SLT is a class II (type 2) sound level, sound pressure level (SPL), decibel (dB) or noise meter with audible or visual alarm output capability. SLT is used for long-term, continuous monitoring of occupational noise exposure limits in industrial environments such as foundries, factories and manufacturing production floors. The measuring device consists of a wall-mountable acoustic sensor on a 1.5 m / 4.92' long cable and a transmitter.