Industries have many requirements for measuring pressure. Applications include measuring fluid levels, tank pressures, flow rates or hydraulic system pressures. For the measurement of low pressures, one such device is called a pressure manometer.
Manometers were first used shaped as a U-tube – is simply a tube filled with liquid. The unit functions on the principles of gravity and the density of the liquid being measured. A ruler or scale is used to measure the height of the fluid in the U-tube and this directly reads the pressure present. Pressure ranges for manometers are as small as a few inches of water column to several feet.
Measuring Air Flow
A pressure manometer is often used to measure the air-flow speed. Moving air creates a force that is proportional to velocity. This force, typically just a few inches of water column, is applied to the manometer for measurement and then converted to flow by a simple calculation. The measurement of flow in air in ducts and ventilation systems is one such use of the manometer.
Another use of manometers is the measurement blood pressure using an air cuff. Low pressure manometers may also be used to measure the flow and pressure in a patient’s airways. Manometers have also been used in industrial settings, wind tunnels, and the measurement of atmospheric pressure for weather forecasting.
There are many manometer designs to choose from. Most manometers available now are digital models. This is because fluid manometers using mercury are considered a toxic hazard. At Validyne, our manometers work by using a pressure transducer instead of a column of fluid to make the pressure measurement. Digital manometers can be utilized with any equipment that relies on gas or liquid to operate.
Manometers can also isolate system pressure problems from barbecue grills to propane and natural gas. The HVAC industry, on occasion, will use these units to troubleshoot air conditioning and heating systems. Manometers can also be used to troubleshoot a wide variety of pneumatic or low-pressure gas systems.
Advantages of a Pressure Manometer
There are several advantages of using electronic manometers. An electronic manometer is portable and more compact than the old fluid-filled types. The electronic manometer is more accurate and provides a greater resolution than older versions, and a digital display is easier to read.