• They can measure temperature above the range of
• They can be use in the environment where the use of
thermocouple is limited.
• They are used for the target which would be damaged any
contact with primary elements like thermocouples.
• They are used for measurement of Average temperature
of large surface area.
Applications of Pyrometer
If you have any doubt regarding this slide just inform me.
I love to solve it…….thank you.