Casella CEL Microdust Pro real time dust monitor - Manual (Page 39)

MicroDust Pro Aerosol Monitoring System
39 Casella CEL
The cyclone (10) is fitted to the adapter block (2) using an O-ring seal. A
suitable constant-flow pump such as the Casella TUFF or Apex should be
connected to the filter cassette (12) through a length of silicone tubing.
It is important that the cyclone must operate in the vertical orientation. You
should also clean the coarse dust container (11) and check it for damage at
regular intervals.
When you install a new filter in the filter cassette, make sure it is held firmly
against the filter support pad. If the filter is loose, the instrument will give
incorrect measurements.
When the cyclone is pressed into the adapter block, make sure the cyclone’s
locating spigot (9) engages the probe inlet so that the adapter assembly cannot
rotate or slide on the sampling probe. Use the thumb screw to secure the
adapter assembly in position.
PUF filter adapter
The MicroDust polyurethane foam filter (PUF filter) adapter is for use in PM
10
,
respirable and PM
2.5
sampling applications that have a flow rate of
3.5 litres/minute. The design is based on the Conical Inhalable Sampler (CIS),
which is identified in the Health and Safety Executive’s publication MDHS14.
For monitoring applications, the adapter is fitted to the sampling probe as
shown in
Figure 21 .
The air sample is drawn through the PUF filter and then into the MicroDust Pro
measuring chamber before being deposited onto the filter (25 mm or 37 mm).
The type of foam filter loaded into the adapter determines the size of particulate
matter being monitored by the MicroDust Pro and being collected on the filter.
The PUF filter inserts have been designed as size-selective filters to capture
particles that are larger than a specified mean aerodynamic size. However, it is
also possible to pre-weigh and post-weigh the PUF inserts to determine the
total inhalable size dust fraction value and the desired size fraction.
PUF filters should be stored in a clean and, preferably, air-conditioned
environment.
If used without PUF filters the CIS adaptor will provide the total inhalable size
dust fraction into the MicroDust for real-time measurement.