Manometers

The device for measuring pressure such as atmospheric pressure or the pressure of a gas or liquid is known as manometer. There are many types of pressure manometer devices, comprising mercurial manometers and digital manometers. Just by using a length of a glass tubing a simple mercury manometer can be created. Usually this type is sealed at one end and then mercury is placed in the tube in such a way that no remains at the end of the tube. The tube, which is bent into U shape sealed at the one end and leaving the other open is used in this type of manometers.

The U shaped manometer and the pressure measurement

When, the mercury in the tube moves to the bottom of the U shape, vacuum results in the sealed end of the tube. Here at this end, there is no air to produce a downward pressure on the mercury. The open end is being exposed to the air or the gas and thus the pressure is measured. The dissimilarity in the height of the mercury in the two sides of the manometer offers the measurement that will facilitate the pressure of the gas to be decided.

Measurement in millimeters and Torr

 This kind of measuring the pressure was used in the early days of research and the pressure was stated in units of millimeters of mercury. For instance, a pressure of 1mm Hg means the pressure that will result in a difference of 1millimeter in a mercury manometer tube. In recent days experts have attributed a name for the measurement for pressure as the ‘torr’. And 1 torr of pressure is equivalent to 1mm Hg.

Further, in measuring pressure manometers will also be used to measure the spread at which a stream of air is flowing. The movement of the air creates a region of lower pressure than a usual atmospheric air. The open should be kept in a place where there is airflow to decide the speed of the moving air by measuring how the pressure changes.  

The usage for many related fields

In modern applications a digital manometer is used to measure the pressure. Manometers are nowadays also being used with medicine in cases such as for blood pressure, and small manometers are used to monitor the pressure in patient's airways. The usage also finds relevance in the industrial settings like in avionics and in whether forecasting.

Questions:

• What are manometers?
• List down some of the uses of manometers.