Omega CL3001, Руководство пользователя, Страница: 27 / 104

To use a custom RTD curve:
a) Select RTD measure or source mode as described in the
preceding sections.
b) Press the key until the USR_DEF type is selected.
c) Press the key to display the curve selection prompt
"RTD CUSTOM (1-5)".
d) Press the numeric key corresponding to the custom RTD
curve to be used.
e) At the "SET(1)/RECALL(2)" prompt, press to recall the
custom RTD curve coefficients.
f) To use a different custom RTD curve, press the key
twice to display the USR_DEF selection prompt.
The USR_DEF function of the CL3001 uses the Calendar-Van Dusen
equation for sourcing and measuring custom RTD's. The C
coefficient is only used for the subrange -260 to 0 degrees Celsius.
Only the A and B coefficients are needed for the subrange 0 to 630
degrees. The R0 value is the resistance of the probe at 0 degrees
Celsius.
All 5 of the custom RTD curves are set to PT385 at the factory, as
shown in Table 2.
Table 2 - Default Custom RTD Coefficients
Curve Subrange R0 Coefficient A Coefficient B Coefficient C
1 0 to 630 100 3.9083e10-3 -5.775e10-7 0
2 -260 to 0 100 3.9083e10-3 -5.775e10-7 -4.183e10-12
3 0 to 630 100 3.9083e10-3 -5.775e10-7 0
4 -260 to 0 100 3.9083e10-3 -5.775e10-7 -4.183e10-12
5 0 to 630 100 3.9083e10-3 -5.775e10-7 0
Table 3 shows the coefficients for RTD types PT391 and PT392. The
C coefficient is only used for temperatures below 0 degrees Celsius.
Table 3 - Other Common RTD Coefficients
RTD Type R0 Coefficient A Coefficient B Coefficient C
PT392 100 3.9848e10-3 -5.87e10-7 -4.0e10-12
PT391 100 3.9692e10-3 -5.8495e10-7 -4.2325e10-12
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