Sound Level Meters are divided into two “classes”. Both have the same functionality but different tolerances for error. Class 1 instruments have a wider frequency range and a tighter tolerance than a lower cost, Class 2 meter.
As a manufacturer, we abide by certain standards such as IEC 61672-1. The standards define the performance criteria to be met by our noise measurement instruments including levels of tolerance. If you are interested in finding out more about standards relevant to sound level meters, read Part 2 and Part 3 of IEC 61672.