When going to the mountains, take with you an altimeter (altimeter), which will allow you to be always informed about the altitude of your location. This is important to know not only for orientation, but for control over your physical condition.
mechanical or electronic altimeter
Use an altimeter to determine the height of the surrounding mountains. The mechanical device is based on the simple principle of atmospheric pressure versus altitude. The pressure drops with increasing altitude, the spring in the device unwinds and the arrow shows the height with an accuracy of 1 m, depending on the number of divisions on the dial. Now electronic altimeters have appeared.
Measure the height with a mechanical device. Set the arrow to 0 before the start of the ascent, the device will show you the height in meters to which you climbed. Please note that weather conditions greatly affect the readings of the device. If the atmospheric pressure changes abruptly during for, a readjustment must be carried out.
Use electronic altimeters, which are often built into your watch and are very handy on the go. In special devices for determining the height, not only the height above sea level is indicated, but also the air temperature and time. For use, it is necessary to set the starting point of measurement, as in a mechanical device, and fix the point at an altitude (such devices are also based on the principle of the relationship between atmospheric pressure and altitude above sea level).
Unfortunately, it is not possible to use the systems for determining the absolute, and not relative to the height (as in the devices mentioned above), until they are released for general use. These are devices that use the reflection of radio waves, gamma radiation, as well as GPS receivers. An electronic altimeter measures the reflection time of a sent wave from the surface of the earth or water and calculates the distance. A GPS receiver determines a point in space using signals it receives from Earth satellites. It more accurately determines the height, since these signals are independent of weather conditions and from measuring the distance to the earth's surface.