This part of IEC 61298 specifies general methods and procedures for conducting tests and reporting on the functional and performance characteristics of process instrumentation except Process Measurement Transmitters (PMT) which are standardized by IEC series 62828. The tests are applicable to any such devices characterized by their own specific input and output variables, and by the specific relationship (transfer function) between the inputs and outputs, and include analogue and digital devices. For devices that require special tests, this standard should be used, together with any product-specific standard specifying special tests. This standard covers tests for the effects of influence quantities.