Today, a wide variety of various devices is used, which really measure even the most incredible characteristics. But what is an altimeter? In the article we will get acquainted with its description, varieties and other interesting information.
What is an altimeter?
Altimeter - a device for measuring the level of height. It is used mainly by pilots, climbers, geologists and scientists. In relation to the aircraft is a flight navigation device. In addition, the device is popular in everyday life. You can easily buy or order a watch with an altimeter barometer.
The following concepts will be full synonyms of a word:
- altimeter;
- radio lot;
- altimeter;
- radio altimeter;
- photoalmeter.
By the way, previously an altimeter was called a simple goniometer tool for determining the height of stars, planets and other celestial bodies.
Types of instrument
The following instrument forms are known:
- Aneroid altimeter barometer. Since pressure, on the contrary, decreases with increasing height, the scale of the device can be calibrated for its (height) measurement. One of its varieties is a parachute altimeter. It is conveniently mounted on the arm, allows you to observe the height and atmospheric pressure in free fall and with the parachute open. There are electronic devices that can give signals when reaching specified heights.
- Radar Altimeter More typical for aviation. The device works like this: measures the delay time of the reflection of the radio signal that is sent to the ground, and based on these data it shows the flight altitude. The device is more accurate in measurements, however, it is used at low altitudes - at more significant, a powerful source of radiation of magnetic waves and equipment capable of eliminating interference are required.
- GPS devices. Speaking of what it is - an altimeter, one cannot but mention these devices. The design measures the distance to 4-6 satellites that are in well-known and strictly defined orbits. Based on a number of mathematical calculations, the device determines the position of the object in space, including the height above a specific point on the surface of the earth or sea level.
- Gamma ray altimeters. The basis for such devices is gamma radiation. It is applied at low altitudes. It is mainly used to provide soft landing for spacecraft.
Device application
Although almost everyone can buy watches with an altimeter, this device is still more applicable in aviation. Let's see how it is used by pilots:
- Before the flight, a weather report is required. For an altimeter, atmospheric pressure information is important.
- The dispatcher speaks of the pressure in the area of the aerodrome only above sea level. This value is entered by the pilot into the instrument. Thus, all aircraft receive universal altitude indicators.
- However, at different points on the route, the pressure will vary. Is it because of this that pilots need to constantly listen to summaries and change data for the device? No, the problem was solved much easier. After the "transition height", the pilots set the altimeters to the same pressure values. Each aerodrome has this value. Roughly about 18,000 feet above the ground.
- What are the indicators of universal pressure? This is 760 mmHg. Art.
- As soon as the pilot falls below the "transition height", the controller should inform him of the current atmospheric pressure in the area of the aerodrome.
- When lower than 2500 feet, the barometric altimeter is turned off and the radio altimeter is activated.
History of creation
The device was invented by Paul Collsman, originally a mechanic in aviation devices. At that time, there were already many different devices to help control aircraft, but still they were not enough for a "blind flight".
In 1928, P. Kollsman quit his permanent job and founded his own company Kollsman InstrumentCo. In the same year he created a barometric altimeter, which is used today.
And in 1929 the first so-called “blind flight” of 15 miles took place. Portholes in the cockpit were tightly curtained. He could navigate only according to the readings of the instruments. Among the latter was the Kollsman altimeter.
That's all we wanted to tell about the device. Now you know what it is - an altimeter, its varieties. As well as the practical use of the device.