Roadway Standard - Mounting Height Equation

The BSEN and Australia standards define Observer distance for the Veiling Luminance and Threshold Increment as a function of luminaire mounting height. The standard formula is:

2.75 x (MH - 1.5) meters

If you choose to use a formula in a custom standard that will define Observer location based on luminaire mounting height, you may do so for any Calculation Metric, not just Veiling Luminance w/ TI, provided the metric calls for an Observer. (Not applicable for illuminance metrics.)

To define an Observer position this way:

- Select the Calculation Metric that it will apply to.
- Click on the Observer tab.
- For Observer Position, select Dynamic and then Based on MH Equation.
- Click in one of the equation cells (Meters or Feet).
- The MH Equation Syntax shows the formula that will be used to calculate Observer position based on mounting height. Working in either the Meters or Feet column, enter the appropriate values that will place the Observer the desired distance from the beginning of the calculation grid.
- The MH Equation that you are creating will be displayed at the bottom of the dialog, in both Meters and Feet versions.
- Click OK to return to the Roadway Standards dialog and continue to create your custom standard.