What is a Differential Pressure Manometer?Metravi Instruments
Pressure is a crucial parameter, once which plays a huge role in a lot of industrial and engineering processes. A modern Differential Pressure Manometer helps measure differential pressure – the difference in pressure between two pressure readings; a measure which helps to indicate if any industrial processes are running incorrectly or that immediate system adjustments are required. The same can also indicate problems in HVAC systems, pipes, pumping, mass/volume flow processes, etc.
Differential pressure between two parts of a system is not always an indicator of something wrong. These manometers help technicians and operators to assess the functionality status of industrial and HVAC equipment and systems.
For example, a technician can measure the pressure on two sides of an air filter and use the differential measurement to determine if the filter is operating within the expected and acceptable parameters.
Manometers can be broken into two broad categories: differential pressure and single-pressure.
- Differential pressure manometers take two or more measurements and measure the difference between the two readings. These can read positive pressure or even a vacuum on either side of the equation. Technicians use differential readings for regular assessments, inspections and repairs.
- Single pressure manometers only measure one pressure source and compare it to the open atmosphere. The comparison between a single pressure source and the atmosphere is also called gauge pressure.
Differential Pressure Manometer applications include but are not limited to:
- Static Pressure Measurement monitoring in duct or plenum.
- Adjusting efficient combustion.
- Measuring gas pressure for heating burner.
- Adjusting pressure drop in dust scrubber.
- Gauging damper position in duct.
- Sensing loss of lubricating oil to saw bled.
- Measuring / monitoring negative pressure during asbestos removal operation.
- Measuring change in air pressure in textile equipment.
- Measuring pressurisation of rooms.
- Measuring air velocity in duct.
- Measuring air velocity in Orifice Plate.
- Measuring differential pressure across fan.
- Indicating filter condition in any close process.
- Monitoring draft in smoke, stack.
- Monitoring air flow in oven.
- Measuring wind speed in duct or process.
- Measuring test pressure in air flow.
- Measuring air velocity round the clock.
- Measuring low flow of stack gas.
- Accurate measurement of stack gas velocity.
- Showing pressure and accurate during kidney dialysis.
- Use in gasoline vapour recovery system.
- Measuring tank level of liquid.
- Controlling yarn size from carding machine.
- Measuring level of liquid nitrogen in tank.
- Measuring drop across Orifice Plate.
- Indicating condition of filter in liquid pipe line.
- Measuring water florid.
- Use as Orifice Meter on liquid pipe line.
- Use in system to measure integrity of auto fuel system.
- Leak testing in containers or assembly.
- Monitoring filter loading.
- Use in cleaning cycle for bag house cleaning.
Differential Pressure Manometer Application for HVAC
In HVAC ducting, condenser coils cool air flowing through an air conditioner. Consequently, over time, dirt accumulates on the coils, which restricts air flow and reduces heat transfer. These factors in combination decrease the efficiency of the coils. Hence, as dirt accumulates, the resistance to the flow and the differential pressure across the coils also increases.
A handheld digital differential pressure manometer is an excellent means of measuring the change in pressure across the coils. Its compact design allows for easy portability from job to job, the digital display is easy to read, and the accuracy meets the requirements for this type of testing.
In high rise buildings, since energy costs are high, it is important that chillers (refrigeration machines) be maintained at maximum efficiency. Cooling costs can increase 50% due to scaling in the condenser tubes. Scale build-up inhibits water flow and as the scale builds up inside the condenser, the differential between upstream and downstream pressure increases. Thus, again, a manometer can be used to monitor the change.
The Metravi PM-01 Digital Differential Pressure Manometer measures gauge and differential pressure up to ±0.500 psi. Offering 11 selectable units of measure, it can serve as a low range/high resolution Gauge or provide Differential Pressure up to 0 to 138.3 in. H2O (inches of water).
Max/Min recording and Relative time stamp are available along with Data Hold and Auto Power Off features. Zero function is available for offset correction or measurement and a built-in USB interface. The device kit comes complete with 9V battery, software, USB cable, AC Adaptor, connection hose, built-in stand, and the Operating Manual in a hard carrying case.
The Metravi ET-99P is a pocket-sized, compact, Differential Pressure Manometer and measures Gauge/Differential Pressure from -5000Pa to +5000Pa.
It features 11 selectable units of measure: Pa, hPa, mbar, mmH20, mmHg, inH20, inHg, psi, ozin2, bar, kPa.
Additional features include Data Hold, Auto Power-off with disabling function.