Manometers

Manometers, also known as pressure meters, measure the pressure of gases or liquids. Many modern models are handheld and digital, with clear displays and features such as backlighting, data logging and wireless connectivity. A digital manometer uses an internal sensor to convert pressure into an electrical reading. Depending on the model, it may measure gauge, absolute or differential pressure across different ranges and units.

RS Hong Kong stocks manometers from brands including Druck, Digitron, Testo and RS PRO. We also offer in-house calibration services for your manometer if required.

Types of Manometers

Manometers can be grouped in two ways: by the pressure reference they measure against, and by their construction.

Before choosing one, consider:

• Pressure type: Gauge, absolute or differential
• Measurement range: The minimum and maximum pressure the instrument can handle
• Accuracy: The level of precision required for the job
• Number of ports: One port for many gauge or absolute readings, or two for differential pressure
• Additional features: Data logging, backlighting, wireless connectivity or minimum and maximum recording
• Working environment: IP rating and suitability for hazardous areas

Differential Pressure Manometers

A differential pressure manometer measures the difference in pressure between two set points, using two ports connected to either side of a system. This makes a differential pressure meter ideal for pressure-drop and leak testing across filters, valves, and gas pipes, and for airflow work with pitot tubes.

Absolute Pressure Manometers

An absolute pressure manometer measures pressure against a perfect vacuum rather than the surrounding atmosphere. Because the reference does not change with local weather or altitude, absolute manometers are useful when the measurement must remain independent of changes in ambient pressure. Applications may include laboratory work, process measurement, vacuum systems and barometric readings.

Gauge Pressure Manometers

A gauge pressure manometer measures pressure in relation to the surrounding atmospheric pressure. This is the type of reading commonly used when checking how far the pressure inside a system sits above or below ambient conditions. Gauge manometers are suitable for routine servicing, equipment checks and general troubleshooting across pneumatic, hydraulic and industrial systems. A familiar example is tyre pressure, which is normally shown as pressure above the surrounding atmosphere.

Vacuum Manometers

Vacuum manometers measure pressure below the surrounding atmospheric pressure. Depending on the instrument, the result may be shown as negative gauge pressure or as an absolute pressure value. Suitable vacuum instruments are used during the installation and servicing of refrigeration, air-conditioning and vacuum systems. During refrigeration work, technicians use vacuum measurement to monitor evacuation and help remove moisture and unwanted gases before the system is charged. The required vacuum range and instrument type depend on the application, so a general-purpose pressure meter may not be suitable for deep-vacuum work.

Digital & Analogue Manometers

Manometers are also split by construction. Analogue types, such as U-tube and inclined manometers, read pressure from a column of liquid and are simple and low-cost, though the viewing angle affects accuracy. A digital manometer instead uses a pressure transducer that deflects under pressure and converts that movement into a precise electrical reading, offering better accuracy, easier reading, and the ability to log or download data. Digital models now dominate professional use and make up the bulk of the RS Hong Kong range.

Applications of Manometers

Manometers are used to measure, compare and monitor pressure across HVAC systems, gas installations, industrial equipment and ventilation networks.

HVAC & Refrigeration Systems

HVAC technicians use differential manometers to measure pressure drops across filters, fans and ductwork. These readings help identify restricted airflow and support system balancing and commissioning. Refrigeration work may require digital manifolds and vacuum gauges that measure pressure alongside temperature. Together, these readings help technicians assess superheating, subcooling, evacuation and system tightness.

Gas Pipeline & Leak Testing

Manometers can be used to monitor pressure during gas-pipe testing. Once a line has been pressurised according to the required procedure, technicians watch for changes over a set period. An unexpected pressure drop may indicate a leak, although temperature changes and other test conditions must also be considered. Testing should always be carried out with an instrument suited to the gas, pressure range and working environment.

Industrial Process Monitoring

Maintenance teams use handheld manometers to check pressure across equipment, pipelines and process systems. Taking a reading on site helps technicians compare current performance with the expected operating range, investigate pressure-related faults and identify where further inspection may be needed. Data-logging models can also record readings for later review.

Airflow & Ventilation Testing

Differential manometers measure pressure across ducts, vents, fans and filters to help assess ventilation performance. When paired with a compatible Pitot tube, selected instruments can use the pressure difference to calculate air velocity and volume flow. These measurements help technicians balance ventilation systems and check whether airflow meets the required design values.

Buy Manometers from RS Hong Kong

As a trusted manometer supplier, RS Hong Kong stocks a comprehensive range of manometers and digital pressure meters from brands including Druck, Comark, Testo, and our own RS PRO brand. From a compact handheld manometer for fieldwork to differential and intrinsically safe models for hazardous areas, you will find the right instrument across a wide choice of pressure ranges, IP ratings, and price points. Compare manometer prices and specifications online before choosing a digital model suited to your application. You can also add pressure calibrators and pressure gauges to complete your test kit. For full details on delivery services and fees, please refer to our Delivery page.