6400-18A RGB Light Source


LI-COR is excited to introduce the new 6400-18A RGB (Red, Green, Blue) Light Source, designed to be used with the 6400-17 Whole Plant Arabidopsis Chamber, 6400-22 Lighted Conifer Chamber, 6400-24 Bryophyte Chamber, or with custom chambers (requires user-designed mounting bracket) and other LI-COR clear-topped chambers. Package pricing is available for many chambers, when purchased in combination with the 6400-18A.

  • The 6400-18A and 6400-17 (6400-17L Package) provide a powerful new tool for light response studies using whole rosettes.
  • The 6400-18A and 6400-22 (6400-22L Package) allows for light response curve measurements on short-needle conifers at intensities equivalent to full sunlight.
  • The 6400-18A and 6400-24 (6400-24L Package) allows loose plant material to be held in a shallow well for mass photosynthesis measurements, and to explore the response to both light intensity and quality.

Independent Control of LED Output

The 6400-18A features LEDs with independent control of the intensity and percent of red, green, and blue light. White light* can be achieved by using equal output of red, green, and blue LEDs. Select any intensity (to 2000 μmol m-2 s-1) of a pre-defined color, or define your own blended color, by selecting the proportion of red, green, and/or blue light to be applied to the sample. As an example, for stomatal kinetics studies, you could measure stomatal conductance with 100% red, 100% green, and 0% blue, as compared to using 100% blue light. The 6400-18A can also be easily configured to emulate the output of the 6400-02B Red-Blue Light Source for comparison studies.

Turns light source ON/OFF
Sets output (μmol m2 s-1 of chosen color
Adjusts lamp output automatically to match measured PAR output of external quantum sensor
Color Picker, including 6400-02B emulation
Set Proportion of R, G, and/or B
Choose Red, Green, Blue, White, Cyan, Magenta, Yellow, Red-Blue Light Source, or define your own colors

The LED tile in the 6400-18A is configured to ensure uniform light distribution at the leaf surface. LEDs minimize the influence of the light source on the leaf temperature, as they have low heat generation compared to other light sources. The 6400-18A is calibrated on an integrating sphere by measuring total output and spectral quality with a spectroradiometer. The output is used to calibrate a silicon feedback photodiode built into the light source (below). The feedback photodiode ensures an accurate light intensity by adjusting the light source as required. The light source also has temperature correction and linearization circuitry that are calibrated as well, to ensure the accuracy of radiant output at all rated operating temperatures and intensities. The 6400-18A mounts easily to the 6400-17 or 6400-24; the propafilm covered plate used with those chambers attaches directly to the Light Source. This method of attachment ensures that the geometry between the plant sample and the light source is repeatable for every measurement.

Software Automation

RGB Light Source Software Screenshot

The 6400-18A is completely integrated with the LI-6400/6400XT. The light source intensity can be changed for light response curves, set to match external PAR sensor readings, or held constant while other environmental conditions are altered. Light and CO2 response curve autoprograms are built into OPEN software that can be used to automatically control and collect data for unattended curves.

Simply set the desired chamber environmental conditions and light intensities from the 6400-18A. The autoprogram prompts for the light levels at which measurements will be logged, the minimum and maximum time between measurements, and the stability parameter(s) that must be achieved before a measurement is logged. The 6400-18A light levels will be set, and all other environmental controls are maintained during the experiment.

OPEN 6.1 (or above) software is required, which contains a dedicated configuration for the 6400-18A RGB Light Source.

*NOTE: OPEN 6.1 (or above) can be installed on 200 MHz (ver 5.x) or 400 MHz (ver 6.x) digital boards. Older boards require a digital board upgrade — contact LI-COR for details.

6400-18A RGB Light Source Specifications

6400-18A RGB Light Source Specifications Red Green Blue
Controllable Output Range (white): up to 4000 µmol m-2 s-1 at 25°C (typical) Max. Output (µmol m-2 s-1) 2000 1350 1800
Output Spatial Uniformity: +5% to -15% of the mean over 90% of the area (typical) Peak Wavelength (nm) 632 ± 5 522 ± 8 470 ± 10
Maximum Power Consumption: 60W Half Power Bandwidth (nm) 16 35 24
Operating Temperature Range: 0 - 50°C
Operating RH: 0 - 95%, non-condensing
Size: 12.4H 9.0W 9.5L cm (4.9 3.6 3.7 in)
Weight: 0.54 kg (1.20 lb)

6400-18A Brochure

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