A Comprehensive Guide to Manometers in New Zealand

Manometers come in a variety of different types, each suited to different applications and pressure standards. The most common types of manometers include U-Tube Manometers, Micromanometers, Inclined Manometers, Digital Manometers, Gas Manometers, and Water Manometers. We will explore a few of these types in further detail below.  

U-Tube Manometers

U-tube manometers are one of the simplest varieties available. They are a type of analogue manometer commonly used as differential pressure measurement instruments with flow meters, often used when measuring pressure difference in pitot tubes, nozzles and orifices in airflow and ventilation systems. 

U-tube manometers consist of relatively few parts and are usually one of the cheaper types of manometer, but the trade-off for this is that accuracy can be poor. As a result, a u-tube manometer should not be used to measure particularly small pressure differences and an alternative manometer should be used instead. Lastly, the viewing angle is key when working with u-tube manometers to ensure the reading is as accurate as possible. 

Inclined Manometers

Inclined manometers are typically used to measure liquids and gases where the pressure is very low. The angled design of the inclined manometer makes it particularly well-suited to this role, enabling accurate measurements to be taken. Despite this, digital manometers are often preferred nowadays due to their high levels of accuracy and ease of use. 

Digital Manometers 

Digital manometers have largely become the norm and are now widely used by professionals for a variety of measurement applications. As opposed to analogue manometers, digital models contain a pressure transducer which deflects under pressure. The device then converts the deflection into the value of an electrical parameter which can be detected and calibrated to a pressure reading, in turn, thus providing the measurement. 

Precise and easy to read, digital manometers can be used for multiple mediums and can also be calibrated to ensure a greater degree of accuracy. Gauge and absolute digital manometers will have a single connection port – gauge reading is relative to atmospheric pressure and absolute reading is relative to a vacuum. It’s also worth noting that some models allow for communication between the manometer and a PC to enable quick and easy download of either stored or live measurements and recordings. 

Digital manometers are advantageous for a number of reasons, including: 

• Portability
• Easy to read and use
• Avoid reliance on manometric fluids
• High degree of accuracy and precision

Gas Manometers

Gas manometers, as the name suggests, are specifically designed for measuring the pressure of gases. They are commonly used by heating and boiler engineers for tasks such as monitoring gas pressure in piping systems. Gas manometers are typically available in both digital and analogue versions, and they are often used in conjunction with other tools and instruments to ensure the safe and efficient operation of gas-related systems.

Water Manometers

Water manometers are used to measure the pressure of liquids, with water being the most common medium. Water manometers are often used in applications where the pressure to be measured is relatively low, and they are commonly used in tasks such as calibrating other pressure instruments or ensuring the proper functioning of liquid-based systems.  

Manometers are versatile instruments and are used in many different industries and applications. Below, we will explore a few of the most common use cases for manometers, including the use of manometers for gas pressure, water pressure, and air pressure.  

Manometers for Gas Pressure

Gas manometers are used by heating and boiler engineers for a variety of purposes including monitoring gas pressure in piping systems. It is important to ensure a manometer used for gas pressure is ATEX approved as this certification ensures the instrument is suitable for use in potentially hazardous environments. 

Manometers for Water Pressure

When using a manometer to measure water pressure, the model in use must be suitable for liquids to avoid potential damage to the instrument. Similarly, if the liquid contains chemicals or other potentially hazardous substances, you should be aware of the damage it could cause if an unsuitable manometer is used. Additionally, over-pressuring the manometer may cause subsequent readings to be incorrect due to internal diaphragm bending or rupturing, so it is essential to use the correct instrument with care. 

Manometers for Air Pressure

Digital air pressure manometers are used in many process industries. They can also be used with pitot tubes or venturi to determine air flow rate in a pipe. Before use, it is important to check the temperature of the air and note the maximum medium temperature in the operating manual for the particular model of manometer. 

Ultimately, the best manometer will largely depend on its intended use and any specific requirements of the task at hand. It is always recommended to do thorough research before deciding on a manometer as it is important to ensure the instrument is well-suited to the job it will be performing. 

To compare manometers as a general rule, u-tube manometers tend to be cheaper and less complex, although they are also less accurate than other alternative types. Compare digital vs analogue manometers and you will find that digital models are better for measuring smaller differences as analogue instruments can be affected by the angle of viewing. Analogue manometers are better for rapidly fluctuating signals, yet on the flip side, it can be difficult to integrate analogue manometers into IIoT (Industrial Internet of Things) systems. 

With so many different types of manometer available, it is important to select the right instrument for your requirements. There are several important factors you should keep in mind when choosing a manometer.  

Key considerations include: 

• Maximum pressure required
• Resolution
• Differential, gauge or absolute
• Brand