What's what

The 6800-01A fluorometer is a combined chamber and light source that induces and measures fluorescence from a leaf or an aquatic sample with the aquatic chamber. In the leaf configuration, it includes aperture inserts to limit the opening to 6 cm2 or 2 cm2. See Installing the fluorometer chamber.

Fluorometer chamber

The fluorometer mounts to the LI-6800 head. It has two operating configuration: a light source and leaf chamber (see Figure 8‑4), or light source and aquatic chamber (see Measuring assimilation from aquatic samples).

Figure 8‑4. The 6800-01A fluorometer with leaf chamber apertures and the leaf temperature thermocouple.
Table 8‑1. 6800-01 and 6800-01A fluorometer LEDs.
LED Center Wavelength Purpose
Blue Actinic 475 nm Steady-state
  • Maximum steady-state intensity is 1000 µmol m-2 s-1
Red Actinic 625 nm Steady-state, saturating flash, and multiphase flash
  • Maximum steady-state intensity is 2000 µmol m-2 s-1
  • Maximum saturating flash intensity is 16,000 µmol m-2 s-1
Red Modulating 625 nm Modulated measuring
  • Modulation is 1 µs wide pulses with programmable frequency from 1 Hz to 250 kHz
  • Maximum steady-state peak intensity is 100 µmol m‑2 s-1, steady-state average intensity depends on peak intensity setting and modulating frequency setting
Far-Red 735 nm Steady-state and dark-pulse
  • Maximum steady-state intensity is 20 µmol m-2 s-1
Figure 8‑5. Typical spectral output of the blue, red, and far red LEDs in the fluorometer.

Spares kit

The fluorometer includes a spares kit (part number 9968-270) with the following items. Apertures are used in leaf applications.

Description Quantity Part Number
Fluorometer Chamber 1 9968-266
6 cm2 Aperture Inserts 2 6800-50
2 cm2 Aperture Inserts 2 6800-51
Fluorometer Spares Kit 1 9968-270
O-ring; 6×1.5 mm; for Leaf Temperature Thermocouple 1 192-14314
O-ring; 35×1.5 mm; for Apertures 2 192-16851
6 cm2 Aperture AP1 Gaskets (white upper/lower) 2 6568-512
2 cm2 Aperture AP Gaskets (white upper/lower) 2 6568-566
2 cm2 Aperture PE Gasket (white upper) 4 6564-202
2 cm2 Aperture NP Gasket (black lower) 4 6564-196
Fluorometer Gasket Kit   9968-208
6 cm2 Aperture PE Gasket (white upper) 4 6568-436
6 cm2 Aperture NP Gasket (black lower) 4 6568-413