NR55300299 Datasheet, PDF (1/7 Pages) AVX Corporation – NTC Leadless Disc Thermistors

NTC Leadless Disc Thermistors
This type of product is widely used in automotive and
consumer applications.
They are assembled in custom-probes for sensing the
temperature of liquids (water, oil, ...), gases or surface of any
other component.
The metallization covers completely the surfaces of the
thermistor.
The particularly flat and smooth surfaces ensure an excellent
electrical and thermal contact under pressure.
Types
NR
Metallization
Physical data (dim. in mm)
Marking
Operating temperature
Values and tolerances
D
E
On package only / On parts upon request
-40°C to +200°C
Custom - designed products defined with:
D ± D R₁ ± R₁/R₁ at T₁
E ± E R₂ ± R₂/R₂ at T₂, . . .
DESIGN OF THE THERMISTOR
Choice of the resistances
If the application is to measure the temperature around a
defined point, a unique nominal resistance can be chosen
(for example, among standard values of the ND range prod-
ucts presented on pages 20 to 24).
When it is required to measure the temperature over selected
ranges T₁ –T₂ , T₂ –T₃ , ..., the corresponding resistance
R₁ , R₂ , R₃ , ..., must be such that they can be located
on the R (T) characteristic of an existing NTC material
(for example among standard materials whose R (T) are
displayed on pages 29 to 33).
The resistances must also be compatible with the resistivity
of the material and the dimensions of the thermistor.
Choice of the tolerances
The precision of the temperature measurement determines
the calculation of the tolerance on the resistance:
⌬R/R = ␣ (%/°C). ⌬T (°C)
For example, the NTC NR55--3049-99, using “N5” material
(R (T) characteristic displayed on page 31), requires a preci-
sion of 1°C over the temperature range 110°C - 120°C.
The tolerances can be calculated:
⌬R_110°C /R_110°C = 1°C* 2.91%/°C = 2.91%
⌬R_120°C /R_120°C = 1°C* 2.76%/°C = 2.76%
*For your specific requirements, please consult us.
HOW TO ORDER
NR55 - - 3002 - 99
Type
P/N Code
1