HomeTechnologyWhat We Measure: Particulate Matter (PM2.5)

What We Measure: Particulate Matter (PM2.5)

Have you ever noticed yellow haze or bushfire haze? Dirty, smoky air is caused by particulate matter. Plenty of evidence shows that particulate pollution, especially the smallest particles, can increase the risk of heart disease, lung cancer and asthma, and interfere with lung growth and function.

What is PM2.5?

Particles refer to mixtures of solid particles and liquid droplets in the air. Some particles such as dust or dirt are visible to the naked eye. Other particles are so small that an electron microscope is needed to see them.

PM2.5 is respirable fine particles less than 2.5 micrometers in diameter (human hair is 30 times larger!) These particles – from exhaust fumes, industrial processes and smoke – enter through HVAC, doors and windows and “leaks” into buildings and constructions. who come in. Particles can also come from indoor sources such as pollen, mold spores. and cleaning products

Why measure PM2.5?

Its small size allows measure PM2.5 to bypass many of the body’s barriers. Unlike large dust particles, PM2.5 can penetrate the fibrous tissue and travel to the blood and lungs. Short-term exposure has been associated with throat irritation, coughing and difficulty breathing. More serious long-term health effects can include respiratory problems, heart disease, and cancer.

While PM2.5 is particularly dangerous for people with heart and lung disease, the elderly and children, it has been shown to affect healthy people as well.

Consequences of forest fires

Although PM2.5 has decreased in the United States in recent decades. Areas, where wildfires are likely to increase significantly Breathing high concentrations of PM2.5, can increase the risk of asthma, heart attacks and strokes.

Let your building be strong

Use Awair air quality data to monitor PM2.5 and to develop indoor air quality removal sequences and policies for high PM2.5 events.

Propellers must be the correct diameter to fit boats. When the mast does not help the ship to achieve maximum performance. A simple increase or decrease in diameter solves the problem and increases efficiency. The correct diameter depends on the length of the boat. Half the weight of the vessel when loaded, as well as the maximum allowable engine speed and the movement of the water diameter caused by planing or boat movements are also useful in determining disk space and disk space ratio.

The ideal propeller diameter is usually stamped on the side of the wheel hub closest to the propeller shaft hole. There will be two figures. The first number is the diameter of the pole. For example, if the given number is 12×11, the diameter in this case is -12 as the first number.

The correct way to measure the diameter of the pole is to use a tape measure. The distance between the blade edge and the centerline of the shaft hole should be measured to give the radius by two multiplications of the diameter of the pile. The common view is that the larger the diameter, the better the performance. This is not always the case. Under the hood, restrictions can be placed on the view of the ship based on the diameter of the mast.

Another way to measure the overall diameter is to measure the circle around the propeller point to point. Installing larger diameter propellers on the boat will increase the torque to make it spin at the specified speed. The wheel has a diameter, usually in one inch increments. Therefore, all measurements must be made in inches.

Hub diameter is another diameter that affects propeller size and performance. The diameter of the wheel coupling is measured by doubling the blade length of the wheel from the base of the blade to the tip.

Boat use is an important consideration when increasing or decreasing the diameter of the mast. A ship that carries or carries heavy loads. Or for casual cruises, larger diameter struts are needed. Cruise ships, pontoons and some fishing boats are examples of boats that require larger diameter struts. Larger diameter propellers provide more thrust for slower boats. Speedboats for racing or other recreational activities. Smaller diameter sticks are more efficient. For slow or still water in lakes and rivers, large diameter struts will perform well. For multiple bays, smaller diameter struts work better.


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