There are many different types of machinery and equipment that rely on some sort of pressure to be generated in order to work. Be it in your car, home or at an industrial plant pressure plays an important role in our everyday lives.
In order to keep equipment and tools working properly the pressure in them must be at a certain level and what better instrument to check it with than a manometer? A pressure gauge manometer is able to measure pressure levels as well as pressure difference. Manometers work by measuring pressure against a certain volume of liquid in different units including pascals, bars, millibars and even mmHg.
Uses of Manometers
Gas
There are different applications for manometers although all they can do is measure pressure. However, since pressure applies to more than just one aggregate state, a proper pressure manometer can be easily used throughout different fields and industries. For instance, a handheld manometer can be used to measure gas pressure in piping systems as well as in hazardous environments.
Water
A manometer can also be used to measure water pressure. You have to make sure that the unit you go for is waterproof enough to be able to survive the environment you're going to be using it in. If you're going to be surrounded by chemicals and other hazardous fluids you must ensure that you're using the right type of manometer.
Air
Air pressure is pretty easy to measure with a manometer since it can be determined rather easily with Venturi or pilot tubes. It's just that you need to check the air temperature to make sure that the manometer you're using can deliver accurate results at said temperature.
Types of Manometers
U-Tube
Some of the simplest manometers are U-tube manometers as they are analogue devices that can measure only a difference in pressure. You need two pressure levels from tubes, orifices or nozzles and the help of flow meters since u-tube manometers are quite inaccurate in comparison to more modern counterparts.
Bourdon-Tube
A Bourdon-tube manometer that works without being reliant on electricity. This mechanical pressure gauge is made of a bent tube that looks like an arc. As the pressure inside it increases the coil is unwinded which is picked up by a pointer connected to a handle. As the tube stretches and shrinks the level of the pressure changes.
Digital
Most of today's manometers are digital and because of that, they are able to provide more accurate results. This also makes them more straightforward in terms of the measurement process as fewer moving parts are involved. You only get a pressure transducer which deflects when exposed to pressure and then it's converted into a value.
Inclined
An inclined manometer is one that is angled and can provide accurate measurements when it comes to low pressure in both liquids and gasses. But unlike a digital pressure manometer, an inclined one is less versatile and not as easy to use despite being highly accurate.
Micro
With micromanometers, you can measure small pressure differences. This is because micromanometers are extremely sensitive and can detect the slightest change in pressure between two sources. They can also be used for calculating volumetric flow rates and velocity.
What to Look for in a Manometer
Size
The nominal size or diameter of the device is going to depend on your expectations and needs. If you want a more capable pressure gauge manometer that is able to do various measurements in different environments usually larger ones are better since they are equipped with beefier and better components. Smaller more portable units are less capable than larger ones but you can find bang-for-buck models too.
Range
The pressure range of a manometer is what determines how versatile it is as a wider range means you have a device that is more capable of detecting larger pressure differences. If you don't need a handheld manometer with as extensive of a pressure range you can easily go for a less capable one thus a more affordable option too.
Liquid-Filled vs No-Liquid
The reason behind there being a liquid-filled version of a regular (no liquid) manometer is to prevent any vibrations or pulsation from rendering inaccurate results. They can be filled with either glycerin or silicone and the idea of a liquid-filled pressure gauge manometer is to be able to get readings quickly when conditions are not ideal. But keep in mind that these manometers are prone to leakage.
Connections
In order for a manometer to work you need to have the right connections at the right location. For instance, you have lower-mount manometers that are able to hook up to a fixture or pipe more easily than back-mount manometers as you have better access and view of the fitting. This way you're able to connect the device more easily especially if there's enough clearance.
