air pressure
When air pressure goes up, the liquid in a mercury barometer goes down. This is because as air pressure increases, it pushes the mercury in the tube to rise, indicating higher pressure.
Air pressure is measured in different ways. Two common ones are PSI (pounds per square inch) or a barometer which measures in column inches of mercury. As we know the barometer goes up and down with weather so the air pressure goes up and down. The highest barometer reading ever recorded is about 32 inches or just over 15.6 PSI. The lowest barometer reading ever recorded was 25.69 in the middle of a hurricane so this is not typical but equates to about 12.5 PSI. These are all sea level readings. So we need an average, or normal. The standard is a barometer of 29.92 which equates to about 14.7 PSI, again being a sea level reading. With that standard the pressure at Denver is 12.1 PSI or a barometer of about 24.63. At this pressure water boils at about 202F instead of 212F.
Barometer's measure air pressure and the Earth's air pressure at a certain place is due to the weight of the air above it. So the higher you go the air pressure drops because there is less air above you pushing down with its weight.
The chamber of a barometer will contract as air pressure goes up. A rise in air pressure pushes the mercury column downward, causing the chamber at the top to become smaller.
The connection goes like this:The barometer is a device for measuring air pressureAs a storm approaches your location the reading on barometer will dropThe storm may be a lightning stormLightning is static electricity
during cold weather like rain storms or snow storms the barometer goes down. During warm weather the barometer goes up.
When a barometer goes down, it indicates a decrease in atmospheric pressure, which often suggests that a storm or inclement weather is approaching. Lower pressure can lead to rising air, resulting in cloud formation and precipitation. Conversely, a rising barometer typically signifies improving weather conditions. Thus, monitoring barometric changes can help predict shifts in weather patterns.
it goes up. :D
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A rising barometer indicates improving weather conditions, such as clearing skies and less precipitation. Conversely, a falling barometer suggests worsening weather, like approaching storms and increasing wind. By monitoring these changes in barometric pressure, you can anticipate shifts in the weather patterns.
Very simply put, cold air is denser than warm air - thus as air of differing temperature passes over you (or rather your barometer) the barometric pressure will change. The arrival of warm air will cause the barometric pressure to fall and as warm air holds more moisture than cold air a falling barometric pressure will herald the arrival of rain. Conversely, if the pressure rises this will indicate some nice sunny days to come Further, if the pressure falls (or rises) fast, then there are likely to be strong winds.
A low oil pressure reading when idling for a 1986 Fiero is normal. As long as the oil pressure goes back to normal when the car is being driven, there should be no problem. If it is not, then the oil pressure sensor or the oil sending unit should be looked at.