6

1. Zero-power Resistance of Thermistor: R

2. B-Constant

..............(1)

R: Resistance in ambient temperature T (K)

(K: absolute temperature)

B: B-Constant of Thermistor

as (1) formula

B=

............(2)

3. Thermal Dissipation Constant

When electric power P (mW) is spent in ambient

there is a formula as follows

..................(3)

C: Thermal dissipation constant (mW/

°C)

Thermal dissipation constant is varied with dimensions,

measurement conditions, etc.

4. Thermal Time Constant

Period in which Thermistor's temperature will change

63.2% of its temperature difference from ambient

Resistance vs. Temperature

!Basic Characteristics

!Performance

Thermal Time Constant

Item

Resistance

Condition

Measured by zero-power in specified ambient temperature.

Rated Electric Power

Shows the required electric power that causes Thermistor's temperature to rise to a specified temperature by self heating,

at ambient temperature of 25

°C.

Permissive Operating Current

It is possible to keep Thermistor's temperature rising max. 1˚C.

Thermal Dissipation

Constant

Shows necessary electric power that Thermistor's temperature rises 1˚C by self heating.

It is calculated by next formula (mW/˚C).

B-Constant

Calculated between two specified ambient temperatures by next formula.

B =

1/T

P

C =

T

−20

Temperature (˚C)

0

20

40

60

80

120

100

1

B=3450

B=3900

B=4100

Basic Characteristics

Time

63.2%

X

• This catalog has only typical specifications because there is no space for detailed specifications. Therefore, please approve our product specifications or transact the approval sheet for product specifications before ordering.

Please inquire about test conditions and ratings.

• This catalog has only typical specifications because there is no space for detailed specifications. Therefore, please review our product specifications or consult the approval sheet for product specifications before ordering.

R44E.pdf

Feb.21,2011