What's what
The LI-6800 measures leaf-level gas exchange with three chambers: the 6800-01/A fluorometer, the 6800-12/A small leaf chamber, and the 6800-13 large leaf chamber. Here we describe how to use these chambers for leaf-level gas exchange measurements, as well as the small plant chamber, large leaf chamber, sprig adapter kit, bryophyte chamber, insect chamber, and custom adapter kit. Each chamber uses a flow path similar to that shown in An open gas exchange system.
Both the small and large leaf chambers, when not equipped with a light source, have a clear Propafilm™ top that can be used under ambient light. Both also can be outfitted with a light source. The light source on the 6800-01A fluorometer is permanently attached and cannot be removed. It can be operated as a fluorometer or standard light source. All leaf chambers feature one or more leaf temperature thermocouples that make contact with the bottom of a leaf to measure its temperature during measurements and a photodiode that measures light in the chamber.
Fluorometer chamber
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 Measuring chlorophyll a fluorescence for installation instructions and a list of components.
Small leaf chamber and light source
The small chamber features a transparent Propafilm™ top window. It accommodates one fine wire thermocouple to measure leaf temperature. A GaAsP light sensor measures PAR in the chamber. It is compatible with the 3×3 cm light source. Aperture inserts limit the opening to 3×3 cm, 2×3 cm, or 1×3 cm. See Installing the small leaf chamber for details. The chamber includes the following items:
| Description | Quantity | Part Number |
|---|---|---|
| Chamber | 1 | 9968-264 |
| 1×3 cm Aperture Inserts | 2 | 9968-294 |
| 2×3 cm Aperture Inserts | 2 | 9968-295 |
| 3×3 cm Aperture Inserts | 2 | 9968-296 |
| Spares Kit | 1 | 9968-269 |
| O-ring; 6×1.5 mm | 1 | 192-14314 |
| O-ring; 48×1.5 mm; for Apertures | 2 | 192-16680 |
| Light Source Gaskets1 | 3 | 6568-071 |
| 3×3 cm Aperture AP Gaskets (white upper/lower) | 2 | 6568-511 |
| 2×3 cm Aperture AP Gaskets (white upper/lower) | 2 | 6568-562 |
| 1×3 cm Aperture AP Gaskets (white upper/lower) | 2 | 6568-560 |
| 3×3 cm Aperture PE Gasket (white upper) | 4 | 6568-429 |
| 3×3 cm Aperture NP Gasket (black lower) | 4 | 6568-384 |
| 2×3 cm Aperture PE Gasket (white upper) | 4 | 6564-156 |
| 2×3 cm Aperture NP Gasket (black lower) | 4 | 6564-028 |
| 1×3 cm Aperture PE Gasket (white upper) | 4 | 6568-584 |
| 1×3 cm Aperture NP Gasket (black upper) | 4 | 6568-583 |
Large leaf chamber and light source
The 6×6 cm chamber features a clear Propafilm™ top window. It holds two fine wire thermocouples to measure the leaf temperature. An internal, upward facing GaAsP light sensor measures PAR in the chamber. It is compatible with the 6×6 cm light source. See Installing the large leaf chamber for details. The chamber includes the following items:
| Description | Quantity | Part Number |
|---|---|---|
| Chamber | 1 | 9968-159 |
| Large Light Source Adapter Plate | 1 | 9968-209 |
| Large Light Source Chamber Adapter Kit | 1 | 9968-189 |
| Adapter Plate | 2 | 9868-209 |
| Mounting Screws; M3×0.5 8 mm | 4 | 150-07475 |
| Bottom Chamber Light Source Adapter Kit | 1 | 9968-311 |
| Light Source Spacer | 1 | 9868-245 |
| Screws; M3×0.5 10 mm | 4 | 150-15307 |
| Spares Kit | 1 | 9968-207 |
| O-ring; 6×1.5 mm | 1 | 192-14314 |
| O-ring; AS-154 Viton 75 | 1 | 192-12205 |
| 6×6 cm AP2 Gasket (white upper/lower) | 2 | 6568-513 |
| 6×6 cm NP Gasket (black lower) | 3 | 6568-210 |
| 6×6 cm PE Gasket (white upper) | 6 | 6568-463 |
| Thermocouple Hole Plug | 2 | 6568-523 |
| Propafilm Kit | 1 | 9964-151 |
