The Significance and Value of Performing Calibrations
To perform a calibration is to compare measurement values of a flowmeter with another standard measuring device and adjust accordingly.
At our company, we mainly calibrate turbine flowmeters that read aircraft fuel and oil measurements, but the flowmeters that are used in aircrafts require an extremely high level of precision. One mistake in the adjustments could lead to a major accident if the flowmeter could not tell when the aircraft was out of fuel.
Our company is the only company in Japan handling flowmeters for aircraft that has been certified by COX Instruments (America), a company with a long history of high performance that is trusted around the word. As a result, we maintain an environment in which we can invite technicians over from COX Instruments for training sessions to improve our technical know-how and share information about products. The strict calibration guarantees traceability, which adds ‘trust’ to the high-quality flowmeters produced by COX Instruments and other large manufacturers.
The Technology Needed for Calibrations
The Accuracy of Adjustments in Liquid Temperature
One of the points that requires ‘technical expertise’ in calibration is the accuracy of liquid temperature adjustment. The density and viscosity of liquid changes with temperature, and so it is possible that the readings (data) on the flowmeter may change with temperature. So as to prevent mistakes occurring, the temperature must be carefully controlled in the same environment as which it is normally measured. This is where technology makes a difference.
Calibration of Master Meters
We often receive requests from our customers with the goal of calibrating using the master meter flowmeter which is used as the company standard. Normal flowmeters are calibrated using liquid with one type of viscosity, but master meters, which require a greater level of precision, are calibrated using liquid with several types blended together or used one after the other.
Calibration of Dual-rotor Flowmeters
Not only do we calibrate single-rotor turbine flowmeters (with one impeller), we also perform calibrations on the duel-rotor flowmeters (with two impellers) developed by COX Instruments. Many of these cases involve not only calibrating the dual-rotor flowmeter, which boasts advantages such as reliability, a broader measuring range and smaller installation space, but also the flow computer. High-precision technology is required to simultaneously measure the output from each impeller and manipulate the various functions added to the flow computer.
Calibration Equipment and Manual Operation
Our company uses a piston prover (a piece of calibration equipment that measures the flow of liquid pushed out of a piston by calculating the time and volume) manufactured by FLOW DYNAMICS to perform appropriate markups. The piston prover manufactured by FLOW DYNAMICS is a reliable piece of equipment that is used in American National Institute of Standards and Technology (NIST). FLOW DYNAMICS is a company affiliated with COX Instruments whose calibration equipment is known for its history, performance and high precision. Our company possesses two piston provers, one to measure small flows and another to measure large flows.
You may think that manual operation is only involved when attaching flowmeters to the calibrating equipment, but there are actually many instances in which our staff are able to demonstrate their expertise, from flowmeter investigation, to the preparation (and handling) of equipment and liquid, collecting data, and creating reports. By combining the measurement precision of our equipment and the accurate judgements and detailed adjustments made by our staff, we are able to provide ‘flawless calibration’ to meet our customers’ demands.