A new add-on module for Ocean Optics' (www.OceanOptics.com) SpectraSuite Spectrometer Operating Software allows users of the company's miniature spectrometers and Jaz optical sensing systems to calculate Photosynthetically Active Radiation (PAR), an important parameter for evaluating the effect of light on plant growth. SpectraSuite-PAR uses the absolute irradiance spectrum (captured by the spectrometer) of the light incident on plants and other samples and conveniently converts the irradiance values from µW/cm2 (microwatts per square centimeter) to µmol/m2/s (micromoles per square meter per second), the measurement unit more commonly used for PAR analysis.

In addition to calculating total PAR, SpectraSuite-PAR allows users to define up to five "wavelength bins" (the range of wavelengths to be covered in each data bin), which can be correlated to different phases of plant growth. For example, a bin can be configured over the 400-480 nm range to capture the effects of the blue region of the spectrum, which is typically associated with early stages of plant growth. Also, customers can calculate both the percentage of light in each bin and the red/far red ratio, a parameter associated with plant development and structure.

SpectraSuite-PAR is a particularly powerful analytical tool when used as part of a field-portable Jaz sensing system configured for horticultural applications. Jaz is a family of modular, stackable components -- a typical setup for field use is about the size of a few decks of cards -- that share common electronics and communications. At its heart is a miniature CCD-array spectrometer, or light measuring device, available with user-selected grating and slit options optimized for a variety of optical sensing application needs. Also incorporated into the Jaz stack is a powerful microprocessor and onboard display with data logging capability, so that full spectra data can be acquired, processed and stored to an SD card without the need for a PC. Jaz irradiance measurement software is also available and nicely complements the SpectraSuite-PAR functions.

SpectraSuite is the standard operating software for Ocean Optics spectrometers. The modular, Java-based spectroscopy software platform operates on Windows, Macintosh and Linux operating systems. The SpectraSuite interface is virtually identical on all operating systems yet retains the familiar appearance of an application native to each OS. SpectraSuite has a wide range of standard functions, from managing multiple USB spectrometers and identifying center wavelength and other peak metrics to calculating color parameters such as CIE illuminants and Color Rendering Index and measuring photometric values such as luminous flux and photopic standard observer functions.