Datasheet

Chip NTC Thermistor
RND is a trademark of Distrelec
Test and Measurement Procedures
Unless otherwise specified, the standard atmospheric conditions for measurement/test as
• Ambient Temperature: 20±15℃
• Relative Humidity: 65±20%
• Air Pressure: 86 kPa to 106 kPa
If any doubt on the results, measurements/tests should be made within the following limits
• Ambient Temperature: 20±2℃
• Relative Humidity: 65±5%
• Air Pressure: 86 kPa to 106 kPa
Inspection Equipment
• Visual Examination: 20x magnifier
• Resistance value test: Thermistor resistance tester
Electrical Test
Item
Test Methods and Remarks
Nominal Zero-Power Resistance
at 25
℃
(R25)
Ambient temperature:
25 ± 0.05
℃
Measuring electric power: ≤0.1 mW
Nominal B Constant
25 ± 0.05
℃
, 50 ± 0.05℃, 85 ± 0.05℃
Measure the resistance at the ambient temperature of 25 ± 0.05℃, 50 ± 0.05℃ or 85 ± 0.05℃
B(25-50℃) =
B(25-85℃) =
T: (K) Absolute temperature (K)
Thermal Time Constant
The total time for the temperature of the thermistor to change by 63.2% of the difference from
ambient temperature T0 (
℃) to T1 (℃) by the drastic change of the power applied to
thermistor from non-zero Power to Zero-Power state, normally expressed in second (S)
Item
Test Methods and Remarks
Dissipation Factor
The required power which makes the NTC thermistor body temperature raise 1
℃ through self-
heated, normally expressed in milliwatts per degree Celsius (mW/℃). It can be calculated by the
following formula
Rated Power
The necessary electric power makes thermistor’s temperature rise 100℃
by self-heating at
ambient temperature 25℃
Permissible Operating Current
The current that keep body temperature of chip NTC on the PC board in still air rising 1°C by self-
heating