Meazure obtains position information from the computer operating system. This information is reported to Meazure in pixel units. To display measurements in units other than pixels, Meazure must convert from pixels using the screen resolution. By default, Meazure uses the screen resolution reported by the operating system. However, this value is inaccurate because it does not reflect the physical dimensions of your display screen(s). Meazure allows you manually determine an accurate resolution for each display screen connected to your system. It is highly recommended that you calibrate Meazure the first time you use it and anytime you change a screen’s pixel dimensions (e.g. going from 1024 by 768 to 1280 by 1024 pixels).

To access the resolution calibration panel select the Preferences item on the Edit menu then select the Calibration tab on the Preferences dialog.

The resolution calibration panel displays the calibration state for the screen on which it is displayed. In a multiple screen environment, the calibration panel must be dragged to the screen whose resolution is to be calibrated. The identification of the screen is displayed with the title of the calibration panel frame.

The resolution calibration panel allows you to select whether to use the operating system values for the horizontal and vertical screen resolutions or to use a manual setting of these values. It is highly recommended that you select the manual setting. Before describing the calibration process, the following terms need to be defined:

Screen Resolution - The resolution is the number of pixels per inch or centimeter along the screen. The screen can have a different resolution in the horizontal and vertical directions (e.g. 90 pixels/inch by 96 pixels/inch).

Screen Size - The size of the screen is the number of pixels in the horizontal and vertical directions (e.g. 1280 by 1024 pixels).

Screen Dimensions - The screen dimensions are the length in inches or centimeters in the horizontal and vertical directions (e.g. 13 inches by 10 inches).

There are three methods for manually setting the screen resolution: direct resolution entry, direct dimension entry, or slider calibration. To use any of these methods select "Set manually". The resolution can be calibrated using either English or Metric units. Use the inch and centimeter radio buttons to select the units to use for calibration. This selection affects only the calibration units and does not change the measurement units.

Direct resolution entry - If you know the exact screen resolution, use this method to directly enter the horizontal and vertical values using the "Rx" and "Ry" text fields. Resolution values must be specified in pixels per inch or pixels per centimeter depending on the calibration units selected.

Direct dimension entry - Using a ruler, you can measure the horizontal and vertical dimensions of the screen. You can then enter these dimension values using the "W" and "H" text fields. The dimension values must be specified in inches or centimeters depending on the calibration units selected.

Slider measurement - This method uses a ruler in conjunction with the horizontal and vertical sliders on the panel to set the resolution. Place a ruler on the screen and align it with the zero position on one of the sliders. If resolution calibration is being performed in inches, move the slider until it points to the one inch mark on the ruler. For metric calibration, move the slider until is points to the two centimeter mark on the ruler. Repeat this process for the remaining slider.

Note that when the operating system resolution is used, a warning button appears on the Screen Information section of the program display. Pressing this button displays the resolution calibration panel.