Plant Science Tools


Miniature Leaf Spectrometer

The CI-710 Miniature Leaf Spectrometer is designed to measure the transmission, absorption, and reflection of light by biological substances within a wide range of wavelengths that cover visible and Near Infra-Red (NIR) light. Transmission and absorption spectrum measurements are the most common applications of spectrometers. The spectrum can be used for the quantification of chemical concentrations, color analysis, the study of photochemical reactions such as photosynthesis, and the quantification of physical or optical properties such as film thickness, index of refraction, and extinction coefficient.


Part of the power of the CI-710 Miniature Leaf Spectrometer is its ability to scan and record across a wide spectrum, from 400-950 nm. Many researchers wish to analyze multiple, discrete peaks or integrate across wavelength bands. These functions are readily accomplished with the SpectraSnap! software that ships with the CI-710.

Other users of the CI-710 have expressed a need to rapidly estimate vegetation properties using published and accepted indices. These indices include: estimates of greenness like the widely-used Normalized Difference Vegetation Index (NDVI); plant stress, such as the Plant Senescence Reflectance Index (PRSI); pigment concentrations, including carotenoids and anthocyanins; and leaf water status estimated by the Water Band Index (WBI).

Now, with SpectraSnap!, these indices and others can be easily and simultaneously measured. SpectraSnap! gives the CI-710 user the power of many single-measurement instruments in one package. Researchers can also add their favorite algorithms to the library.

Why SpectraSnap!

Since its introduction, CID's compact and light-weight CI-710 hardware has simplified the process of collecting spectral signatures from plant tissue. Now SpectraSnap! simplifies data analysis by offering several real time computations in an intuitive and easy-to-operate system.

Save Time

Insert the sample into the CI-710 hardware and the selected calculations are instantly displayed along with raw and averaged spectroscopic data. Press Stop to pause the live stream or Save to record the on-screen measurement. It's that easy.

Ready to use out of the box. Flexible when you need it.

Choose the calculations to display from a convenient selection of popular vegetation indices (NDVI, PRI, CRI, ARI, etc) and/or define your own calculations to target specific areas of interest.

  • One-touch spectrometry in the field
  • Non-destructive measurement
  • Fast and sensitive

Preprogrammed Indices

Reflectance Mode

  • Anthocyanin Reflectance Index 1
  • Anthocyanin Reflectance Index 2
  • Carotenoid Reflectance Index 1
  • Carotenoid Reflectance Index 2
  • Structure Intensive Pigment Index
  • Flavonols Reflectance Index
  • Chlorophyll Normalized Difference Vegetation Index
  • Carter Index 1
  • Carter Index 2
  • Greenness Index
  • Gitelson and Merzlyak Index 1
  • Gitelson and Merzlyak Index 2
  • Lichtenthaler Index 1
  • Lichtenthaler Index 2
  • Normalized Difference Vegetation Index
  • Normalized Pigment Chlorophyll Index
  • Normalized Phaeophytinization Index
  • Simple Ratio Pigment Index
  • Transformed CAR Index
  • Triangular Vegetation Index
  • Zarco-Tejada & Miller Index
  • Modified Red Edge Simple Ratio Index
  • Red Edge Normalized Difference Vegetation Index
  • Vogelmann Red Edge Index 1
  • Vogelmann Red Edge Index 2
  • Vogelmann Red Edge Index 3
  • Photochemical Reflectance Index
  • Plant Senescence Reflectance Index
  • Water Band Index

Absorbance Mode

  • Modified Chlorophyll Absorption in Reflectance Index 1
  • Modified Chlorophyll Absorption in Reflectance Index 2

Theory of Operation

CI-710 is a USB (Universal Serial Bus) powered spectrometer with operating software, and a leaf probe attachment. A broadband light source is attached on the leaf probe and can be conveniently placed in two positions for transmissive or reflective measurements. The spectrometer module takes the light from the leaf probe attachment through a fiber optic cable, disperses the light by a diffraction grating, and projects the wavelength dispersed light onto a CCD array. Each pixel of the CCD array thus corresponds to a specific wavelength of light. The operating software, SpectraSuite, displays the light intensity of each pixel of the CCD array.

Five spectroscopic measurements can be performed by CI-710:

Intensity (I) shows the electrical response of each CCD pixel to a specific wavelength of light coming off the fiber optic cable. It is essential to collect the intensity of the light source at the full wavelength range, referred to as the reference spectrum in SpectraSuite as it is required in calculating transmittance, absorbance, reflectivity, and irradiance.

Transmittance (T) is the fraction of the incident light passing through a sample, such as a leaf. When the intensity of the incident light is Io, and the intensity of light passing through the sample is It, the transmittance, T, is then expressed as T = It / Io. The CI-710 software suite can automatically calculate and plot the transmission spectrum with the reference spectrum (the intensity profile of the light source) stored.

Absorbance (A) is related to the transmittance as A = - log T = -log(It / Io). Absorbance is commonly denoted in optical density (OD) as it is linearly proportional to the amount of light absorbing sample in the light path length (Beer-Lambert law). For example, in a standard 1-cm cuvette, a sample with an OD of 2 is twice as concentrated as a sample with an OD of 1. But note that the intensity of light transmitted from a sample with an OD of 2 is only 1/10 of that from a sample with an OD of 1. Transmission and absorption spectrum measurements are the most common applications of spectrometers. The spectrum can be used for the quantification of chemical concentrations, color analysis, the study of photochemical reactions such as photosynthesis, and the quantification of physical or optical properties such as film thickness, index of refraction, and extinction coefficient.

Reflectivity (R) is the fraction of incident light that is reflected from a sample. Depending on the purposes of the study, reflectivity can be measured for reflection at a specific angle from the sample, or the entire reflected hemisphere. The leaf probe attachment of CI-710 is not designed to measure the directional reflectivity. Nonetheless, it can be used to measure the absorption spectrum of surface substance of reflective or opaque samples.

Irradiance (Ir) is the amount of energy at each wavelength from a radiant sample. The relative irradiance is related to the radiant energy per unit area (watt cm-2) illuminating the sample. Common applications include characterizing the light output of incandescent lamps, or sunlight.


  • Wide range spectrum (400-950nm)
  • High resolution and real time high speed scanning
  • Very high sensitivity; ideal for fluorescence and other low light level applications
  • USB interface
  • Flexible fiber optic cables with connections to a variety of probes for different applications
  • Integrating time = 3.8 ms - 10 seconds
  • Lightweight and fully portable


Dimension: 89.1 mm x 63.3 mm x 34.4 mm

Weight: 975g

Operating Environment: -30° to 70° C storage, -10° to 50° C Operation,
0% - 90% noncondensing humidity

Minimum Leaf Size: 20mmx20mm

Detector Specifications

Detector: Toshiba TCD1304AP Linear CCD array

Wavelength Range: 400-950nm

Pixels: 3,648 pixels

Pixel Size: 8 μm x 200 μm

Pixel Well Depth: 100,000 electrons

Signal-To-Noise Ratio: 300:1 (at full signal)

A/D Resolution 16bit

Dark Noise: 50 RMS counts

Corrected Linearity: >99.8%

Sensitivity: 130 photons/count at 400nm; 60 photons/count at 600nm


Optical Resolution: ~0.3-10.0 nm FWHM (grating dependent)

Integration Time: 3.8ms - 10 seconds

Dynamic Range: 2 x 106 (system), 1300:1 for a single acquisition

Stray Light: <0.05% at 600 nm; 0.10% at 435 nm


Power Supply: USB Powered via PC

Power Consumption: 400 mA @ 5 VDC

Data Transfer Speed: Full spectrum to memory every 5 ms with USB 2.0 port

Trigger Modes Automatic & manual

Operating Systems: Windows 7 & 8 with USB

How to Use it

Simply clamp the CI-710LP onto the desired leaf to yield a full complement of spectrographic data on leaf transmission, reflectance, and absorbance.
The CI-710 has many applications in agriculture and environmental studies; including monitoring moisture content in leaves and protein content of crops.

The CI-710 has a compact optical bench coupled to a Linear CCD array detector. It accepts light energy transmitted through single strands of optical fiber and disperses the light via a fixed grating across the CCD array, which is responsive from 400-950nm. The CI-710 can be connected to an object such as a leaf, and can be scanned to obtain graphic outputs or digital data readings of the transmission, reflection and absorption spectra.

In the Box

The CI-710 Miniature Leaf Spectrometer includes:

  • CI-710 Spectrometer Main Unit
  • CI-710 Leaf Probe
  • Companion Windows 10™ Tablet
  • Communication Cables
  • Operation Software