Leaf Chamber Covering

Printable PDF: Propafilm Leaf Chamber Covering

Installation guide to replace the propafilm on the leaf chamber.

The protective covering on the upper leaf chamber is a Propafilm® C material (ICI Americas, Inc., Wilmington, DE). You will need to replace the covering if it becomes torn or punctured, or excessively dirty. Replacement Propafilm (LI-COR part #250-01885) and double-sided tape (part #212- 04341) can be found in the spare parts kit.

To replace the Propafilm:

  1. Unhook the PAR sensor connector from the port on the side of the sensor head by gently pulling straight out. You will need to remove the tripod mounting bracket, if attached, to access the connector.
  2. Remove the upper half of the leaf chamber using the 3/32” hex key provided in the spare parts kit. The upper half of the leaf chamber is secured by two long screws.
  3. Figure 1‑1. Remove the two screws from the upper half of the leaf chamber.
  4. Remove the old Propafilm covering and tape from the chamber surface. The tape has a fairly strong adhesive; if it does not peel off readily, use a mild solvent (i.e., acetone) to help dissolve the adhesive. Do not use a blade or other sharp instrument to remove the tape, as you could damage the surface of the chamber, thereby making it difficult to achieve a tight seal.
  5. Cut a strip of the double-sided tape that is slightly longer than the leaf chamber. Lay on a flat cutting surface, adhesive side up. The tape may be curled slightly; tape the corners down with cellophane tape, if necessary.
  6. Lower the top surface of the chamber onto the tape and press firmly. Trim the tape around the outer and inner edges of the chamber. To get a clean cut, use a fresh blade (an Exacto knife works well) and make your first cut as close to the edge as possible.
  7. Figure 1‑2. Trim tape at leaf chamber edges.
  8. Remove the backing from the tape and smooth any bubbles that may have formed.
  9. Cut a 6" (15 cm) square piece of Propafilm. Stretch the film until taut on a flat, clean surface. Again, you may want to tape the corners with cellophane tape to secure it to the cutting surface.
  10. Lay the leaf chamber onto the Propafilm.
  11. Turn the chamber over and smooth the film. Lance any bubbles that may have formed.
  12. Trim the film around the outer edge of the chamber. Make your first cut as close to the edge as possible.
  13. Reassemble the leaf chamber assembly.