The SL-4022 is an IEC 651, Type 1 digital sound level meter.

Features:

• Main function (frequency weighting & time weighting) and specifications are designed to meet IEC 651 type 1
• Large LCD display, easy to read
• A & C weighting networks are conformity to standards
• FAST & SLOW dynamic characteristic modes
• AC output for system expansion
• Built-in adjustable VR function: Easy 94dB calibration
• Condenser microphone for high accuracy & long-term stability
• Built-in max. hold reset switch
• Max. Hold function for stored the maximum value on display
• Warning indicator for over and under load
• LCD display for low power consumption & clear read-out even in bright ambient light condition
• Durable, long-lasting components, including a strong, light weight ABS-plastic housing case
• Compact and heavy duty housing case
• Low battery indicator
• Supplied with two 9V batteries, calibration screw driver, instruction manual, and hard carrying case