| 摘要 |
The present invention provides a difference measurement circuit (60) comprising a first port (P1, P1') and a second port (P2, P2') for connection to a first set of nodes (A, B) and a second set of nodes (C, D) of a sensor unit. The circuit (60) further comprises switching units (61, 62) for switching excitation signals emanating from excitation nodes (C', D') from being applied to the first set of nodes (A, B) via the first port (P1, P1') to being applied to the second set of nodes (C, D) via the second port (P2, P2') and for switching differential measurement signals measured at sensing nodes (A', B') from being obtained from the second set of nodes (C, D) via the second port (P2, P2') to being obtained from the first set of nodes (A, B) via the first port (P1, P1'). The present invention also provides a corresponding method. The circuit (60) further comprises redundancy testing circuitry for evaluating the similarity or deviation between measurement signals obtained in different states of the switching units (61, 62). |
