GE Vivid i, User Manual

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Measurement and Analysis
Vivid i User’s Manual
143
2378958-100 Rev. 02
About units
Be aware of the following:
• All units 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 desired unit the
resulting value should use. E.g. if Y in the formula Y=f(x) is
to be displayed in cm, enter cm in the
Unit field.
The Unit field is case sensitive, make sure to enter the
exact unit as shown in the table below (Alternative unit
column).
2. When creating the formula, be sure that all parameters (all
the X’s in Y=f(x)) are in SI units. All default parameters in
the system are in SI units.
If the resulting value of a user-defined formula is set to be
displayed in a unit that is not SI, you must apply the correct
conversion factor to all the parameters (X’s).
Example: if you have the formula Y=a*X and you set the
formula result to be in cm, you have to convert the
parameter X from meter (default SI unit) to cm by dividing
the parameter by 100. The formula with a result in cm
should be defined as follow: Y=a*X/100.
Calculation SI Alternative unit
Time s
Ratio %
Frequency bpm
Angle rad
Distance m
Velocity m/s
Acceleration
m/s
2
Area
m
2
Volume
m
3