Are altimeters AGL or MSL?

As Scott said, AGL means Above Ground Level, while MSL is Mean Sea Level, meaning the altitude above sea level. Altimeters are generally referenced to sea level because the ground level keeps changing as you move.

How does a modern altimeter work?

The altimeter measures the height of an aircraft above a fixed level. The instrument senses this by taking the ambient air pressure from the static port. Inside the altimeter is a sealed disc called an aneroid, or bellows. As the aircraft goes up, the pressure inside the case decreases and the bellows expand.

What is standard altimeter?

The standard altimeter 29.92 inches Mercury (“Hg.) setting at the higher altitudes eliminates station barometer errors, some altimeter instrument errors, and errors caused by altimeter settings derived from different geographical sources.

What are the types of altimeter?

There are four main types of altimeter:

• Barometric altimeter.
• Radio altimeter.
• GNSS (GPS, Galileo, etc).
• Laser altimeter.

What source of pressure does the altimeter use?

static pressure
The altimeter uses static pressure as its source of operation. Air is denser at sea level than aloft—as altitude increases, atmospheric pressure decreases.

What is FT AGL?

AGL, or above ground level, is the distance that an object is above the ground below it. For example, if you are standing on the roof of a building that is 100 feet tall, you are at 100 feet AGL. MSL, or mean sea level, refers to the distance an object is above sea level.

What is pressure altimeter?

: an altimeter using an aneroid to determine altitude by measuring differences in atmospheric pressure — compare absolute altimeter.

What is a pressure altimeter?

noun Meteorology. an aneroid barometer adapted for measuring altitude by converting the indicated atmospheric pressure to altitude according to a standard relationship.

What is a servo altimeter?

The principle of the servo altimeter, introduced by Smiths Industries in 1958, was that aneroid capsules were relieved of all but the lightest mechanical work involved in the electrical detection of their position. The operation of the instrument was performed by an electrically powered servo.