3.3.5. Reference altitude and barometric pressure

To ensure that the altimeter shows correct readings, you first need to set an accurate reference altitude. To do this, go to a location whose altitude you have checked, for example, with the help of a topographical map, and set the reference altitude to match the map reading.

NOTE: If you do not know the current altitude, go to the Position display and check the altitude with the GPS. The longer the GPS is on, the more accurate the altitude reading will be.

If you do not have accurate altitude information, you can use the current sea-level barometric pressure as the reference value. Your Suunto X9 will provide you with the current sea-level pressure after you have switched the GPS on. Depending on the quality of satellite reception this may take few minutes. Suunto X9 has a factory-set reference altitude that corresponds to the standard barometric pressure (1013 hPa/ 29.90inHg at sea level).

Setting the reference altitude

To set the reference altitude:

1.In the Set menu, Reference is the first menu item. Press ENTER to select it. The reference menu opens.

2. Altitude is the first menu item. Press ENTER to select it. The Altitude display opens. The previously set altitude is highlighted.

3.Change the altitude with UP/DOWN and press ENTER. The reference altitude is now set and you return to the

Reference menu.

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Suunto X9_en manual Reference altitude and barometric pressure, Setting the reference altitude