Calculate General Photometrics

The Calculation General Photometrics command is used to calculate point-by-point photometrics inside of general calculation areas. All of the settings available in the command are the same as the Calculate Egress Photometrics command. This sections describes the options available for these two commands.

The two commands use different light fixtures and different settings on the light fixtures. See the General Versus Egress Photometrics section for more information on these differences.

To run general photometric calculations, go to

Ribbon: DM Electrical->Point-by-Point Photometrics-> dm_elec-photo-calc-ribbon Calculate General Photometrics

Pulldown Menu: DM Electrical->Point-by-Point Photometrics->Calculate General Photometrics

Calculate Photometrics Dialog Box


Contour Level 1 - 10: Enter the foot-candle level at which to draw contours. You can have up to 10 contours. Contours set to 0 will not be drawn.

Color: The color of the contour. Press the Set button to open the AutoCAD Select Color dialog box.

Show FC Levels: Whether foot-candle levels are shown on the drawing. If this is checked, the foot-candle levels will be displayed in the calculation area after the calculation is finished.

Show Contours: Whether contours are shown on the drawing. If this is checked, contours will be displayed in the calculation area after the calculation is finished.

Decimal Places on Drawing: The number of decimal places to include in the foot-candle levels on the drawing.

Decimal Places in Schedule: The number of decimal places to include in the foot-candle levels on the schedule. If the Decimal Places on Drawing is less than the Decimal Places in Schedule, the smaller Decimal Places on Drawing will be used for the Maximum Foot-candles and the Minimum Foot-candles values in the schedule.

Base Unit: Whether the base unit for your drawing is an inch or a foot.

Inch: One unit on the drawing corresponds to one inch. The standard base unit for architectural drawings.
Foot: One unit on the drawing corresponds to one foot. The standard base unit for civil drawings.

If you are uncertain which setting to use, go to your drawing in AutoCAD. Type UNITS at the command line. Note the current Type setting, then change it to Decimal. Ignore the Insertion scale setting. It might be set to Feet or Inches, but it is not a reliable means of determine which setting to use for photometric calculations. Press the OK button to close the dialog box.

Type DIST at the command line and measure the distance of an item you know the length of on your drawing, such as a parking space, door on the building, or the total length of the site.

The distance will be displayed on the command line. Press F2 to view the AutoCAD Text Window if the distance is not visible. Use this answer to set the Base Unit setting. For example, if measuring the width of a standard door, the Base Unit should be set to Inch if a distance of 36 displayed, or Feet if a distance of 3 is displayed.

Use the UNITS command to reset your Type setting if desired.

Reflections: Whether the calculation includes reflections from walls and ceilings.

No Reflection: No reflections are included in the calculation. This option is faster, though the calculated values will be slightly lower than reality for inside calculations and near walls outside.
Single Reflection: Light is reflected once during the calculations. This option takes longer, but results in higher values near solids. The light is reflected off of one surface to the ground. Light that hits a second surface is not reflected. For example, light that goes from the light to a wall to the ground is included. Light that goes from the light to the floor to a wall, then back to the floor, is not included.

Zoom to Schedule After Insertion: Whether the current view will be moved to the schedule associated with the calculation area.

Edit Title, Column Labels, and Column Order: Press this button to modify the layout of the photometric schedule on the drawing. See the Edit Calculation Schedule List section for more information.

Calculating Photometrics

After all of the information has been entered, press the OK button.

If there is only one calculation area in the drawing, the foot-candle levels in the area will be calculated.

If there is more than one calculation area in the drawing, you will be prompted to specify which area to calculate.

Select calculation area to calculate / <Calculate all boundaries>:

Select calculation area: Select a point inside an area to calculate the foot-candle levels in just that area.

Calculate all boundaries: Press ENTER to calculate the foot-candle levels in all areas on the drawing.

The foot-candle levels and contours in the area that is calculated will be updated. The values in the corresponding photometric calculation schedule will also be updated.

Related Options

Schedule title justification: Sets the justification for the schedule title.

Schedule column label justification: Sets the justification for column headings.

Schedule title continued label: Sets the label added to the schedule title for continued sections.

There are several options that set the default values for this dialog box. See the General Point-by-Point Photometrics Options and Egress Point-by-Point Photometrics Options sections for more information.

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