What is a manometer?
A manometer is a device that measures pressure either against a fixed reference (gauge or absolute pressure) or between two ports (differential). In its simplest terms, pressure is the force exerted by a substance (in this case gas or liquid) on the surface unit, which is due to the effect of gas or liquid on the force of gravity. The manometer can be measured in different units including load, millibar, pascal and mmHg depending on the specific model.
Manometers work by measuring pressure against the volume of a liquid. In principle, they are used to measure pressure differences. With an analog manometer, the liquid being measured is added to a tube. The liquid level is then determined by the liquid pressure and the liquid height, as indicated by the barometer.
Topics covered in this article:
- Types of manometers
- What can a manometer be used for?
- How to choose the right manometer
- Manometer brands
- Compare manometers
- Frequently Asked Questions
Types of manometers
Pressure measurement has been necessary for a wide range of industries and applications for many years. Even before modern electronic manometers were invented, similar instruments were used to measure pressure. As a result, there are several different types of manometers available today, including analog and digital models.
Some different types of manometers can be identified below:
Absolute : This means that the pressure gauge gives zero pressure in complete vacuum using the absolute reference scale.
Gauge : Gauge manometer uses ambient or atmospheric pressure as a zero reference.
Differential : These manometers use differential pressure, which means that they use the pressure difference between two adjusted points.
The following sections describe some types of manometers in more detail:
The U-tube manometer is one of the simplest types available. They are an analog manometer commonly used as a differential pressure gauge with a flowmeter and are often used to measure pressure differences in pitot tubes, nozzles and vents in airflow and ventilation systems.
U-tube manometers are made up of relatively small parts and are usually one of the cheapest types of manometers, but the trade-off is that accuracy can be poor. As a result, the u-tube manometer should not be used to measure particularly low pressure differences, and an alternative manometer should be used instead. Finally, the viewing angle is key when working with u-tube manometers to ensure maximum reading accuracy.
Sloping manometers are commonly used to measure liquids and gases that have very low pressures . The angular design of the sloping manometer makes this feature especially suitable for this role and allows accurate measurements. Nevertheless, digital manometers are often preferred today due to their high accuracy and ease of use.
Digital manometers have largely become the norm and are now widely used by professionals for a variety of measurement applications. Unlike analog manometers, digital models contain pressure converters that deflect under pressure. The device then converts the deflection into a detectable electrical parameter and calibrates it to a pressure gauge, thus performing the measurement.
Accurate and easy-to-read digital manometers can be used for multiple fluids and can also be calibrated to ensure a higher degree of accuracy. Absolute digital manometers have a single connection port – reading gauge relative to atmospheric pressure and absolute reading relative to vacuum. It should also be noted that some models allow communication between the manometer and the computer to quickly and easily download stored or live measurements and recordings.
Digital manometers are useful for a number of reasons, including:
- Easy to read and use
- Avoid relying on manometric fluids
- High degree of accuracy
What can a manometer be used for?
Manometers are primarily used to measure the pressure of a process relative to the atmosphere or other processes. They are versatile instruments and are used in many different industries and applications.
Some key points for a manometer are described below:
Manometer for gas pressure
Digital gas manometers are used by heating and boiler engineers for a variety of purposes, including gas pressure monitoring in piping systems. It is important to make sure that a pressure gauge used for gas pressure is ATEX approved, as this certification ensures that the instrument is suitable for use in hazardous environments.
Manometer for water pressure
When using a manometer to measure water pressure, the model used should be suitable for liquids to prevent possible damage to the device. Likewise, if the liquid contains chemicals or other potentially hazardous substances, you should be aware of the damage that may occur if the manometer is used improperly. In addition, excessive pressure on the manometer may cause subsequent readings to be incorrect due to bending or internal rupture of the diaphragm, so it is essential to use the correct instrument with caution.
Manometer for air pressure
Digital air pressure manometer is used in many process industries. They can also be used with pitot or venturi tubes to determine the velocity of air flow in the tube. Before use, it is important to check the air temperature and note the maximum average temperature in the manual for the specific manometer model.
How to choose the right manometer?
Despite the different types of manometers, it is important to choose the right instrument for your needs. There are several important factors to keep in mind when choosing a manometer because answering the following questions will help you determine the type of manometer.
Key considerations include:
- Maximum pressure required
- Differential, gauge or absolute
Reputable manometer brand
The manometer is available from a wide range of leading brands and suppliers, giving you a lot of freedom to choose the model that suits your needs. Some of the major brands are listed below:
Wika-dwyer- rs pro-druck
Ultimately, the best manometer largely depends on the intended application and any specific task requirements. It is always advisable to do a thorough research before deciding on a manometer, as it is very important to make sure that it is compatible with the job it is doing.
To compare sphygmomanometers as a general rule, u-tube manometers are cheaper and more sophisticated, although they are less accurate than other alternatives. Comparison of digital and analog manometers You will find that digital models are better for measuring smaller differences because analog instruments are affected by the viewing angle. Analog manometers are better for fast signal fluctuations .
What does a manometer measure?
A manometer measures the pressure difference either between a process and a constant reference pressure (gauge pressure or absolute pressure) or between two ports (differential manometer).
How to use a manometer?
Because different types of manometers are available, it is recommended that you refer to your manometer manual for instructions.
Advantages and disadvantages of manometers
Digital manometers are very accurate and precise as well as easily portable.
Not all manometers are suitable for use in any environment. To prevent possible damage or incorrect readings, you must make sure that your environment is compatible with the manometer before use. In addition, increased pressure can damage the internal diaphragms.
How accurate is the manometer?
Digital manometers are more accurate than analog versions, but it is always advisable to check the manufacturer’s instructions for the accuracy of a particular instrument.
How do manometers measure pressure?
There are different methods depending on the specific type of manometer. Digital manometers usually use a pressure gauge on the diaphragm.
Rose Calibration Company in Melbourne, Australia with over ten years of experience provides all calibration, maintenance, and repair services throughout Australia. If you live in Sydney, Melbourne, Adelaide, Perth, Geelong, and Brisbane, you can receive your quote in less than two hours by fill-up the form via the “Booking” link.