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Metal Oxide Varistors
NTC 温度传感器
NTC 热敏电阻器是一种以过渡金属氧化物为主要原材料制造的
半导体陶瓷元件。它具有电阻值随着温度的变化而相应变化的特
性。即在一定的测量功率下,电阻值随着温度上升而下降。利用
这一特性,可将 NTC 热敏电阻器及其温度传感器应用在测控温,
温度补偿,和抑制浪涌电流等场合。
Thermistor is a ceramic semiconducting element made from
exorbitant oxides materal. It has the feature that the resistance
changes according to the ambient temperature. Namely, their
resistance declines with the rising of ambient temperature at a
determinate measuring power. With this feature NTC thermistor
and temperature sensor can be applied in the situation of
temperature measurement and control, compensation and
surge current protection.
NTC 热敏电阻器及其温度传感器的主要参数:
Main techno-Parameter of NTC Thermistor:
零功率电阻值 RT
Zero Power Resistance RT
在规定温度下,采用引起电阻变化相对于总的测量误差来说可以
忽略不计的测量功率测的的电阻值
At rated temperature ,it is the resistance measured by the
measuring power which causes the resistance change that can
be ignored relative to the whole measuring error.
额定零功率电阻值 R25
Rated Zero Power Resistance R25
也称标称电阻值,通常是指 25℃时测得的零功率电阻值
Also Known as Nominal Resistance,is the zero power
resistance measured at 25℃
B 值
B Value
B 值是负温度系数热敏电阻器的热敏指数,他被定义为两个温度
下零功率电阻值的自然对数之差与这两个温度导数之差的比值
B Value is the thermel exponent of negative temperature
coefficient thermistor, which is defined as the ratio of the
difference between the napierian logarithm of zero power
resistance at two temperatures to the difference between the
temperatures’ reciprocal.
T1T2
/( T1 T2 )= T2 T1
RT1
RT1
1
1
B=In
-
In
R
R
T 2
T 2
式中:RT1-温度为 T1 时的零功率电阻值
RT2-温度为 T2 时的零功率电阻值
In the equation: RT1-The zero power resistance at T1
RT2-The zero power resistance at T2
除非特别指出,B 值是由 25℃(298.15K)和 50℃(323.15K)的
零功率电阻值计算而得到的,B 值在工作温度范围内并不是一个
严格的常数。
Unless the particular indication, B value is figured out from the
zero power resistance at 25℃(298.15K) and 50℃(323.15K)
and B value is not a rigorous constant in the range of operating
temperature.
零功率电阻温度系数αT
Temperature Coefficient of Zero power Resistance αT
At rated temperature, it is the ratio of the zero power resistance
change rate with temperature to the zero power resistance
itself.Namely:
指在规定温度下,热敏电阻器的零功率电阻值随着温度的变化率
与它的零功率电阻值之比。
dRT
1
B
α = R dT
=- T 2
T
式中:αT-温度为 T 时的零功率电阻温度系数
RT-温度为 T 时的零功率电阻值
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