LBNL pgII user guide

PabOpto pgII Users guide for LBL users


This page describes typical operation of the LBL PabOpto pgII photogoniometer.

Measurements

  1. Clearing the physical space (3 min)
    1. Sweep the room 119C for people, loose items, and other obstacles
    2. Close drapes and door. Turn of light
    3. Press white start button on the wall next to the red emergency stop
  2. Starting the computer and defining a new sample in the database (5 min)
    1. Start the computer (probably on) login with known user/passwd
    2. Start a browser e.g. Iceweasel (the Debian flavor of Firefox)
    3. Go to "Pab pgII data" bookmark. I.e. http://127.0.0.1/gonio-photometer/data
    4. Click the link "Add new sample" (under the picture)
    5. Fill out as much information as possible, if not isotropic define phi=0 for the sample
    6. Click button "Add new sample" (this can be edited later)
  3. Start the control program and turn on the lamp (1 min)
    1. Double click on the icon for "pgc with log" located on the desktop
    2. Click the tab for "manual control"
    3. Check the box in front of "id:1, halogen1" to turn on the lamp.
  4. Reference measurement (30 min warm-up and config + 40 min measurement)
    1. Click the tab labeled sample config
    2. Select sample #0 titled "No sample"
    3. Click the tab labeled measurement config & start
    4. Click tab job1
    5. Set "measurement path" to "beam-5.0deg"
    6. Change incidence angle to 0 0 0 0 0 0
    7. Repeat the above 2 steps for the tabs job 2..4
    8. In the left part of the program
      1. Click clear errors & warnings
      2. Click standby
      3. Click run twice (wait a couple of seconds in between)
    9. At the bottom of the screen, click start measurement
  5. Sample measurement (3 hours)
    1. Press the "off" button next to the run and standby under pgII main control
    2. Turn on room light, open door, mount sample
    3. Check so that you did not forget anything on the machine
    4. Close drapes and door, turn light off, press white start button
    5. In the pgc control program click the tab sample config
    6. Select your sample
    7. Click the tab labeled measurement config & start
    8. Click tab job1
    9. Set "measurement path" to "fullrot-400". Choose instead "refl-trans" for a non-opaque specular sample)
    10. Change incidence angle to 0 80 10 0 yourphi 0 (use phi=0 for isotropic samples)
    11. Repeat the above 2 steps for the tabs job 2..4
    12. In the left part of the program
      1. Click clear errors & warnings
      2. Click standby
      3. Click run twice (wait a couple of seconds in between)
    13. At the bottom of the screen, click start measurement
  6. Shut down
    1. Press the "off" button next to the run and standby under pgII main control
    2. Click the tab for "manual control"
    3. Uncheck the box in front of "id:1, halogen1" to turn off the lamp.
    4. Close down the pgc program
    5. Turn on room light, open door, remove sample

Local Post processing

The program mountain can be used for a lot of initial post processing on the pgII control machine.
Open a Konsole and type man mountain for a full list of capabilites.

Example of some typical actions:
Calculating reference beam intensity
mountain -t -n -w 235
-t means transmittance and should always be even if you are using it for a reflectance measurement
-n means no drawing
-w means write back to database
235 is the measurement id of your reference measurement

Calculating sample BTDF
mountain -t -n -w -rb 235 240
-rb 235 means use measurement id 235 as reference, this id must have had its intensity calculated per above
240 is the id of the measurement for which you want to calculate the BTDF

Calculating sample BRDF
mountain -r -n -w -rb 235 240
-r means reflectance

Plot a graph
mountain -r -rb 235 240 -fd MySampleBRDF.png
-fd MySampleBRDF.png defines the filename that will be for screen dumps during viewing (the keyboard
button prt scr dumps the screen)
Navigating the view in mountain can be clunky. Holding/clicking all three mouse buttons generate results.
Buttons F5-F8 generate effects.

Plot a graph in log scale
mountain -l -r -rb 235 240 -fd MySampleBRDFlog.png
-l sets log scale

Reduction of number of data points
mountain -sa 0.1 -r -rb 235 240
-sa angle smallest angle [deg] (closer values are averaged)

Bulk processing
It is possible to edit a list in a text editor and run it as one command in the Konsole, .
Example for a hardcoded batch run using id 291 as reference and 310 and 311 as measurements:
#!/bin/bash
mountain -t -n -w 291
mountain -r -n -w -rb 291 310
mountain -t -n -w -rb 291 310
mountain -r -n -w -rb 291 311
mountain -t -n -w -rb 291 311

Those 6 lines are saved in a file, e.g. bulkrun.sh, that file is given executable permission using chmod, and then
the file is executed in the shell by typing ./bulkrun.sh

Typical operation of our machine is to make a reference of all four channels and then measure a sample at
9 angles of incidence using 4 channels. A nicer way for doing 4 references starting at id 316 and 9 angles of incidence
#!/bin/bash
startId="316"
for i in `seq 0 3`;
do
   mountain -t -n -w $((startId + $i)) # Calculate the reference
  for j in `seq 0 8`;
  do
    mountain -t -n -w -rb $((startId + $i)) $(($startId+4+$i*9+$j))
    mountain -r -n -w -rb $((startId + $i)) $(($startId+4+$i*9+$j))
  done
done

Then only the startId variable has to be changed. It should not be hard to replace the "316" with a $1 or something to
make the script take an argument.


Profile data for in-plane plots
Profile plots can be obtained using the mountain interpolation parameter. For example a transmittance profile can be obtained using
mountain -n -rb 225 -ip 1,0,90,270.0,0.2,profileT.dat -t 226

-n no display (write only to file)
-rb 225 reference beam measurement
- ip interpolate
   1 interpolation type Delauny triangulation
   0 constant ( phi=0 degree)
   90,270.0 theta range
   0.2 interpolation interval
   profile.dat output filename
-t 226 transmission measurement record


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