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NTC
( Negative Temperature Coefficient ) Thermistors
are thermally sensitive resistors which exhibit
a decrease in resistance value with increase in
its body temperature. |
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NTC
Thermistor Terminology |
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Zero
- Power resistance value - The Zero-power
resistance is the DC resistance value of
a Thermistor measured at a specified temperature
with a power dissipation by the Thermistor
low enough that will result in not
more than 0.1% change in resistance value. |
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B-Value
constant - B-Value is a material constant
of a Thermistor in K which reflects the
slope of the Temperature / Resistance curve.
Higher the B value, higher the thermal sensitivity
of the Thermistor. B-Value is different
for each type of Thermistor material and
temperature range. Most Thermistor manufacturers
report B-Values between 2500K - 5000K. |
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Thermal
Dissipation Constant - Heat flow characteristics
in NTC Thermistor elements and component
assemblies are governed by Thermistor shape
factors, material properties, thermal coupling
conditions and temperature differential
of the element to its surroundings. The
thermal dissipation constant of a Thermistor,
D.C(mW / 0C) equals the energy or power
required to raise the temperature of the
Thermistor element by 10C. |
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Thermal
Time Constant - The Thermal time constant
is the time taken by the Thermistor to change
63.2% of the total difference between its
initial temperature and that of its surroundings
when dissipating no power. The time constant
is very much dependent on the size and finish
of a Thermistor. |
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©
EXA Thermometrics India Pvt. Ltd. No.181,
Lake Shore Road, BTM Layout – II Stage, Bangalore:76,
Tel
:+91-80-40698200, +91-80-40698210\211 |
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