How to assess risk when using an altimeter in wilderness?

Understanding Altimeter Limitations

When using an altimeter in the wilderness, it’s essential to recognize its limitations. Mechanical altimeters can be affected by temperature changes, while digital altimeters may be influenced by battery life and calibration issues. For example, a mechanical altimeter’s accuracy can decrease by 1-2 feet for every 10°F change in temperature. Always check your altimeter’s manual for specific temperature ranges and calibration procedures.

Calibration and Cross-Checking

To ensure accurate readings, calibrate your altimeter before use, and recheck its accuracy after significant changes in temperature or humidity. This involves setting the altimeter to the current atmospheric pressure, which can be obtained from a reliable source such as a weather report or a GPS device. Cross-check your altimeter’s readings with other navigation tools, such as a GPS device or a map with contour lines. For example, if you’re using a GPS device to track your elevation, compare its readings with your altimeter’s output to ensure consistency.

Best Practices for Safe Navigation

When relying on an altimeter for navigation, always maintain a healthy dose of skepticism and verify your position with other methods, such as triangulation with visible landmarks or using a compass. Additionally, be aware of the altimeter’s error margin and plan your route accordingly. For instance, if your altimeter’s error margin is 100 feet, plan your route to include a buffer zone of at least 200 feet to ensure safe navigation.