TSI Instruments DustTrak 8520, Operation And Service Manual

Page: 75 / 89

Operation 65
If desired, the D
UST
T
RAK
RJ45 cable may be attached directly to the inside
of the DB9 connector located on the side of the Environmental Enclosure. A
serial cable (not supplied) may then be attached from the outside of the DB9
connector to the computer COM port.
Note: In order to download a data file the D
UST
T
RAK
monitor cannot be
in a sampling mode.
The primary use for the external DB9 connector is to facilitate real-time data
monitoring. An external computer or data logger can be directly attached to
the D
UST
T
RAK
monitor, while still keeping the instrument inside its
weatherproof enclosure. The D
UST
T
RAK
monitor can be queried through a
set of ASCII commands to provide periodic information.
Zeroing the D
UST
T
RAK
Aerosol Monitor
The D
UST
T
RAK
monitor should always be zeroed before beginning a
sample. See the instructions in Chapter 3 of this manual for more
information. If possible, the instrument should be zeroed under stable
ambient temperature conditions (since variations in temperature will have a
small impact upon the D
UST
T
RAK
monitor readings). If this is not possible
(for example, 24-hour outdoor sampling, with wide temperature swings) the
instrument should be kept closed inside the Environmental Enclosure. The
thermal mass of the Enclosure will dampen out the affect of temperature
swings, radiant heat, etc.
Note: See the D
UST
T
RAK
monitor Specifications in Appendix A for more
information on the temperature dependence.
In nearly all cases, the temperature impact upon the D
UST
T
RAK
monitor
reading is very small in comparison to the ambient particle concentration.
Setting the Flow Rate
The aerosol inlet on the Environmental Enclosure was designed to operate at
a 1.7 liters/minute flow rate. Before each sample, the flow rate should be
verified and/or adjusted as described in the D
UST
T
RAK
monitor Maintenance
section ( Chapter 4 ).
Locking the Environmental Enclosure
To avoid theft of the D
UST
T
RAK
monitor
,
when left inside the Environmental
Enclosure, a padlock should be used to lock the box. There are two holes on
the front of the box that allow for a standard padlock to be attached. A
padlock is
not supplied with the 8520-1.