Escort 3016B - Manual (Page 137)

17 Appendix
Page 8
Pl = + 0.25 C (accuracy of standardisation )
Pz = + 0.25 C (zero accuracy )
Pd = 0 (no zero offset)
Pm calculation :
Slope calculation at 240 C : 321 + (301-321) x (240-200) / (400-200) so 317 V/ C
Pm = 210 / 317 = + 0.66 C
Max. total accuracy:
Pt = + 0.25 + 0.25 + 0.66 = + 1.16 C
17.4. Accuracy class index of class
This is one of the essential concepts of the C.E.I. recommendation: it is intended to alleviate the
listing of the specifications. In order to do so, it introduces the concept of ACCURACY CLASS,
which is determined here as CLASS C INDEX.
The normalised values of the index of class are: C = 0.1 ; 0.25 ; 0.5 and 1.
The intrinsic error (in the reference conditions) does not exceed C % (the manufacturer can also
specify this limit of the intrinsic error as an absolute value (for example 5 microvolts) for the first
ranges).
When one of the influence variable varies within the nominal range of use, variations (of the
measured value) do not exceed:
- C % for the position, for the magnetic induction from outer origin and for spurious
voltages
- 0.5 C% for the power supply
- 0.3 C% according to the class index for the room temperature (0.15 % for the 0.25 class).
Moreover, the range of insensitivity must not exceed:
- C% in the reference conditions
- 1.5 C% for the maximum resistance of the outer circuit of measure
- 2 C% for the spurious voltages
-
Eventually, no overvalue should exceed 2 C% (4 C% for the limits of the power supply).