LIQUID METERS, WATER METERS, HEAT QUANTITY METERS, FLOW METERS AND REMOTE METERING MECHANISMS THEREFOR, NAMELY, REMOTE COUNTERS, REMOTE TOTALIZERS, REMOTE DISPLAYS FOR VISUAL READ-OUTS, REMOTE READ-OUT UNITS FOR REMOTE METER READING; APPARATUS USED IN WATER WORKS AND SEWAGE TREATMENT PLANTS, NAMELY, MEASURING APPARATUS FOR MEASURING, CONTROLLING AND REGULATING FLOW-RATE, PRESSURE, PRESSURE-RATES AND LIQUID LEVEL AND ELECTRICAL APPARATUS FOR SWITCHING PUMPS AND PARTS THEREFOR MADE FROM PLASTIC...