TSI Instruments DustTrak 8520, Operation And Service Manual, Page: 43 / 89

Operation 33
2. Put the instrument in Log Mode 1.
3. Set the logging interval by pressing and holding the LOGGING
INTERVAL button down. The default choices for the logging intervals
can be reprogrammed using T
RAK
P
RO
software. One minute (i.e.,
“01:00”) is often a good choice.
4. Locate the D
UST
T
RAK
monitor and the reference sampler together so
that they are measuring from the same area.
5. Start sampling aerosol with both instruments at the same time.
Note: Greater accuracy will be obtained with longer samples. The
time you permit for sampling often depends on the reference
instrument and characteristics of the measured aerosol. It may
take some time to collect sufficient aerosol onto a filter cassette
for accurate gravimetric analysis. Refer to instructions of your
reference instrument for sampling times.
6. Stop sampling with both instruments at the same time.
7. Record the D
UST
T
RAK
monitor average concentration. Press the
STATISTICS key to view the average for the last test. If you wish to
determine a custom calibration factor for this test only, you can instead
receive the data into the T
RAK
P
RO
software.
8. Determine the mass concentration in mg/m
3
from your reference
instrument. For gravimetric sampling this means having the gravimetric
sample weighed.
9. Compute the new calibration constant, NewCal, using the following
formula:
CurrentCal
ion Concentrat DustTrak
ion Concentrat Reference
NewCal
⋅






=
The calibration factor, OldCal, can be obtained from the D
UST
T
RAK
monitor. In Survey mode, press and hold the CALIBRATE key down
until the display counts down to zero. Release immediately when zero is
reached and “CALIBRATE ZERO” appears on the display. If not, try
again until it does. Press CALIBRATE again and the current calibration
factor will be displayed with flashing up and down arrows. Record this
value to make your calculation. Press CALIBRATE again to exit
calibration mode.
Setting Custom Calibration Factor from Keypad
1. In Survey mode, press and hold the CALIBRATE key down until the
D
UST
T
RAK
monitor counts down to zero. Release the button