GE Vivid S70, User Manual

Page: 549 / 709

Measurement Package
Vivid S70 / S60
–
User Manual
12-29
BC092760-1EN 01
About units
Be aware of the following:
• All formulas are calculated in SI units (see table below).
• If no unit is specified in the
Edit formula
window when
defining a formula, the displayed value will be in SI unit.
To define a different unit
1. When creating a formula, enter the unit to use when
displaying the formula output. E.g. if Y in the formula Y=f(x)
is to be displayed in cm, enter cm in the
Unit
field (see
Figure 12-15
on page 12-26
).
The
Unit
field is case sensitive, make sure to enter the exact
unit as shown in the table below (Alternative unit column).
2. The output of a formula must always be in an SI unit (see
table below). Conversion to the specified display unit is then
done automatically.
Example: an user wants to add a regression formula for
estimating a length
B from a measured length A , both in cm.
The formula is: B = 2.4 + 1.1*A.
•
As A is a measurement value the system will enter the
formula in the SI unit for length (m). The formula
expects A in cm, and to get that,
A must be multiplied by
100:
B = 2.4 + 1.1*A*
100
• The formula now gives B in cm. Converting the output
from cm to the SI unit (m), is done by dividing by 100:
B = (2.4 + 1.1*A*100) /100
The output is now in m, and by entering this formula into the
system the user gets the expected result. Measuring an
A of
2 cm gives: B = (2.4 + 1.1*0.02*100)/100 = 0.046 m.
Before display of the value it is converted according to the
specified display unit (cm), and the system displays 4.6 cm.
If the selected display unit was set to mm the formula would
give the exact same output, 0.046 m, but the automatic unit
conversion would now instead give a displayed value of
46 mm.