Magnetic Heading

The RD8200SG has an integrated magnetic compass that provides a value for heading, which is used to calculate the most accurate GNSS position of the buried utility.

With MAG_H set to ON the offset between the locator GNSS antenna and the bottom of blade of the locator is automatically removed from the GNSS data so that the point will be from the bottom of the locator and not the GNSS antenna.

If MAG_H is set to OFF, all GNSS points will be from the locator GNSS antenna.

The magnetic heading information (‘MAG_H’) can be found in the ‘INFO’ section of the RD8200SG locator menu.

The subsections of the MAG_H menu are described below:-

• ON – turns on the magnetic heading compensation for the GNSS position (default state).
• OFF – turns off the magnetic heading compensation for the GNSS position.
• CHECK – displays the current heading value under the bar graph (figure 8). This is useful to compare heading accuracy with another physical or digital device. The error is also shown in the bottom right (figure 8).
• RESET – selecting reset and then ‘YES’ will reset the calibration of the magnetic compass.
  Over time the accuracy may degrade, or environmental/location factors may impact the accuracy and require a re-calibration. Once selected, the user will need to slowly spin the locator in a circle whilst 50 reference points are taken. Whilst this process is occurring the number of points taken is displayed in the bottom right of the display (figure 7a and 7b).
• EXIT – exits from this part of the menu.

Figure 7a	Figure 7b	Figure 8