WetView – ACS calibration (updated 11/15/2009)
Find:
Power supply
Wetlabs test cable (power, sixpin, serial)
Full carboy of DI water
2 pieces of hose with electrical tape (one with y, one long)
YSI meter
Plastic cup
Field laptop with woodgrain top panel
Notes:
As the DI water needs to be free of bubbles for a proper calibration, ensure that the carboy is filled well beforehand and sits for several hours.
Depending which wetlabs test cable is used, the power leads may be reversed.
WetView does not seem to consistently work through alternative ports (ie. usb/serial); COM1 is your best option.
Cleaning Procedure:
Remove one flow tube. Clean them one at a time so they don’t get mixed up.
Tube cleaning:
Rinse inside of tube with DI water, paying extra attention to ends where salt crystals can accumulate.
Wad a sheet of Kim-Wipe and stuff it into the tube. Soak the wipe with alcohol.
Push it through the tube with a length of something stiff enough to get it through the tube but soft enough not to scratch (a length of the stiffer tubing used on the flow-through system works well).
Repeat wipe operation with DI water.
Rinse inside of tube with DI water.
Inspect inside of tube – should be clean with no streaks or pieces of lint.
Window cleaning:
Rinse top and bottom windows with DI. Make sure to rinse away any salt crystals.
Moisten Kim-Wipe with alcohol. Wipe across window ONCE to remove any visible streaks – don’t scrub. Don’t reuse wipes – any dirt or salt picked up during the first wiping could scratch the window on subsequent wipings.
Repeat with new wipe if necessary.
Repeat with DI-moistened wipe.
Rinse with DI again.
Inspect.
Replace the flow tube, noting proper vertical orientation. Carefully slide the flow tubes into place without sliding dirt across the windows. Ensure the ends of the tube are fully seated on the instrument. Slide the sleeves up around the windows and over the O-rings, making certain they are firmly in place and aligned correctly. Hand tighten the allen bolt (note that the tubes are pressure-fit onto the instrument so the bolts help maintain plumbing orientation but do not need to be tightened very much).
Repeat with other flow tube.
Calibration Procedure:
Unplug pump from ACS. If you don’t do this, the pump will be damaged by running dry.
Plug laptop into ACS with test cable and serial port. Connect power cable.
Power on.
Open WetView from the desktop.
Open the correct device file by navigating to C:\IOP_profiler\cal and selecting the proper (most recent) ACS (014 or 037) or AC9 file.
Open C:\IOP_profiler\iop_cal.xls. Make sure you are on the worksheet that corresponds to the instrument being calibrated. (This spreadsheet keeps a running record of all ACS or AC9 in-house calibrations with the associated *.dat files and temperatures. The updated device/cal files from when the instruments go to wetlabs are also listed.)
Connect short, taped y-hose to outlets at top of tubes to ensure no stray light enters during calibration. Fill long hose with water and no bubbles. Connect to either a or c tube at the bottom, with taped portion at the tube rather than carboy. Make sure there is a short, taped hose with metal screen on the intake to the other tube. Begin water flowing into the cup with YSI probe in it for temperature determination. Use a medium-slow flow rate.
Once WetView is connected and talking to the ACS, click “up” “up” “in” “in” to recenter graph (these buttons are in the lower right corner of the WetView screen).
Hit F1 or the Start button in the upper left corner to begin recording data.
You should see a series of dots that fluctuate slightly as new data points are read. It should be +/-0.05 for most of the line for the tube currently being calibrated.
If a large offset is present, increase the water flow rate for a moment and then slow down again (trying blast bubbles out of the tube).
Record for ~30s, longer if bubble blasting was required.
Hit F2 or the Stop button in the upper left corner to stop recording data.
Save the file as q###tubedaterep (### = serial number of instrument; for example, q037c060308a.dat) in the C:\data\cruise\iop_profiler directory.
In iop_cal.xls, record the date, location of the calibration, cal file name, and temperatures from both WetView (instrument) and YSI (water). On the YSI meter, record the temperature that blinks occasionally, not the one that is shown consistently.
Repeat three times.
Switch tubes and repeat.
Copy the cal files to the proper cruise directory on porter. Copy the updated iop_cal.xls file to porter as well, saving it in two places: \\Porter.sr.unh.edu\shared\COOA and \\Porter.sr.unh.edu\shared\COOA\calfiles.
The *.dat files generated through this process are then used to create an offset file in Matlab (run ac_cal_analysis) that is required for processing data from the IOP Profiler.