Wet Labs ac-s, User Manual

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ac-s User’s Guide (ac-s) Revision F 9 Feb. 2006 3
1.3 Air Tracking
WET Labs provides an air calibration (.CAL) file similar to the device (.DEV) file and
can be applied in WETView in the same manner. The DEV file provides the clean water
offsets so that when measuring clean, fresh water, the instrument’s output should be very
nearly 0.0 for all channels. The .CAL file provides the offsets that provide 0.0 values
when the instrument is clean and dry and measuring air values. This is a useful tracking
tool for catching instrument drift, filter aging and improper cleaning.
When you install WETView, the latest air .CAL file should be transferred to your
WETVIEW directory. The name of the file takes the form AIRXXYYY.CAL where XX
is the calibration number; YYY is the instrument serial number.
When a .DEV file is opened in WETView, it will display *.DEV in the dialog box, which
will list all the .DEV files on the default drive. If you change the *.DEV to *.CAL, the
available .CAL files will be displayed. Select the latest .CAL file and start collecting
data. Make sure the black plastic caps are installed on the flow tube nozzles so no
ambient light can enter the flow tubes. If the instrument is clean and dry, the values
displayed in WETView should be very close to 0.0 (within 0.005–0.01). If the values are
within this range, the instrument is clean and ready to deploy. If the values are outside
this range, the first step is to re-clean the instrument and then reapply the .CAL file
offsets.
1.4 Cleaning
1. Remove flow tubes and all O-rings. Remove the sleeves from the flow tubes. Wash
the windows with a mild detergent diluted with distilled, reverse osmosis-filtered
(RO) or de-ionized (DI) water and rinse the flow tubes. Use Kimwipes or other lint-
free tissues to wash the windows. Rinse the meter off completely with water to ensure
no soap residue is left inside the flow tubes or on the windows.
2. Dry the meter. Place the instrument in a protected area where it can dry completely.
Using a small heater to blow warm air over the meter may help speed the process.
Using dry nitrogen to blow-dry the meter and remove water from the small grooves
around the windows will also help speed the process. It is suggested that the
instrument be left overnight to dry out completely. Reassemble the meter. Carefully
replace O-rings and slide collars back on to the flow tubes. Replace O-rings around
the windows.
3. Clean windows using a Kimwipe or lens paper. Place a couple of drops of methanol
or ethanol on the Kimwipe. With firm pressure, gently wipe the windows with
methanol. This should remove any visible streaks on the windows. If necessary,
follow with a dry wipe in one direction across the window face. Blow off any lint or
dust with a dry air source.
4. Clean the flow tubes by putting a few drops of methanol on a Kimwipe and, using a
wooden dowel rod, carefully slide the Kimwipe through the flow tube. Repeat this