CAB Tubes with end caps. Drill Guide & special bit are shown at right.

Minirhizotron Observation Tubes are available in standard and custom lengths, with and without pre-installed end caps, with and without etched indexing marks, and made of two different materials.

CAB (Cellulose Acetate Butyrate) is available in two diameters: 2-inch inside diameter (ID) for the BTC-2 and BTC-100X Cameras and 1.125-inch ID for the BTC-1.125 Camera. It has exceptional toughness, dimensional stability, low water absorption, excellent weather resistance, and good clarity. It is adequately clear for most research and more flexible than acrylic tubing.

Acrylic is more brittle but has reasonable toughness, good stability under variances of heat, cold and moisture, and excellent clarity. Extruded Acrylic is more expensive to ship, however, in order to guard against breakage.

End Caps are custom manufactured, internally mounted, and seal tested against water and soil entry. The leading exterior edges of the cap are beveled for easy installation and minimal disturbance to the surrounding soil bed.

The Index Hole Drill Guide allows a perfect match between the indexing Handle cap and placement of the index hole in the tube. A specially sharpened drill bit is provided to avoid splitting the plastic. If the Indexing Handle System is not being used, index marking can be etched on the tube surface.

The standard length of Minirhizotron tube stock is 6 feet. Smaller lengths are also available. For longer tubes, BTC can machine tube sockets for you to glue the tube sections together in the field to create up to 18 foot lengths at the time of installation. Please call for a quote and references.