Digital sound level meter according to en 61672 1 class 2 with an unbeatable set of features in addition to standard features the sl 451 has a data logger and usb port with a robust housing and moulded protective rubber case this device is suitable for use in tough conditions the device has a measurement range from 30 to 130 db with auto range function the integrated data logger lets you store up to 32 000 measurements which can be transferred to your pc and processed using the software s