Micromod MOD: 1800P - MOD 30ML Identity Module (Version 2) Algorithms, Tables and Sequential Logic Functions - Manual (Page 41)

Logic Functions - Book 2
LINEARIZATION BLOCK
8-33
Square and Modified Square
Square and modified square linearizations are used when an input signal is proportional to the
square root of the measured value. The modified square curve is shown in Figure 8-18.
The algorithm is performed on a normalized value (0.0-1.0). If the input signal is not already
normalized, the input range attributes are configured to normalize the input value as follows:
normal value = (INPUT _ INLOW) / (INHI _ INLOW)
If the input value is less than 0, the absolute value is used, the square is calculated, and the
final result value (after engineering units conversion) is set to –(result value).
For the SQUARE linearization type, the result is equal to the input squared. The MODIFIED
SQUARE of the normalized value is calculated as follows:
•
If the input value is greater than 0 and less than or equal to 0.01, the result value is equal
to the input value.
•
If the input value is greater than 0.01 and less than or equal to 0.1572, the result value is
equal to:
0.01 + ((INPUT _ 0.01) * 0.1)
•
If the input value is greater than 0.1572, the result value is the square of the input value.
The result of the square algorithm is a normalized value. This result can be scaled to other
units by configuring the output range attributes. The output would then be calculated as
follows:
Output = (OUTHI _ OUTLOW) * (normal value) + OUTLOW
Square Root and Modified Square Root
Square root and modified square root linearizations are used when an input signal is
proportional to the square of the measured value. The modified square root curve is shown in
Figure 8-19.
The algorithm is performed on a normalized value (0.0-1.0). If the input signal is not already
normalized, the input range attributes are configured to normalize the input value as described
for square and modified square).
If the input value is less than 0, the absolute value is used, the square root is calculated, and
the final result value (after engineering units conversion) is set to -(result value).
For the SQUARE ROOT linearization type, the result is equal to the square root of the input.
The modified square root of the normalized value is calculated as follows:
•
If the input value is greater than 0 and less than or equal to 0.01, the result value is equal
to the input value.
•
If the input value is greater than .01 and less than or equal to .0247, the result value is
equal to:
0.01 + ((INPUT _ 0.01) * 10.0)
•
If the input value is greater than .0247, the result value is the square root of the input
value.
The result of the square root algorithm is a normalized value. This result can be scaled to
other units by configuring the output range attributes. The output would then be calculated as
shown above for the square algorithm.