26 MANUAL, AUTOMATIC, PNEUMATIC, ELECTRIC AND ELECTRONIC GAGING APPARATUS; DIMENSIONAL COMPARATORS; ANALOG TO DIGITAL CONVERTERS; DATA REDUCTION DEVICES; PROCESS MEASURING AND CONTROL EQUIPMENT; SORTING DEVICES; RECORDERS; APPARATUS FOR MEASURING PROPORTION, LIQUID FLOW, LIQUID LEVEL, TEMPERATURE, PRESSURE, HARDNESS, TENSILE STRENGTH, DURABILITY, DENSITY, AND DISTANCE; AND SIGNAL TRANSMITTERS AND TRANSDUCERS USED IN ASSOCIATION WITH THE ABOVE DEVICES AND TEST APPARATUS FOR CALIBRATING GAGING DEVICES