Water Phantoms with Depth Positioning Assembly

The models WP-3040 and WP-3840 are water phantoms with convenient manual ion chamber depth positioning. The water tanks are constructed of 3/8" acrylic and provided with side mounted handles, a drain and a ball valve. The outstanding feature is the depth positioning assembly that is common to both models and is unique in construction and operation. The ion chamber holder Teflon block slides on two stainless steel rods and is driven by a brass lead screw. One turn of the hand crank quickly and accurately moves the chamber holder block 1mm. A mechanical counter with pushbutton reset capability indi-cates depth to the nearest 0.1mm. The chamber holder block has a 7mm hole with 3 set screws, designed to hold various chamber holders. The chamber holder that is supplied with the phantom can accommodate cylindrical ion chambers of various diameters, from 3mm to 20mm. Parallel plate ion chamber holders are available as an option to accommodate Markus or NACP chambers and Roos chambers. The horizontal off-center positioning is achieved by sliding the depth positioning assembly along the edge of the water tank to the desired position as indicated on the horizontal scale mounted on the side of the tank. The larger phantom features two scales. The depth positioning assembly of both models may be easily retro-fitted with an optional remote motor drive that allows chamber depth positioning from a remote location. The depth is indicated by a digital LCD display with push-button zeroing, adding convenience and significant time saving to your monthly routine.