Instrumentation
Instrumentation is the process
of measuring, calibrating, and controlling the physical variable such as pressure, flow,
temperature etc using a instrument.
Calibration
Calibration is the process of
checking the accuracy and correctness of an instrument by comparing it with a
standard instrument.
Accuracy
The degree of closeness to the true
value.
Precession
Pressure of repeatability of
measurement that is successive reading do not differ.
Error
The deviation of the true value from
the desire value.
Transducers
Transducer is defined as a device
that receives energy from one system and transmits it to another often in a
different form. Basically there are two types of transducers:
1.
Electrical
Transducers
2.
Mechanical
Transducers
An electrical transducer gives a
sensing device by which the physical, mechanical, optical quantity to be
measured, is transformed directly by a suitable mechanism into an electrical signal.
Electrical transducers can be
classified into two ways:
1.
Active
Transducers
2.
Passive
Transducers
Active Transducers
Active transducers generate an
electrical signal directly in response to the physical parameter and does not
require external power source for its operation. Active transducers are self
generating devices which operate under energy conversion principle and generate
an equivalent output signal.
Passive Transducers
Passive transducers operate under
energy controlling principle which makes it necessary to use an external
electrical source with them. They depend up on the change in an electrical
parameter (R, L, C).
E.g. Strain Gauge,
Thermistors
Selecting a
Transducers
Following should be considered while
selecting a transducer:
1.
Operating
range
2.
Sensitivity
3.
Environmental
compatibility
4.
Accuracy
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