Tech Specs

The Our Sci Reflectometer is a robust, general purpose, ten wavelength device for measuring spectral reflectance from liquids (e.g. milk), flat objects (e.g. leaves) or solids (e.g. soils, produce).

The circuit has an on-board lithium battery charger (designed for a 3.7V 18650 Li battery), current-controlled pulsed LEDs to illuminate the sample, as well as an optional hall effect sensor, contactless temperature sensor and temp/pressure/rh sensor (BME280).

Key Features
  • 10-wavelength output not affected by ambient light
  • Robust and field-ready
  • Connects to Survey Stack (Our-Sci's open-source software) to collect, share, and display results
  • Connects to any Android device wirelessly using Bluetooth or wired USB On The Go
  • Includes a wall charger and an internal 3400 mAh battery
  • Fully open source and modifiable


Applications
Designed for use with:
  • liquids in 5 mL or 0.7 mL square cuvettes
  • liquid colormetric measurements (example: pH change)
  • cell density (940 nm)
    • examples: milk fat concentration; spectral properties of juices, wines, etc.
  • soil or other bulk solids
  • soil carbon estimation (requires calibration)
  • soil color estimation
  • solid objects (fruits, veggies)
  • spectral signatures for nutrient estimation (requires calibration)
  • leaves or other flat objects
  • NDVI (greenness) in leaves
  • relative carotenoids, anthocyanins, or other color-related compounds


Default Output
  • Reflectance at all wavelengths (normalized from 0 - 10,000)
  • Chlorophyll fluoresence and any fluorescence with excitation <700 nm and flurorescence >700 nm
  • NDVI (greenness) in leaves


Sensor Detail
Reflectance hardware:
  • 10 wavelength (nm): UVB - 365; Visible - 385; 450; 500; 530; 587; 632; Far Red; NIR - 850; 880; 940
  • 2 detectors (nm range): 300-700; 700-1100

  • Additional Sensors:
    • Temperature (full range: -40 - 85 C, accuracy within 0 - 65 C: +/- 1C)
    • Relative Humidity (range: 0-100%, accuracy: +/-3%)
    • Pressure (range: 300-1100 hPa, accuracy: +/-0.25%)
    • VOCs (range: 0 - 500 IAQs, accuracy: +/- 15%)
    • Audio jack for additional inputs / outputs. Examples include soil senseors, moisture sensors, etc.


Case
  • 13.9 cm x 5.2 cm x 4.6 cm
  • 3D printed PETG
  • Temperature resistant up to 60° C / 140° F


Calibration
All instruments come individually calibrated to reduce instrument-to-instrument variation, as well as variaton by time and by temperature.

For long-term shifts in signal intensity, users may easily recalibrate. If you're working with several machines that you would like calibrated to the same standard, please contact hardware-support@our-sci.net.


All of our products are open source

To build this devices yourself, you will need the following documentation: