Manual, Ultra High Sensitivity Aerosol Spectrometer (UHSAS)
DOC-0210 Rev E-4
3 9
© 2017 DROPLET MEASUREMENT TECHNOLOGIES
8)
Replace the port, lift the rear interlock, and observe the laser power for one minute
by examining if
Reference
has returned approximately to 2.5 V. If the power is still
low, press the rear interlock (the laser interlock) down to OFF and repeat steps 7-8 of
the procedure. It generally will take numerous attempts to return the laser to normal
power.
9)
Reinstall cleaning port and replace the lock-down screws.
10)
If laser reference power is still low, repeat the cleaning procedure outlined in steps 7-
10 for the optic at the back end of the optical block. This is the crystal/laser end.
Use
caution
, as the crystal end is delicate and scratches easily. Only clean the crystal end
when necessary and with the laser OFF.
11)
Close the tubing on the optical block exhaust line.
12)
Reinstall cover on the unit. Do not install screws into cover until power has been
rechecked in case the unit requires more cleaning.
13)
Turn on the laser current and run the instrument normally for 15 minutes to stabilize.
14)
Check the
Reference
and
Scatter
levels of the unit. The cleaning was successful if
these values are within 15% of desired values (2.5 V for
Reference,
factory-calibrated
value for
Scatter
.) If they are lower than when the cleaning started, the cleaning was
unsuccessful.
15)
Repeat above steps until adequate
Scatter
and
Reference
levels have been attained.
16)
Install the 16 Phillips-head mounting screws into the cover. The unit is ready for use.
In the unlikely event that cleaning does not adequately raise the laser power, consult a DMT
service representative for further assistance. If the instrument becomes contaminated, it should
be returned to the manufacturer for decontamination, cleaning, and service.
8.0
Communications
A serial port for data transmission to an external data system is available through the back
panel. This data stream is ascii text at 115,200 baud, 8N1, tab-delimited.
NOTE:
The serial-
stream data are transmitted at the same repetition rate as the
Sample Time
specified on the
Histogram
tab; if this sample time is set to five minutes, the serial packet will only be sent out
once every five minutes. The header of the serial stream is a channel list in the same format as
the first 2 lines of the data file, and it is sent before any data are transmitted. The serial port
connector is a standard 9-pin D-connector and can be connected to the serial port of an external
computer with a standard female/male straight serial cable. The serial port is determined by the
Broadcast Port COM
parameter on the
Configuration
tab. If this port is set to 0, no data are
broadcast.
See your IT support department for assistance with connecting the UHSAS to the local network
or internet.
