IT's a little bit useful for engineering student

1. Measurements &
Instrumentation
Assignment-2
Submitted By:-
Chandrakant Bhardwaj
1416006
E&E-6

2.  1.Application of Thermistor:-
(a) Principle Of Thermistor
(b) Thermistor’s Applications
2.Strip Chart Recorder:-
(a) Block Diagram
(b) Working Function Or Working Principle
3. CRO Probes:-
(a) Introduction
(b)Types & Examples
INDEX

3.  Thermistor is special type of resistor, whose resistance varies
more significantly with temperature than in standard resistors.
Generally, the resistance increases with the temperature for
most of the metals but the thermistors respond negatively i.e.
the resistance of the thermistors decrease with the increase in
temperature.
This is the main principle behind thermistor. As the resistance
of thermistors depends on the temperature, they can be
connected in the electrical circuit to measure the temperature
of the body.
Thermistor

4.  Thermistors are also commonly used in modern digital
thermostats and to monitor the temperature of battery
packs while charging.
 PTC thermistors were used as timers in the degaussing
coil circuit of most CRT displays. A degaussing circuit
using a PTC thermistor is simple, reliable (for its
simplicity), and inexpensive.
 We regularly use NTC thermistors in automotive
applications.
 We can also use NTC thermistors to monitor the
temperature of an incubator.
Application Of Thermistor

5.  Thermistors are also commonly used in modern digital
thermostats and to monitor the temperature of battery
packs while charging.
 NTC thermistors are used in the Food Handling and
Processing industry, especially for food storage systems
and food preparation. Maintaining the correct
temperature is critical to prevent food borne illness.
 We can also use PTC thermistors as heater in automotive
industry to provide additional heat inside cabin with diesel
engine or to heat diesel in cold climatic conditions before
engine injection.
 We can regularly use the Thermistors in the hot ends of 3D
printers; they monitor the heat produced and allow the
printer’s control circuitry to keep a constant temperature
for melting the plastic filament.

6.  BLOCK DIAGRAM:-
Strip Chart Recorder

7.  It records one or more variables with respect to time. It is a
X-t recorder.
 A strip chart recorder consists of:
 1. A long roll of graph paper moving vertically.
 2. A system for driving a paper at some selected speed. A
speed selector switch is generally provided. Chart speed
of 1-100 m/s are usually Used.
 3. A stylus driving system which moves the stylus in a near
exact replica or analog of the quantity being recorded.
 A range selector switch is used so that input to the
recorder drive system is with in the acceptable level.
Working Function

8.  INTRODUCTION:- Cro is very useful and versatile
laboratory instrument used for display , measuremets
and analysis of waveforms and other phenomena in
electrical and electronic circuit.
Cro probes performs very important function of
connecting the test circuit to the oscilloscope without
altering , loading or otherwise disturbing the test
circuit.
CRO PROBES

9.  The probes are three different types of probes:-
(A) Direct reading probe
(B) Circuit Isolation Probe
(C) Detector probe
(A) DIRECT READING PROBE:-
This probe is the simplest of
the probes and uses a shielded co-axial cable.
It avoids stray pickups which may create problems when low
level signals are being measured.
It is usually uses for low frequency or low impedance circuits.
However in using the shielded probes,the probe shunt
capacitance of the probe and cable is added to the input
impedance and capacity of the scope.

10.  (B) ISOLATION PROBES:-
Isolation probe is ued in order to avoid the undesirable circuit
loading effects of the shielded probe.
The isolation of the probe, which is used along with the
capacitive voltage divider,decreases the input capacitance
and increases the input resistance of the ocilloscope.
(C) DETECTOR PROBES:-
The detector probe function to separate the low frequency
modulation component from the high frequency carrier.
The amplitude of the modulator carrier is proportional to the
response of the receiver to the much high frequency carrier
signal which is displayed on the oscilloscope by rectifying and
bypassing action.

11.  So after doing this presentation , I will like to conclude that :
 Thermistor , it is the resistance which varies by decrease with
the increase in temperature . And its application are like in
modern digital thermostats ,automotive applications ,etc.
 Strip chart recorder is a device which is used mainly used to
get a hardcopy of the measurement i.e , by the working
principle of it . Used in measuring vibrations , ph , etc.
 CRO probes performs very important function of connecting
the test circuit to the oscilloscope without altering , loading or
otherwise disturbing the test circuit.
CONCLUSION