Dust Detective
10
Starting measurements
Checking the Instrument’s Zero
Check the zero calibration for the Microdust Pro before every use. This can be achieved either as described on
Page 28 of the
Microdust Pro
Handbook
, utilising the purge air bellows connected to the probe purge point.
Alternatively, to zero in situ, remove the inlet cowl, and connect the clean air filter to the inlet tube, start the
Apex2 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 Page 31 of the
Microdust Pro Handbook
.
The span can also be checked by inserting the calibration filter and checking the reading. If required, adjust
the span control according to the handbook.
Sampling Pump
The Dust Detective enclosure is designed to use the Apex2 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 5 L/min whilst using a 37 mm GFA filter. Automatic flow
control circuitry is used to maintain a stable sample flow rate over varying pressure drop conditions. PUF
filters are designed to operate at a flow rate of up to 3.5 L/min, refer to the
Apex 2 Handbook
(page 13) for
details on changing the flow rate.
To switch the pump on, press the power key on the pump. To start the pump running press the Enter Key.
When running, flow rate will appear on the display and a blue flashing light will be visible at the top of the
pump. To stop the pump, hold the Enter key again.
To switch the pump off, press and hold the Power key and the pump will countdown to off.
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.
Install the sample inlet tube/head to the case (see Figure 1).
2.
Insert the PUF filter foam(s) and in line sample filter (if required) (see Figure 4 & 5).
3.
Switch the Microdust and Apex2 on. Confirm the Zero and Span settings are correct as described
above.
4.
Set the Apex2 flow rate to 2L/min
5.
With the unit located for measurement, start the Microdust logging by holding the Play key and start
the pump by holding down the Enter key.
6.
Shut and lock the Dust Detective Case.
