Data Sheet

149 05/02
c) Calculation of resistance tolerance by means of equation (3):
If the R/T characteristics are computer-stored, the resistance tolerances for all temperatures can be
easily determined by an appropriate calculation program.
1.3 Temperature tolerance
With given resistance tolerance, the temperature tolerance is determined as follows:
α Temperature coefficient at T in %/K (see R/T characteristic)
|
∆R
T
/R
T
| Resistance tolerance in % at T
The following applies to the example given under point 2:
The calculation mode given here is to be regarded as an approximation of actual conditions (B value
temperature-dependent, tolerances symmetrical); nevertheless, the results obtained are sufficiently
accurate for practical applications.
∆ R
35
R
35
---------------
5 1,5 3930
1
35 273,15+
()
------------------------------------
1
100 273,15+
()
---------------------------------------
–
èø
æö
⋅⋅
+%=
5 5895
1
308,15
------------------
1
373,15
------------------
–
⋅+%=
5 5895 0,00056529⋅+()%=
5,0 % + 3,3 % = 8,3 %=
∆ T
1
α
---
∆ R
T
R
T
-------------
⋅= (4)
∆T 100 °C()
1
2,9
--------
5K=1,72K
⋅=
∆T35°C()
1
4,1
--------
8,3 K = 2,02 K
⋅=
Standardized R/T Characteristics