Solartron Mobrey 3595 4C, User Manual

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3595 4C User Manual Part Two IMP Commands
35952350 (CH01/AA)
1-47
UT
(User Thermocouple linearisation)
UT I a
5
– a
0
b
5
– b
0
Where: < I > defines the user thermocouple as Thermocouple ‘1’ or ‘2’
a
5
– a
0
are IEEE 754 floating-point numbers for the coefficients of a fifth-order polynomial
b
5
– b
0
are IEEE 754 floating-point numbers for the coefficients of a fifth-order polynomial, but
are the inverse of the a
5
– a
0
polynomial.
Function: This command is used to apply a user-defined linearisation to a thermocouple measurement.
The aim is to cover any thermocouple type not covered by the polynomials available in 3595
IMP types 1H and 1J). (Channel modes 390 – 394 use the coefficients defined by
UT1 .
Modes 3A0 – 3A4 use coefficients defined by UT2 .)
The computation of reference junction
2
compensation requires both the linearisation
polynomial and its’ inverse. User-defined thermocouple linearisation acts in the same way as
predefined thermocouple linearisation with respect to the
AM , TR and TC commands. (See
mode codes 310 – 3A4 in Table 1.7, page 1-14)
Notes: If a thermocouple is measured and the corresponding linearisation equation has not been
defined, the error code FF82
xxxx is returned instead of the 4-byte result.
See also: CH MO
CH PL
(Post Linearisation)
CH n PL I
Where: n is an integer that defines the channel number, in the range 1
≤
n
≤
18
< I > defines the user-defined linearisation equation to use, ‘1’ or ‘2’ (‘0’ disables post
linearisation on channel n)
Function: Enables conversion of a measured parameter into alternative units, with the linearisation
function:
0
5
5
2
2
3
3
4
4
5
5
a x a x a x a x a x a y
+ + + + + =
Where x is the input parameter and y is the output . The coefficients used are those defined
by the PL command.
Note: The CH PL command can be used with channel unit conversion. Post linearisation is applied
first and then the unit conversion.
See also: PL
2
Historically, called the ‘cold’ junction. Now known more accurately as the reference junction. Similarly, the ‘hot’ junction is now
known as the measurement junction.