7.3.2.1 Selecting the Characterization
The followingcommands can be used to select the probe characterization and
coefficients:
P=90<EOS> selects the ITS-90 characterization
P=68<EOS> selects the IPTS-68 characterization
P=R<EOS> or P=S<EOS> selects the standard Callendar-VanDusen
characterization
R0=<value><EOS> sets R0or R(0.01C) depending on the selected charac-
terization
AL=<value><EOS> setsαfor the Callendar-Van Dusen or IPTS-68 char-
acterization
DE=<value><EOS> setsδfor the Callendar-Van Dusen or IPTS-68 char-
acterization
BE=<value><EOS> setsβfor the Callendar-Van Dusen characterization
A4=<value><EOS> setsa4for the ITS-90 or IPTS-68 characterization
B4=<value><EOS> setsb4for the ITS-90 characterization
C4=<value><EOS> setsc4for the IPTS-68 characterization
An=<value><EOS> setsa6,a7,a8,a9,a10, or a11 for the ITS-90 character -
ization.nis a number from 6 to 11.
Bn=<value><EOS> setsb6,b7,b8, or b9for the ITS-90 characterization. n
is a number from 6 to 9.
Cn=<value><EOS> setsc6, or c7for the ITS-90 characterization. nis 6 or
7.
D6=<value><EOS> setsd6for the ITS-90 characterization
SC=69<EOS> or SC=90<EOS> sets the temperature scale for the
IPTS-68 characterization
7.3.2.2 Testing the Characterization
The followingcommand can be used to test the probe characterization:
CO=<value><EOS> returns a temperature calculated from resistance
The 1502A willrespond with a temperature value computed from the given re-
sistance value.The temperature is given in the currently selected unit. As an ex-
ample, if the Callendar-VanDusen characterization is selected with IEC-751
coefficientsand the selected unit is Celsius, sending this command with a resis-
tancevalue of 138.5 will return a temperature value of 100.0°C.
7.3.3 Sample Commands
The following commands ralate to the measurement process.
1502A Thermometer Readout
User’s Guide
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