REPORT
DESIGN OF THE PREMIVM OPTICAL TRANSDUCER
Based on the laboratory measurements on the chemical standards of these particular
representatives of polyphenols, design of the PREMIVM optical transducer has been
identified (see M7 deliverable).
We decided to use fluorescence signal excited by four different LEDs: 280nm, 315nm,
375nm and 435nm and reflectance signal generated by miniature xenon lamp. The
detection is equipped by Hamamatsu spectrometer C11009MA, UV selective sensor
SG01M-Lens and blue enhanced photodiode OSD15-5T.
During first part of the project, we designed optical parts of the device. With designed
optical head we can measure following parameters: 1) Reflectance – as a light source
we use miniature incandescent xenon lamp with wide and homogenous spectrum in
range 380-780nm measured by spectrometer, to further increase measurement range in
UV we add separate UV sensor for reflectance measurement at 280nm and 315nm, 2)
Chlorophyll fluorescence - measured at 680nm and excited with two light sources
(435nm, 375nm). 3) Fluorescence signal of polyphenols – excited with 280nm and
315nm LED and measured with separate sensor at 390nm
Fig.1 Design of optical transducer.
Bill of materials:
XENON LAMP
LED435
LED375
LED280
LED315
SP325
UG11
OPTICAL FIBER
SG01M-LENS
OSD15-5T
BP390
- miniature xenon lamp, BARTHELME
- blue LED, peak wavelength 435nm, LED435-12-30, RLT
- uv LED, peak wavelength 375nm, XRL-375-5E, RLT
- deep uv LED, peak wavelength 280nm, UVTOP280, SETI
- deep uv LED, peak wavelength 315nm, UVTOP315, SETI
- short pass interference filter, 325nm, ZUS0325, ASAHI SPECTRA
- uv band pass filter, Ionically colored glass, UG11, SCHOTT
- optical fiber of spectrometer module, C11009MA, HAMAMATSU
- ultraviolet selective SiC based UV sensor, SCITEC
- blue enhanced silicon photodetector, CENTRONIC
- band pass filter FB390-10, THORLABS
REPORT
Optical transducer is connected to sample holder with hexagonal homogenizing rod.
Need of homogenizing rods has following reasons:
-all light sources are aiming at the same spot (large heterogeneity of the sample)
-minimizing errors caused by sample shape (different light beam angles of the light
sources)
Designed probe has other advantages:
-protects internal optics and electronics
-can be easily cleaned
-can be used for liquid samples in future
Fig. 2: Design of sample holder
Sample holder was designed to follow the requirement to keep sample as much as
possible at same position without need of removing berry from the cluster (Fig. 2).
REPORT
DESIGN OF THE ELECTRONICS
Electronics controlling the PREMIVM instrument is based on ARM7 microprocessor.
There is fast high accuracy analog to digital converter for spectrometer readout and
additional high accuracy converter for photodiode sensors. Because the measured
intensities of UV fluorescence are very low, integrating converter is used. Very low signal
can be measured using longer integration times. Integrated LED driver is controlling 4
excitation LEDs and xenon lamp producing broad band spectrum of light for reflectance
measurement. Other components of the instruments are:
-high capacity flash memory
-GPS receiver
-real time clock
-integrated high capacity Li-ION battery with USB charging capability
User interface is designed with graphical color display and touch screen.
Fig. 3: Schematic of the PREMIVM instrument
REPORT
Fig. 4: PREMIVM instrument
REPORT
DESIGN OF THE FIRMWARE
To switch the PREMIVM instrument on, press the Power button until the logo shows up.
Main screen:
Shows calculated content of selected wine
components
Measure –measures all parameters and calculates new values of components
concentrations
REPORT
Calibration – for device calibration follow on screen instructions
REPORT
Main menus:
Device:
Calibrate – calibration can be run any time by pressing Device->Calibrate after inserting
appropriate standard in the clip.
Also include how often should calibration be performed.
Data:
Browse – displays data browse dialog box
Erase – use this menu to erase internal data memory
Memory info – displays information on used memory.
Settings:
Time:
Set the actual time and date (all data files are stored
by time and date signature).
To change time, touch on one of the values and
adjust it using the arrows.
Miscellaneous:
Backlight intensity – move slider to adjust backlight
intensity
Backlight time-out – move slider to adjust backlight timeout (time of inactivity required before backlight will dim
out to save battery life).