# How To Check The Barometer

The barometer is a mercury device invented back in 1644 and is still used to measure atmospheric pressure. Mercury barometers are considered the most accurate and are used at weather stations. At home, a mechanical barometer is usually sufficient.

## Instructions

### Step 1

Aneroid is one of the types of barometers. This device is a mechanical barometer that works without the use of liquid (mercury). Inside the cylindrical "box" there is a base made of corrugated metal. A vacuum is created there, due to which the size of the "box" changes when the atmospheric pressure changes. With increasing pressure, the "box" increases in size, with decreasing - it decreases. At the same time, its dimensions directly affect the movement of the spring, which, through a system of levers, moves the arrow indicating the pressure measurement scale. At home, as a rule, these types of barometers are used.

### Step 2

If your home barometer shows results that differ from those stated in the weather forecast on TV or on the Internet, do not rush to panic and consider your device as faulty. The fact is that atmospheric pressure changes depending on geographic coordinates: the weather station is located far from your home and the pressure may indeed slightly differ. In addition, it should be remembered that atmospheric pressure differs depending on the height above sea level in proportions of 1 atm. water column = 10 meters, so take into account the floor on which you live.

### Step 3

Oddly enough, it is possible to check the operation of the barometer and aneroid only in the vicinity of other pressure measuring devices. When placed side by side, they will show the same value on the barometric pressure scale. So go with your frustrated device to a barometer store or the nearest weather station.

### Step 4

When comparing the results of machines to determine pressure, consider the difference in performance. If your device shows the pressure incorrectly, do not write it off as unusable. Just measure how many units on the scale differ from the data of both barometers. The next time you measure atmospheric pressure, simply add or subtract your meter's error to the result.