Manometer
A manometer is a scientific device that is used to pressure differences, this could be pressure relative to atmospheric pressure (a barometer), within a vessel or chamber, a gas or liquid to calculate flow rates through a device such as a duct or blood pressure in a person.
They are commonly used in the construction industry for building services to measure system air pressure in heating, ventilation, and air conditioning systems, airflows, positive and negative pressures in ducts, or pressure differentials across filters and coils. There are effectively four types of manometers, the first two relying on a fluid, in a closed or open tube, and the third, aneroid manometer, without a fluid and finally a digital aneroid manometer, they all measure pressure through comparison or differentials.
A barometer is a common closed tube type of manometer, the closed tube contains mercury, and it is used to measure in comparison to atmospheric pressure. These are familiar devices often found outside windows in homes, to measure the outside air pressure to assist in weather predictions, rising air pressure indicates a good weather forecast whilst falling pressure might forecast rain or bad weather. Another common type of manometer is a sphygmomanometer used to measure and monitor blood pressure, these are either mercury and aneroid types. Manometers are also a component part of balometers, airflow meters or air flow hoods, used to measure the flow rate of air leaving or entering the ventilation outlet of an airflow system.
There are a number of different open tube analogue types of manometers, which include U-tube, enlarged-leg, well-type and inclined-tube manometer each with a specific design varying approach and accuracy. They all essentially measure pressure exerted by the atmosphere at one end of the tube or one part of the design and compare this with a known pressure at the other or other part, to give the pressure. Aneroid manometers indicate by air pressure via an inflation device (such as a diaphragm or Bourdon tube).
The final type of manometer is a modern digital device, it does not use a fluid, but a pressure transducer. An elastic portion of the transducer detects pressure levels and converts this energy into an electronic signal, producing a number instantaneously on a digital display. Manometers essentially measure pressure difference by applying the fluid column principle in analogue devices and transducers in digital devices, this differs from pressure gauges which more specifically measure or check a single pressure, rather than by comparison.
[edit] Related articles on Designing Buildings
- Air change rates
- Air conditioning.
- Air infiltration.
- Air permeability testing.
- Air quality.
- Air tightness in buildings.
- Changes to Building Regulations Part F.
- Computational fluid dynamics.
- Condensation.
- Cross ventilation.
- Cultivating Cleaner Air with BSRIA.
- Displacement ventilation.
- Domestic ventilation systems performance
- Draughts in buildings.
- Effective ventilation in buildings.
- Heat recovery ventilation.
- Indoor air quality.
- Mechanical ventilation.
- Natural ventilation.
- Passive building design.
- Stale air.
- UV disinfection of building air to remove harmful bacteria and viruses.
- Ventilation.
Featured articles and news
Top 50 firms awarded 52bn of projects in the last year
New engineering data shows.
Enhancing construction site reporting efficiency
Through digitisation and the digital revolution.
Noise in the built environment
BSRIA guide TG 20/2021.
17,000 people suffer conditions as a result of exposure to excessive noise at work.
Turning down the noise: Auditory health
A pervasive risk with far-reaching consequences.
UK Construction Week, London is here !
Debuting major international pavilions and much more.
Getting the most out of heat pumps and heating
How heat pumps work and how they work best.
Plumbing and heating for successful retrofit and renovation
Low temperature underfloor systems and heat pumps.
Cost-of-living crisis and home improvement plans
Starting on the right footing and top tips for projects.
Delays on construction projects
Types, mitigation and the acceleration of works.
From Chaucer to Fawlty Towers.
Electrotechnical excellence, now open for entries.
Net zero electricity grids BSRIA guide NZG 5/2024
Outlining the changes needed to transition to net zero.
CIOB Global Student Challenge 2024
Universitas Indonesia wins for second year running.
ECA 2024 Apprentice of the Year Award
Entries open for submission until May 31.