Casella CEL Microdust Pro real time dust monitor - Manual (Page 23)

MicroDust Pro Aerosol Monitoring System
23 Casella CEL
Adjusting the zero and span settings
Figure 13. Adjusting the zero span settings
Refer to “ Calibrating the instrument for a specific type of particulate ” on page 25 for
instructions to calibrate the instrument for a specific type of particulate.
Zero adjustment
For sensitive measurements that will use the 0 to 2.5 mg/m³ or the
0 to 25 mg/m³ ranges, it is important to purge the probe with clean air before
making zero adjustments or measurements. Fine dust particles in the probe
assembly may never settle, even when the probe collar covers the inlet chamber.