Vacuum Gauge Testers, Comparison Test Pumps for Pressure, Comparison Test Pumps for Vacuum and Master Dial Pressure Vacuum Gauges. Calibration is done against Master Dead Weight Pressure Gauge Tester and Master Dial Pressure Vacuum Gauges. Our instruments are backed by test certificates traceable to National Standards to meet the requirements of ISO 9000, QS 14000 and other Inspection Agencies. All our Master instruments including Dead Weight Tester and Master Gauges are certified and characterized by National Physical Laboratary, New Delhi