MULTIFUNCTION 4-IN-1 ALTIMETER BAROMETER Function: 1. Barometer altimeter, built-in sensitive air pressure measuring device, can measure the real-time atmospheric pressure value of a given location. 2. There is no need for batteries and chargers, easy to maintain and repair, can predict future weather changes according to the measured barometric pressure. 3. Due to the principle that the height is inversely proportional to atmospheric pressure, it can be used to measure the relative height; after adjusting the height value, the height can also be measured in real time. 4. Mini and compact design, durable and portable for convenient carrying, can be hung on a key chain, pants or backpack, suitable dial size for easy reading. 5. Widely used in atmospheric pressure measurements, as well as in outdoor applications such as mountain climbing, hiking, fishing, but not recommended for geological research. Specification: Item Type: Altimeter Barometer with Compass Thermometer Material: plastic Scale: Height: 0-5000 m/0-5468,1 yards Air pressure: 600-1000 HPa Temperature: -30-50 Resolution: approx. 20 m/21,9 yards Size (L. x W x H ): approx. 85 x 68 x 28 mm/3,3 x 2,7 x 1,1 inches Disc diameter: approx. 60 mm /2.4 inch Storage conditions: Temperature: -30 -65 ; Humidity: less than 90% The compact and small size thermometer are mainly used for decoration, the sensitivity is limited and not suitable for situations requiring high accuracy. Physical principles of product design and application: (1) Air pressure decreases as altitude increases; (2) The change in atmospheric pressure will cause a change in weather and this change will be indicated on the dial of this altimeter via a very accurate transmission device. This device can accurately measure position height (absolute height), altitude difference, atmospheric pressure and predict weather changes. Take advantage of the introduction: 1. Measurement of absolute height: The altimeter must be initiated before use (see the figure showing the operation), that is, set the altimeter number to the actual local altitude. In addition, changes in air pressure and weather will continue to affect the altitude value, so it is necessary to constantly compare the reference altitude values when climbing or walking. Example: Check with the Meteorological Office that the height of the starting point A is 200 meters, set the altimeter hand on a scale of 200, and after reaching position B, the scale of the dial is 1500, then the height of the starting point B is 1500 meters. 2. Relative height During climbing or walking, if you want to measure the height of your surroundings, follow these two steps: (1) Initiate the altimeter at the point of departure, that is, set the hand on a scale of 0; (2) When traveling or at the destination, the scale value displayed on the dial is the height value relative to the place of departure. Example: Set the altimeter to scale 0 at starting point A, and when you reach position B, the dial scale is 1500, which means that B is 1500 meters higher than A. List of packages: 1 x Compass 1 x Barometer 1 x Carabiner 1 x Manual