Miniature Leaf Spectrometer (CI-710)

• Wide range spectrum (400-1000nm)
• 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

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.

Physical
Dimension :	89.1 mm x 63.3 mm x 34.4 mm
Weight:	290 grams
Detector Specifications
Detector:	Toshiba TCD1304AP Linear CCD array
Detector range:	400-1000 nm
Pixels:	3648 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:	16 bit
Dark noise:	50 RMS counts
Corrected linearity:	>99.8%
Sensitivity:	130 photons/count at 400 nm; 60 photons/count at 600 nm
Spectroscopic
Wavelength range:	Grating dependent
Optical resolution:	~0.3-10.0 nm FWHM (grating dependent)
Integration time:	3.8 ms - 10 seconds
Dynamic range:	2 x 108 (system), 1300:1 for a single acquisition
Stray light:	<0.05% at 600 nm; 0.10% at 435 nm
Electronics
Power Supply:	USB Powered via PC
Power consumption:	250 mA @ 5 VDC
Data transfer speed:	Full spectrum to memory every 4 ms with USB 2.0 port
Inputs/Outputs:	Yes, 8 onboard digital user-programmable GPIOs
Analog channels:	No
Auto nulling:	Yes
Breakout box compatible:	No
Trigger modes:	4 modes
Strobe functions:	Yes
Connector:	22-pin connector
Computer
Operating systems:	Windows 98/Me/2000/XP, Mac OS X and Linux with USB port
Computer interfaces:	USB 2.0 @ 480 Mbps (USB1.1 compatible)

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 400-1000nm.

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.

• CI-710 Spectrometer Main Unit
• CI-710 Leaf Probe
• Extra light bulb
• Communication Cables
• Operation Software