The Norsonic selection of sound calibrators comprises three types; Nor1251, Nor1252 and Nor1253.

The use of sound calibrators dates back to the days when it was easier to design a stable sound calibrator than a stable sound level meter. Today, sound measuring instruments, in general, are as stable as the sound calibrators.

However, measuring microphones are very delicate devices designed to fulfil very rigid specifications. This makes them vulnerable and subject to damage unless care is taken.

One may therefore say that a calibrator is just as much a verification of proper operation as it is a device for re-adjustment of sensitivity of sound measuring instruments.

The Norsonic selection of sound calibrators comprises three types, viz. the Nor1251, the Nor1252 and the Nor1253. The difference between them lies in their accuracy; while the Nor1251 is a class 1 calibrator and the Nor1252 is a class 2 calibrator, the Nor1253 is no less than a class L calibrator. It also satisfy all class 1 requirements!