Data system calibration

For making valid engineering measurements, the most important consideration is how the transducer operates in the actual test environment with all signal conditioning attached. Although not always feasible, the transducer should be calibrated while connected to the same signal conditioning equipment in the laboratory as will be used on the actual test article. After mounting the transducer on the test article, perform a minimum of a data system calibration. This can be accomplished by simulating an excitation of the transducer such as is often accomplished for strain gages by using a shunt calibration resistor to simulate a change in resistance of the strain gage. In addition, inserting a simulated transducer signal into the system verifies all signal conditioning transfer function predictions. This calibration simulates transducer excitation by its physical input. Installation constraints (e.g. the transducer is inaccessible or glued onto a structure such as a strain gage) often mean that a data system calibration is the best that an instrumentation engineer can do to ensure acquisition of valid data. Data system calibration simulates the desired measured rather than physically stimulating the transducer sensing device