Fluke 8508A - Entering or Editing the Characteristics of a PRT to Non-Volatile Store

4
Remote Operations Using the IEEE 488 Interface
Syntax Diagrams of Major 8508A Functions
Entering or Editing the Characteristics of a PRT to Non-volatile Store
The following commands are used to construct a
PRT identity and set associated
parameters and coefficients.
PRT_CHR
phs identity
,
STD_PRT
CVD_ALPHA
CVD_DIN
CVD
,
TWO_WR
THREE_WR
FOUR_WR
adj357f.eps
Entering or editing PRT characteristics
This command with its associated parameter can be used to enter characteristics of a new
PRT identity to the non-volatile store.
Identity
This is a string value and thus must be enclosed in double , limited to 17 characters.
STD_PRT
This selects the conversion algorithm to be used. The ITS90 conversion is used for a
standard PRT.
CVD_ALPHA
This selects the conversion algorithm (Callender Van Deusen) to be used and the method
for expressing the conversion coefficients (R
zero
α β δ).
CVD_DIN
This selects the conversion algorithm to be used and the method for expressing the
conversion coefficients (R
zero
A B C ).
CVD
This selects the conversion algorithm to be used and requires only the R
zero
value. The
other parameters are set to a default value.
TWO_WR / THREE_WR / FOUR_WR
This specifies the type of connection and thus the measurement method.
phs
PRT_COEF
phs identity
,
,
adj358f.eps
Entering or Editing PRT Coefficients
This command with its associated parameter is used to enter the coefficients, or to edit
the existing coefficients of a PRT with a known identity. NOTE that when editing all the
parameters MUST be given in the correct order. The numbers entered are associated in
the following manner:
• For CVD only one number is required for the R
zero
value.
• For CVD_DIN the first number is the R
zero
value, the second is the A coefficient, the
third the B coefficient and the fourth is the C coefficient.
• For CVD_ALPHA the first number is the R
zero
value, the second is the α coefficient,
the third the β coefficient and the fourth is the δ coefficient.
• For STD_PRT the first number is the resistance of the probe at the triple point of
water. The second is the a+ value (a
7
). The third is the b+ value (b
7
). The fourth is the
c+ value (c
7
). The fifth is the a- value (a
4
). The sixth is the b- value (b
4
).
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