A large etching system for plastic track detectors

A large scale etching system has been developed for the track detector array being used in a magnetic monopole search. The system consists of two etching tanks, a reservoir, a waste etchant tank, a dyeing bath and a water bath. The precisely controlled huge etching tank makes it possible to regulate the etchant temperature to within ± 0.01oC at 90oC and to etch 320 plates of CR-39 each with dimensions 54 cm x 56 cm x 1.6 mm, at once. The efficient temperature control and a moderate circulation of the etchant ensure uniform etching for all the plastic sheets. Details of the etching system and operation are described. (author)