17 Appendix
Page 7
17.3.AccuracyofthePT100measurements
Themeasurementinaccuraciesthereafteraregivenasmaximumvalues:typicalvaluesare2to3
timesless.
Themeasurementaccuracyintemperatureisthe sumofseveralpossiblesourcesofinaccuracy:
Pl:accuracyofstandardisation
Pz:zeroaccuracy
Pm:accuracyofthemeasurementoftheequivalentvoltage
Pd:accuracyofthemeasurementoffsets
Thetotalaccuracyisthen:Pt=Pl+Pz+Pm+Pd
Fortherecorder:
Pl= 0.25 CforthePT100
Pz= 0.25 CforthePT100
Pd= 0.10%oftheoffset
Pm=giveninthetables
Measurementaccuracy:Pm
ThemeasurementaccuracyPmdependsonthevoltagerangeusedbytheappliance. The
measurementerrorindegreeswillthenbethemeasurementerrorinvoltagedividedbythe slopein
V/ C.
Forallthevoltageranges,theaccuracyis+/-0.1%+/-10 V.
Slopedependiingoftemperature:
Temperature ( C) -200-1000200400600800
Slope ( V/ C) 378354342321301281260
Equivalentvoltagemeasurementaccuracyat 0 C:
R
a
n
ge
T
e
m
p
e
r
a
t
u
re
T
e
n
s
i
on
M
ax
e
r
r
or
(
V)
M
a
x
E
r
r
or
(
C)
20
10
20
0.
06
50
20
30
0.
09
100
50
60
0.
18
200
100
110
0.
32
500
200
210
0.
60
1000
500
510
1.
50
2000
1000
1010
3.
00
R
a
n
ge
EXAMPLEOFACCURACYCALCULATION
Themeasurementisabout240 Cmadewiththe500 Crange,centeredon 0 C(nonzerooffset)
withaPT100probe.
Pt=Pl+Pz+Pm+Pd