Mercury Barometer The pressure of the atmosphere at

Mercury Barometer § The pressure of the atmosphere at any point is due to the weight of overlying air. Pressure at the surface of the earth is normally measured by the mercury barometer and is expressed in inches of mercury. The mercury barometer consists of an open dish of mercury into which the open end of an evacuated glass tube is placed. Atmospheric pressure forces the mercury to rise in the tube. The great the pressure, the higher the column rises.

Unit of Measure § Pressure § § Inches of Mercury ("Hg) § § The unit used to measure the length of a column of mercury in the barometer. Millibar (mb) § § Force per unit area The pressure exerted on an area of 1 square cm by a force of 1000 Dynes. Hectopascals (h. Pa) § One hectopascal equals one millibar.

ICAO - International Civil Aviation Organization § a) Mean sea level pressure § 29. 92”Hg § 1013. 2 mb § 1013. 2 h. Pa or 101. 32 k. Pa § b) Mean sea level temperature § 15°C § c) Air is a perfectly § gas rate is d) § dry Lapse § 1. 98°C/1000 ft

Density is mass per unit volume. Pressure and Density are directly proportional. As density increases, so does pressure.

NOTE: You must use the buttons in the Confirmation Stage

Meteorology Atmospheric Pressure and Density Let's try a few review questions on Meteorology: Question #1 - Describe the ICAO mean sea level temperature? A 15 o. C B 1. 98 o. C C 2. 0 o. C D 29. 92 o. C

Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . .

Flying Scholarship Program That answer is correct. Let's move on. . .

Altimeter Setting The barometric pressure reading is used to adjust the altimeter for variations in existing atmospheric pressure or to the standard altimeter setting. If set to the existing pressure, it will read the true elevation of the airport above sea level. It is measured in inches of mercury.

Meteorological Aspects of the Altimeter When flying from an area of high pressure to an area of low pressure, the altimeter will read higher than what the aircraft is actually flying. L H Intended Path th a P l a Actu HIGH TO A LOW, LOOK OUT BELOW

Meteorological Aspects of the Altimeter When flying from an area of low pressure to an area of high pressure, the altimeter will read lower than what the aircraft is actually flying. H L th a P l a u t c A LOW TO A HIGH, CLEAR BLUE SKY Intended Path

NOTE: You must use the buttons in the Confirmation Stage

Meteorology Atmospheric Pressure and Density Let's try a few review questions on Meteorology: Question #3 - The altimeter reads the altitude above level. A Aerodrome B Area C Sea D Ground

Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . .

Flying Scholarship Program That answer is correct. Let's move on. . .

Meteorology Atmospheric Pressure and Density Let's try a few review questions on Meteorology: Question #4 - What unit of measure is the altimeter expressed in? A Inches of Mercury B Isobar C kilopascals D Both A and C

Flying Scholarship Program I’m afraid that answer is incorrect Let's try again. . .

Flying Scholarship Program That answer is correct. Let's move on. . .

Meteorology Atmospheric Pressure and Density Congratulations!! You have now completed the Atmosphere Pressure and Density lesson of the Meteorology Module. Of course, this lesson is always available to you for future reference if required. You are now ready to move along to the next Meteorology lesson you have not completed or to any other module you wish. You can advance to the Self Test Module if you feel ready to challenge the final exam. Good Luck!