Transducers and Sensors
Introduction Define a transducer and sensor
The operation and applications of transducers
Research the following types of transducers. You may write your findings in tabular or
non-tabular form if you cover all points in the table.
Name of Transducer Is it Operational Principles Applications
passive or (How does it work?)
active?
passive These devices depend on the These devices are
Light Dependant light, when light falls on the LDR used where there is
Resistor then the resistance decreases and a need to sense the
increases in the dark. When a LDR presence and
is kept in the dark place, its
absence of light is
resistance is high and when the
necessary. These
LDR is kept in the light its
resistors are used as
resistance will decrease.
light sensors and the
applications of LDR
mainly include alarm
clocks, streetlights,
light intensity
meters, burglar
alarm circuits.
active A thermocouple is a device for Thermocouples are
Thermocouple measuring temperature. It used in applications
comprises two dissimilar that range from
home appliances to
metallic wires joined together
industrial processes,
to form a junction. When the
to electric power
junction is heated or cooled, a generation, to
small voltage is generated in furnace monitoring
the electrical circuit of the and control, to food
thermocouple which can be and beverage
measured, and this
corresponds to temperature.
passive The switching mechanism is Reed switches are
Reed switch comprised of two used in fluid level
ferromagnetic blades, sensors for brake
separated by only a few fluid reservoirs and
microns. When a magnet to monitor motor oil
, approaches these blades, the levels. They are also
two blades pull toward one used in speed
another. Once touching, the sensors for engine
blades close the normally open control and power
(NO) contacts, allowing steering. Automatic
electricity to flow. door locks, air bags,
parking brakes, seat,
door, and hood
proximity sensors
also utilize reed
switches.
passive A strain gauge is a sensor Strain gauges are
Strain gauge whose resistance varies with used to measure the
applied force; It converts force, torque applied by a
pressure, tension, weight, etc., motor, turbine, or
into a change in electrical engine to fans,
resistance which can then be generators, wheels,
measured. When external or propellers. This
forces are applied to a equipment is found
stationary object, stress and in power plants,
strain are the result. ships, refineries,
automobiles and
industry at large.
Power is obtained by
measuring the strain
and rotational speed
on a shaft.
active A piezoelectric crystal is placed Piezoelectric igniters
Piezoelectric device between two metal plates. ... are commonly used
Mechanical pressure is then for butane lighters,
applied to the material by the gas grills, gas stoves,
metal plates, which forces the blowtorches, and
electric charges within the improvised potato
crystal out of balance. Excess cannons. Electricity
negative and positive charges Generation — Some
appear on opposite sides of applications require
the crystal face. the harvesting of
energy from
2
BTEC Assignment Brief v2.0
BTEC Internal Assessment January 2020
, pressure changes,
vibrations, or
mechanical impulses.
passive A thermistor is a resistance Thermistors are
Thermistor thermometer, or a resistor used as
whose resistance is dependent temperature
on temperature. The term is a sensors. They can
combination of “thermal” and be found in every
“resistor”. ... When day appliances
such as fire alarms,
temperature increases, the
ovens and
resistance increases, and when
refrigerators. They
temperature decreases,
are also used in
resistance decreases. This type
digital
of thermistor is generally used thermometers and
as a fuse. in many automotive
applications to
measure
temperature.
Investigating Transducers
Calibrating a Thermocouple
Aim
The goal is to calibrate thermocouples, which is the procedure of calibrating an
instrument to produce an acceptable picture for a sample.
Hypothesis
I predict that as the temperature of the water decreases, so will the temperature of
the thermocouple.
Diagram
3
BTEC Assignment Brief v2.0
BTEC Internal Assessment January 2020
Introduction Define a transducer and sensor
The operation and applications of transducers
Research the following types of transducers. You may write your findings in tabular or
non-tabular form if you cover all points in the table.
Name of Transducer Is it Operational Principles Applications
passive or (How does it work?)
active?
passive These devices depend on the These devices are
Light Dependant light, when light falls on the LDR used where there is
Resistor then the resistance decreases and a need to sense the
increases in the dark. When a LDR presence and
is kept in the dark place, its
absence of light is
resistance is high and when the
necessary. These
LDR is kept in the light its
resistors are used as
resistance will decrease.
light sensors and the
applications of LDR
mainly include alarm
clocks, streetlights,
light intensity
meters, burglar
alarm circuits.
active A thermocouple is a device for Thermocouples are
Thermocouple measuring temperature. It used in applications
comprises two dissimilar that range from
home appliances to
metallic wires joined together
industrial processes,
to form a junction. When the
to electric power
junction is heated or cooled, a generation, to
small voltage is generated in furnace monitoring
the electrical circuit of the and control, to food
thermocouple which can be and beverage
measured, and this
corresponds to temperature.
passive The switching mechanism is Reed switches are
Reed switch comprised of two used in fluid level
ferromagnetic blades, sensors for brake
separated by only a few fluid reservoirs and
microns. When a magnet to monitor motor oil
, approaches these blades, the levels. They are also
two blades pull toward one used in speed
another. Once touching, the sensors for engine
blades close the normally open control and power
(NO) contacts, allowing steering. Automatic
electricity to flow. door locks, air bags,
parking brakes, seat,
door, and hood
proximity sensors
also utilize reed
switches.
passive A strain gauge is a sensor Strain gauges are
Strain gauge whose resistance varies with used to measure the
applied force; It converts force, torque applied by a
pressure, tension, weight, etc., motor, turbine, or
into a change in electrical engine to fans,
resistance which can then be generators, wheels,
measured. When external or propellers. This
forces are applied to a equipment is found
stationary object, stress and in power plants,
strain are the result. ships, refineries,
automobiles and
industry at large.
Power is obtained by
measuring the strain
and rotational speed
on a shaft.
active A piezoelectric crystal is placed Piezoelectric igniters
Piezoelectric device between two metal plates. ... are commonly used
Mechanical pressure is then for butane lighters,
applied to the material by the gas grills, gas stoves,
metal plates, which forces the blowtorches, and
electric charges within the improvised potato
crystal out of balance. Excess cannons. Electricity
negative and positive charges Generation — Some
appear on opposite sides of applications require
the crystal face. the harvesting of
energy from
2
BTEC Assignment Brief v2.0
BTEC Internal Assessment January 2020
, pressure changes,
vibrations, or
mechanical impulses.
passive A thermistor is a resistance Thermistors are
Thermistor thermometer, or a resistor used as
whose resistance is dependent temperature
on temperature. The term is a sensors. They can
combination of “thermal” and be found in every
“resistor”. ... When day appliances
such as fire alarms,
temperature increases, the
ovens and
resistance increases, and when
refrigerators. They
temperature decreases,
are also used in
resistance decreases. This type
digital
of thermistor is generally used thermometers and
as a fuse. in many automotive
applications to
measure
temperature.
Investigating Transducers
Calibrating a Thermocouple
Aim
The goal is to calibrate thermocouples, which is the procedure of calibrating an
instrument to produce an acceptable picture for a sample.
Hypothesis
I predict that as the temperature of the water decreases, so will the temperature of
the thermocouple.
Diagram
3
BTEC Assignment Brief v2.0
BTEC Internal Assessment January 2020
