Noise

We want to make it easy for you to become a sound pressure mathematical genius. Below you find sound pressure math explained in an easy-to-learn fashion that will make you an authority on sound pressure math. Imagine if someone had laid out tensor calculus for Einstein this way. He may have finished his theory of relativity years earlier. Now let us dive into the wonderful world of pascals, decibels, and other units and see how they relate to sound… More

Wallace Clement Sabine, born in 1868, is considered the father of architectural acoustics. He attended Ohio State University where he physics. He later went to Harvard to pursue his graduate studies. After graduating, he joined Harvard as a faculty member teaching physics. When it came to the study of sound, Sabine never had any formal training. He became fascinated with how sound differed from one lecture hall to another. Along with his assistants, he began moving materials to different lecture halls to see what materials made the lecture halls sound better. Sabine and his assistants spent many nights moving materials and measuring sound waves; he and his team used an organ and a stop watch to measure the deterioration of sound as it passed through the lecture hall… More

In order to determine the speed of sound in a particular medium, we need to know the medium’s elastic properties and its density. A medium’s elastic properties determine whether or not the medium will deform or lose its shape due to external forces. Sound travels faster in mediums with high elasticity and minimal deformity – like steel. Sound travels more slowly in less rigid mediums that deform easily – like rubber. Sound travels more slowly in mediums with greater density… More

In 1842 Christian Doppler hypothesized that sound frequencies change, relative to the observer, when emitted from a moving sound source. In 1845 Buys Ballot proved Doppler’s Hypothesis correct. As the ambulance approaches, the waves seem shorter and the frequency seems higher than when it moves away from you. When it’s moving away, the waves seem longer and the frequency seems lower… More

In 1970 Congress passed the Occupational Safety and Health Act. The act created The Occupational Safety and Health Administration (OSHA). It granted OSHA the authority to adopt existing federal standards or national consensus standards. In 1968 the American Conference of Government Industrial Hygienists published employee threshold limit values (TLVs) for hazardous substances. In 1971, per the act, OSHA adopted these standards calling them Employee Permissible Exposure Limits (PELs)… More

Traditional stay-in-place thermal insulation for piping and other components is rigid, and if it’s partially or fully removed for inspections or maintenance it usually can’t be replaced. Insulation that isn’t flexible, or rigid insulation, doesn’t work for every application. There are some cases where insulation blankets, like Thermaxx Jackets, are a better solution because they can be made with alternative insulation materials that are flexible. This allows for components of irregular shape to be insulated effectively. Read more.

Thermaxx Jackets has worked with many clients who are trying to make their food processing plant more energy efficient, safer, and cleaner (such as Calabro Cheese). The USDA recommends insulating pipes in food processing facilities, providing a layer of protection between the piping and your product. The insulation blankets used should be food grade or food safe. “Food grade” or “food safe” means that the insulation jacket designers consider the particular needs of the food processing plant. Read more…

Material manufacturers are required by law to publish Material Safety Data Specification (MSDS) sheets for their products. The MSDS sheet consists of the chemical and physical properties of a particular material like fiberglass or mineral wool. In addition to the MSDS, companies manufacturing materials that target the sound-reduction market often publish sound-reduction coefficients for their materials. The coefficients target individual frequencies. A problem arises when a company wants to offer a combination of materials. You just can’t add up the coefficients for the different materials. There is no formula you can use to determine the combination. The way to determine the coefficient is to test your combination of materials. In this article, we will take you through the testing process and show how the coefficients are calculated… More