Veris Technologies VIS_NIR Spectrophotometer Probe - Operating Instructions - Manual (Page 29)

OM17-P4000VIS-NIR
4-8
How to know you’re collecting high quality NIR measurements:
a) Log light and GPS lights are both green
b) Ref check light is green
c)
Spectrum absorbance doesn’t jump as the probe is pushed down
d) Absorbance spectrum shows a typical soil spectra pattern (Figure
52), and is changing slightly as the data is collected.
e) External references can be attached to probe at any time in Data
Acquisition mode. Absorbance should be highest for ER3 and
lowest for ER4.
f) Wear plate window is not broken, or cracked. This is caused by
excess wear, or rocky fields. Be sure to check window during
these situations and replace probe wear plate if necessary.
3. Data Extraction
– The spectra and auxiliary data are read out of the compact format
(bytestream) file and averaged, then the output is stored in an ASCII format. EC data is
extracted into file named ec.txt. The extraction program will extract all the bytestream
files and apply the appropriate transform, then output the data into a single text file.
Once all the data has been processed, indicated by a green complete light, click on
close window or F12 to return to main interface.
4. Filtering -The spectra are compressed using principal components compression, and
outliers are removed. Maps of each principal component (up to 10) are displayed, and
the results of the PC analysis and filtering are output to ASCII formatted files.
Transform which
will be applied to
field files created
in the acquisition
(bytestream
files).
Spectrum
acquired using
LOG mode
during
acquisition.
Reference check
spectrum
acquired during
acquisition.
Number of
references and dark
spectra taken during
acquisition.
All reference
spectrum taken
during acquisition.
All dark spectrum
taken during
acquisition.
Output file that contains
transformed field absorbance
spectrum taken during LOG
mode of acquisition.
Figure 11