Lab Chromameter (CR-410) SOP

Submitted by dylan on Wed, 2007-10-03 22:24.

Calibration of the CR-410

  1. power on the unit, and press the 'Cal' button
  2. place the unit on the white standard calibration tile
  3. verify the values on screen match the "C" light standard values listed on the calibration tile case
  4. press the measurement trigger button
  5. the unit will take three samples, and will enter measurement mode

Downloading data from the sensor head or data processing unit.

  1. Transfer data from sensor head to data processing unit (this erases the data from the sensor head). This is done by connecting the two units and then importing data from the sensor head
    1. press 'Option'
    2. select 'Import'
    3. select 'NEW'
    4. press 'Enter'
  2. Attach data processing unit (DPU) to serial port and open ut400.exe: this can be accomplished in windows / VMware / wine. If you are using wine, you will need to:
    1. configure the serial port (http://www.winehq.com/site/docs/wineusr-guide/misc-things-to-configure#AEN408)
    2. copy msvcirt.dll from a working windows install in the windows/system32/ folder in your wine home directory
    3. Start the program with wine:
      wine ~/.wine/drive_c/Program\ Files/Minolta/CR-400\ Utility/ut400.exe
  3. Set the DPU to 'remote mode' by first pressing the 'index set' button and scrolling down to this setting.
  4. Connect to the DPU.
  5. Set an output target (use a text file for maximum compatibility).
  6. Click on the 'Intrument...' button, and then choose the 'Upload' option.
  7. Upload the data, note that if there are several sets of data on the device (pages) you must select the appropriate page first.
  8. click on 'Save As' in the text output window, and save the results to a file.
  9. The data should be saved in XYZ colorspace

Deleting old data from the DPU

Chromameter Soil Colors in XYZChromameter Soil Colors in XYZ (see below)

 
Processing in R:

# example processing:
# note that the row name corresponds to the sample_id

require(colorspace)
x <- read.csv('data_dump_4-7-2007.csv', header=FALSE)
c <- data.frame(id=x$V1, X=x$V2, Y=x$V3, Z=x$V4)

# cast to XYZ object
c.xyz <- XYZ(c$X, c$Y, c$Z)

# plot colors in XYZ colorspace
plot( c.xyz, cex=1.5)

 
Other examples of processing color data in R

 
Related Literature

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