Datalogging sound level meters are very useful instruments

Each field has its own instrumentation such as medical instruments for doctors and hospitals, tools and machinery for construction crews and even chalk, blackboards and whiteboards for the teaching profession. In the field of noise pollution and noise control the most important piece of equipment is the sound level meter.

 

Area sound level meters are used to measure the noise levels in the area and you will find that digital sound level meters are very popular. Datalogging sound level meters have proved to be very useful instruments in the field and are widely used in many industries. A sound level meter (SLM) is a device used to make frequency-weighted sound pressure level measurements displayed in dB-SPL. 0.0 dB-SPL is the threshold of hearing, and is equal to 20uPa (microPascals). This correlates to what one would aurally perceive when in a deep cave or in a large anechoic chamber.

Packaged as a single-function handheld test device, sound level meters are intended to be held at arm’s length during measurements (to reduce the effects of the body on the measurements) or secured to a tripod stand for more stability. The SPL range switch provides a balance between minimizing the preamp noise level and measuring a wide range of sound pressure levels. Most of the commonly available sound level meters measure from about 30 to 130 dB-SPL and do this in 3-4 ranges.

Almost all sound level meters are designed and specified to perform to one of four internationally standardized levels of accuracy:

·         Class-0 SLMs are employed primarily to calibrate other SLMs and may be used for very high precision noise measurement in controlled spaces and/or for academic research.

·         Class-1 and Class-2 SLMs are most widely used by acousticians, sound system professionals, industrial designers/ manufacturers and researchers in academia and government. Measurements made with these levels of accuracy are generally acceptable as evidence in the resolution of legal disputes.

·         Class-3 SLMs are restricted to noise survey meters and dosimeters.

Sound level meter - datalogging/ recording

Datalogging sound level meters record data over time either with a built-in memory or through a connection to a memory storage device such as the hard-drive of a PC or an external logger. As a small, battery-powered, and portable device which can be mounted on a tripod and left unattended and even located outdoors, datalogging sound level meters, equipped with internal memory, allow measurements to be recorded internally at user-defined intervals. 

After a measurement session is completed, the datalogging SLM can be brought to a PC to transfer the stored readings. This allows the user to store files, view graphs, and make hard-copy reports.

Most area sound level meters have the same set of user adjustments, including SPL range selection, A and C weighting filters, slow and fast detector response, and minimum or maximum SPL. Although digital sound level meters are not difficult to use, it is still necessary that the person operating the sound level meter has some training and knows how to use the equipment properly and to be able to understand the results.