Casella CEL Dust Detective kit case for Microdust Pro - Manual (Page 6)

6
Powering up and using the system
Checking the Instrument’s Zero
Check the zero calibration for the Microdust Pro before every use. This can be achieved either as
described in the Microdust Pro handbook, utilising the purge air bellows connected to the probe
purge points. Alternatively to calibrate in situ, remove the inlet cowl, and connect the in-line air
filter to the inlet tube, start the Apex pump. With clean air in the probe, the display should be
zeroed.
Checking Probe Span
The span of the Microdust pro should be checked in accordance with the relevant User Manual.
The span can also be checked by inserting the calibration filter and checking the reading. If
required, adjust the span control according to the User Manual.
Sampling Pump
The Dust Detective enclosure is designed to use the Apex range of personal samplers. This
allows the user to take a standard personal sampling pump, charge the unit up and install inside
the enclosure. The pumps are designed to provide a flow rate capability of up to 4.0 L/min whilst
using a 37 mm GFA filter head (at up to 25 cm H
2
0 pressure drop). Automatic flow control
circuitry is used to maintain a stable sample flow rate over varying pressure drop conditions.
To switch the pump on, press the enter key on the pump. When running a real time flow meter
symbol will appear on the display and a green flashing light will be visible at the top of the pump.
To switch the pump off, press and hold the enter key and the pump will countdown to off.
PUF filters are designed to operate at a flow rate of 3.5 L/min.
Check the performance and calibrate the Apex sampling pump according to the manual and
adjust the flow rate to 3.5 L/min.
If the pump is unable to maintain the selected flow rate due to excessive pressure drop or an inlet
blockage, the red LED will begin to flash and the warning tone will bleep rapidly.
Starting a Sample Run
1. Remove the protective dust cap and fit the sample inlet tube/head to the case (see
fig 2).
2. Insert the PUF filter foam(s) and in line sample filter (if required) (see figure 3,4).
3. Switch the Microdust pro and Apex pump on. Confirm zero using the in-line filter
connected to the sample inlet.
4. Check that the Apex flow rate is set to 3.5L/min.
5. Locate unit in required location. Start pump and Microdust data logger according to
their respective user manuals.