Texas Instruments CBL Guide Book

64 CBLé System Guidebook
Conversion Equation
CMD4 Type, Form, and Restrictions
The conversion equations listed in
CMD4
(page 47) have certain
computational limitations. In particular, some operations are not defined
for negative arguments.
The overall accuracy of the CBL does not guarantee that a precisely zero
volt input will not be read as a slightly negative number. Therefore, if
you are using a conversion equation that has this limitation, use input
voltages with minimum values above zero.
If an equation encounters an error, e.g., division by zero or a power of a
negative number, that operation causes an overflow value (9.9
E
31) to be
carried in the computation. The end result will likely be a very large
value. This allows the sampling process to continue without interruption,
but extremely large results (9.9
E
99) should be interpreted as an
indication that the restrictions listed below have been violated.
Equation Type Equation Form Restrictions
1 Polynomial (order:
n=1-9)
K
0
+ K
1
X + K
2
X
2
+...+ K
n
X
n
*
2 Mixed polynomial
(order: m=0-4, n=0-4,
m+n>0)
K
-
m
X
-m
+...+ K
-
1
X
-1
+ K
0
+ K
1
X +...+
K
n
X
n
Xƒ0
3 Power K
0
X
(K
1
)
X>0
4 Modified power K
0
K
1
(X)
K
1
‚ 0
5 Logarithmic K
0
+ K
1
ln(X) X>0
6 Modified logarithmic K
0
+ K
1
ln(1/X) X>0
7 Exponential K
0
e
(K
1
X)
*
8 Modified exponential K
0
e
(K
1
/X
)
Xƒ0
9 Geometric K
0
X
(K
1
X)
X‚0
10 Modified geometric K
0
X
(K
1
/X)
X>0
11 Reciprocal logarithmic [K
0
+ K
1
ln(K
2
X)]
L
1
K
2
X>0
12 Steinhart-Hart model [K
0
+ K
1
(ln 1000X)+K
2
(ln 1000X)
3
]
L
1
X>0
*No restrictions other than overflow.

Texas Instruments CBL Specifications

General

Brand	Texas Instruments
Model	CBL
Category	Calculator
Language	English