About time weighted average variables

The time weighted average variable allows you to calculate the time weighted average of a tag or an expression for a specific period of time. The calculation is similar to average, however it considers the duration the tag or expression was a particular value. This type of variable needs at least one capture condition so it can calculate the result between the two captures.

For example, the following table includes three capture points with their corresponding duration.

To calculate the time weighted average, the values are multiplied by the durations. The results are added and then divided by the total duration.

((30 * 60) + (100 * 20) + (50 * 40)) / (60 + 20 + 40) = 48.33

Whereas if you were to consider a simple average of the values, the result would be 60.

(30 + 100 + 50) / 3 = 60

Example scenarios

You can use this variable to calculate:

• The time weighted average of a production rate, which needs to be used in multiple reporting points. The variable must have the same capture condition as the reporting points.

• The time weighted average of a slurry's solids% in a pipeline to be used in the calculation of dry tonnes in a material movement. The variable must have the same capture condition as the material movement.

Related topics

• Add and configure a time weighted average variable

• Time weighted average variable properties