Units of measure in formula data references
- Last UpdatedMay 21, 2025
- 1 minute read
- PI System
- PI Server 2018
- PI Server
When working with formulas and units of measure (UOM), you need to configure the equation inputs and the output with the correct UOM:
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For the attributes in the equation, use the UOM that the formula expects (NOT the units the attribute is already in).
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For the calculation result, specify the UOM in which you want the result to appear. This must be consistent with the UOMs for your inputs (attribute values).
Example of UOM in a formula data reference
Consider the following formula configuration for converting volume and density into mass:
V=Volume;UOM=L;D=Density;UOM=kg/L;[V*D];UOM=kg
The units of measure for the inputs and outputs are consistent: (L*kg/L = kg). This formula works on any input attributes or output attributes, regardless of the attribute's unit of measure, as long as they have a unit of measure of the correct class specified.