3. 4.3 Responses of measuring system to typical excitations u Both the transfer function and the frequency response function describe the response of a measuring instrument or system to sinusoidal excitation u But the frequency response describes only the transfer characteristics of a system with steady-state input and output Ua transient output will reduce gradually to zero, and the system will then reach the steady-state stage. For describing the whole process of the two stages, the transfer function must be employed. and the frequency response is only a special case of the transfer function❑Both the transfer function and the frequency response function describe the response of a measuring instrument or system to sinusoidal excitation. ❑But the frequency response describes only the transfer characteristics of a system with steady-state input and output. ❑A transient output will reduce gradually to zero, and the system will then reach the steady-state stage. For describing the whole process of the two stages, the transfer function must be employed, and the frequency response is only a special case of the transfer function. 3.4.3 Responses of measuring system to typical excitations