Casella CEL-620 [CEL-620.C1] Third Octave Band Sound Analyzer Type 1 w/Standard Accessories. Casella CEL-620 Casella Integrating Third Octave Band Sound Level Meter (Class 1). Casella's CEL-620 series of sound analyzers feature powerful dsp processing and a wide measurement range. With the capability to monitor using a single range of 20 to 140 dB, measurements are greatly simplified with no need to change ranges during measurement or predetermine the correct range. Every 620 series sound analyzer features a large color display and is capable of storing up to 100 runs for later review or download to a PC. The CEL-630 series of sound analyzers are also available and can be ordered with additional logging capabilities. In addition to providing all the capabilities of a standard sound level meter, the CEL-620 series powerful DSP processor stores all sound data simultaneoulsy every run. There are two models and three options available. The difference between the CEL-620 and CEL-621 is that the CEL-621 provides statistical parameters used for environmental measurements. Each model is available in three versions including the standard 'A' model which monitors all frequency and time weightings simultaneously, the 'B' model which adds 11 simultaneous octave bands, and the 'C' model which adds 33 simultaneous third octave bands. CEL-620 and CEL-621 sound analyzers are available with microphones for type 1 or type 2 ANSI accuracy. The CEL-620 can be upgraded to a CEL-621 and/or octave bands added at a later date.

High Resolution Colour Display.
The 620 series uses colours on the high-resolution display to aid the user in making measurements. Measurement screens are colour coded depending on the mode of operation, for example, during a measurement run, the header and footer of the display is green (shown right), whereas when a run is stopped they are red, similar to traffic lights for ‘stop’ and ‘go’. Measured parameters are displayed in different colours, and the bar graphs are illustrated with the same colours to give an easy understanding of the noise climate.