Sometimes barometer readings may not be the same as the barometric pressure reported by local stations or airports. This slight difference is due to elevation, and barometric reading is usually taken at sea level. So it does not mean that your barometer has a different lesson that there is something wrong with it; it depends on several factors such as elevation and temperature. But how do you know if your barometer is not working?
How to test an Aneroid barometer
An aneroid type barometer measures changes in atmospheric pressure mechanically and without using liquids like mercury. An aneroid barometer makes use of a hollow metal diaphragm that moves a needle indicating atmospheric pressure.
The sea-level atmospheric should be about 30 inches, and the needle will rarely reach 30.5 or 29.5. Typically, the atmospheric pressure will only change one to two-tenths of an inch. When an aneroid type barometer leaves the factory, it is set at sea-level.
These are the steps to determine if your Aneroid barometer is working or not :
- Place the movable pointer or index hand over the indicator needle and wait a few days to see whether the indicator needle moves. When the atmospheric pressure is steady, the indicator needle will not move. Wait for weather changes over a few days to determine if the indicator needle is moving correctly. If the indicator needle does not move after observation, check the local weather reports and look at the barometric pressure. Your barometer should move according to the changes reported in the weather reports.
- Place the barometer in a sturdy clear plastic bag and make sure there is air trap inside the bag. Closed the bag by holding the end or tying the opening.
- Increase the pressure inside the bag by pushing into the bag or squeezing it. Make sure you do not push or squeeze the barometer itself. The indicator needle to should move as the pressure in the bag increases.
- If the indicator needle still does not move, return it to the supplier for repairs.
How to test a mercury barometer
A mercury barometer measures atmospheric pressure using a column of mercury. The mercury barometer measures the changes in the height of the column due to changes in atmospheric pressure. But how do you know if your mercury barometer is working correctly?
The mercury barometer can be a long and thin device with a glass tube or a wheel-shaped barometer with a round dial. But the test remains the same.
- Hang the barometer on the wall by suspending it using a hook or nail.
- Gently move the bottom of the barometer on the wall while raising it to about 45 degrees angle.
- If you are using a wheel type mercury barometer, the indicator needle should move quickly in a clockwise direction as you move the instrument to a 45-degree angle.
- If you are using barometer with mercury in the glass tubing, as you move the device to a 45-degree angle, the mercury inside will rise quickly to fill the tube’s tip, leaving no air bubble.
- If the barometer does not do #3 and #4, the mercury barometer is not working correctly.
Remember to store your barometer in a room with shutters or blinds Newcastle as opposed to curtains to ensure it is well ventilated and is not exposed to direct sunlight.