When trying to explain or state a number associated with how loud a sound or noise is it can be somewhat confusing or at the very least, ambiguous. This blog will help to make it clear and easy to understand the difference between Sound Power and Sound Pressure.
Sound Power is defined as the speed at which sound energy is radiated or transmitted for a given period of time. The SI unit of sound power is the watt. It is the power of the sound force on a surface of the medium of propagation of the sound wave.
Sound Pressure is the sound we hear and is defined as the atmospheric pressure disturbance that can vary by the conditions that the sound waves encounter such as furnishings in a room or if outdoors trees, buildings, etc. The unit of measurement for Sound Pressure is the decibel and its abbreviation is the dB.
I know, the difference is still clear as mud! Lets consider a simple analogy using a light bulb. A light bulb uses electricity to make light so the power required (stated in Watts) to light the bulb would be the “Sound Power” and the light generated or more specific the brightness is the “Sound Pressure”. Sound just as with the light emitting from the bulb diminishes as the distance increases from the source. Skipping the math to do this, it works out that the sound decreases by 6 dB as the distance from the sound source is doubled. A decrease of 3dB is half as loud (Sound Pressure) as the original source. As an example sound measured at 90 dB @ 36″ from the source would be 87dB at 54″ from the sound source or 84dB at 72″.
We at EXAIR specialize in making quiet and efficient point of use compressed air products, in fact most of our products either meet or exceed OSHA noise standards seen below.
EXAIR also offers the model 9104 Digital Sound Level Meter. It is an easy to use instrument for measuring and monitoring the sound level pressures in and around equipment and other manufacturing processes.
On any given day myself and my Application Engineering Brethren here at EXAIR have discussions with customers on air starvation of any given EXAIR Product. The calls generally start off the same, “The Line Vac is not performing like it should”. We at EXAIR absolutely want to help you get the most out of our products and we certainly want them to perform to your expectation. However they must be supplied with clean/dry compressed air at sufficient pressure and volume.
Just the other day I was discussing a performance issue with a customer on a 1″ Line Vac. The customer thought he needed a larger Line Vac. I asked the questions regarding the diameter of his Supply Line and if he was using Quick Connect or Push Lock connectors. He was attempting to feed this Line Vac with 1/4″ Poly Tubing through a elbow Push to Loc fitting.
This 1″ Line Vac was being severely starved for air and therefore not performing as expected. The 1″ Line Vac require’s 14.7 SCFM @ 80PSI to reach the rated performance of 42″ of water column.
Below is a table for Pipe/Hose sizing from the Line Vac installation manual that you can use as a reference guide. It is recommended that if using hose for the supply air to go up to the next size over the pipe recommendation.
Don’t forget that quick connects and Push Lock fittings are not recommended and could restrict the air flow which will have a negative impact on performance.
There are so many uses for compressed air in industry that it would be difficult to list every one of them as the list would be exhaustive. Some of the uses are the tools used in production lines, assembly & robotic cells, painting, chemical processing, hospitals, construction, woodworking and aerospace.
It is considered as important as water, electricity, petroleum based fuels and often referred to as the fourth utility in industry. The great advantage of compressed air is the high ratio of power to weight or power to volume. In comparison to an electric motor compressed air powered equipment is smoother. Also compressed air powered equipment generally requires less maintenance, is more reliable and economical than electric motor powered tools. In addition they are considered on the whole as safer than electric powered devices.
Even amusement parks have used compressed air in some capacity in the operation of thrill rides like roller coasters or to enhance the “wow factor” of certain attractions. Compressed air can be found in your dentist’s office where it is used to operate drills and other equipment. You will find compressed air in the tires on your car, motorcycle and bicycles. Essentially, if you think about it, compressed air is being used nearly everywhere.
Here at EXAIR, we manufacture Intelligent Compressed Air Products to help improve the efficiency in a wide variety of industrial operations. Whether you are looking to coat a surface with an atomized mist of liquid, conserve compressed air use and energy, cool an electrical enclosure, convey parts or bulk material from one location to another or clean a conveyor belt or web, chances are we have a product that will fit your specific need.
If you would like to discuss quiet, efficient compressed air products, I would enjoy hearing from you…give me a call.