9 ELECTRICAL TESTING EQUIPMENT-NAMELY, A.C. AND D.C. METERS FOR TESTING AND CHECKING ELECTRICAL METERS, ELECTRICAL DEVICES, AND THE LIKE, ELECTRICAL TACHOMETERS, PYROMETERS, ORIFICE METERS, ORIFICE WELL TESTERS, CHART DRIVES AND RECORDERS, PRESSURE ELEMENTS-NAMELY, TUBING, DIAPHRAGMS, BELLOWS, BOURDON TUBES, AND THE LIKE, THERMOWELLS, HELICAL BOURDON TUBES, LEVELLING SADDLES, AND COMPONENTS FOR THE FOREGOING