The process of adjusting the output on a measurement instrument to recognize the value of the applied standard, within a nominated accuracy, is called calibration. Any kind of process instrumentation requires periodic calibration and maintenance to ensure that it is operating essentially. Calibration is necessary in the marine industry to obtain traceability, to satisfy safety requirements, to save energy, to reduce pollution, to achieve optimum machine operation and efficiency, to unexpected repair and replacement and to prevent turn-down of machinery. There are unique kinds of systems in marine equipment which require calibration. Hence, different kinds of calibrators are used. Pressure Calibrator is a tool used for generating pressure for testing, adjusting and calibration of any mechanical or electronic pressure-measuring instrument by way of comparing. Pressure is generated by the pressure calibrator at a desired value and the device under test is compared together with a reference instrument/test gauge to look for the accuracy. An adjustment or calibration can be carried out by comparison of the two measured values. In the marine industry, the pressure calibrator is used for calibration of pressure gauge, pressure transmitter, pressure switch etc. A milliamp calibrator sources and measures the loop DC current. It works to calibrate recorders, digital indicators, stroke valves or every other instrument that get their dream like input from a 4 to 20 mA loop. A milliamp calibrator combines 0 to 24 mA source, mA Meter, 2-wire Transmitter Simulator & DC Volt Meter a single unit. The display on the milliamp calibrator indicates error codes and visual warnings for loop mismatch, reverse polarity and over scale. A multifunction calibrator is an accurate, flexible instrument that permits the calibration numerous different types and models of electrical testers efficiently and effectively. It can be used to calibrate bench and handheld multi-meters, frequency meters, ohm meters, voltmeters, thermocouple indicators, clamp meters, temperature indicators, timer counters, oscilloscopes and a lot other measurement aids. Multifunction calibrators are used in marine industry for calibration of thermocouple for stern tube bearings, turbine and gear bearings, ventilation, cooling and refrigeration equipment, etc. Other requirements each morning marine industry are for calibration of turbo-charger lubrication systems, cylinder or fuel valve cooling media which help in fuel oil inlet and scavenging of air, exhaust gas controls, sea water cooling equipment, crankcase protection, servo oil pitch propellers, cooling water outlets, purifiers, refrigeration systems, hydraulic systems, condensing systems, oil burners, generators and safety valves.