Measuring Amplifier with Background Adjustment and Method Therefor

摘要

The present invention relates to a measuring amplifier (103) with background calibration and adjustment, as well as to a method for carrying out the background calibration and adjustment for such a measuring amplifier. The measuring amplifier amplifies, digitizes and processes at least one measurement signal (111) from at least one measuring transducer (102) with the aid of at least one amplifier arrangement (108). This can be intermittently replaced by an additional amplifier arrangement (107), which enables its interruption-free calibration and, if necessary, adjustment. In the calibration, both a zero point error as well as an amplification error of the amplifier arrangement are reliably determined. Moreover, the amplifier arrangement is calibrated directly and not indirectly. Thereby a high accuracy is achieved without measurement interruption. Furthermore, only one additional amplifier arrangement is generally required, even for a measuring amplifier with plural channels.

主权项

1. Method for interruption-free calibrating and adjusting of a measuring amplifier (103; 203; 303) for N measurement signals (111; 211, 225; 311, 325), which comprises at least N+1 amplifier arrangements (107, 108; 207, 208, 224; 307, 308, 324), and is configured for outputting N measurement values that correspond to the N measurement signals, whereby N≧1 pertains and for i=1 to N the following steps are carried out:
supplying (S1) an ith measurement signal of the N measurement signals to an ith amplifier arrangement of the at least N+1 amplifier arrangements; outputting (S2) measurement values produced by the ith amplifier arrangement from the ith measurement signal; supplying (S3) at least two ith reference signals (112, 113; 212, 213; 312, 313) to a further amplifier arrangement of the at least N+1 amplifier arrangements; calibrating (S4) the further amplifier arrangement with the aid of the at least two ith reference signals, whereby a zero point error and an amplification error of the further amplifier arrangement are determined; adjusting (S5) the further amplifier arrangement, when at least one of the errors determined for it lies above a prescribed threshold value for this error; supplying (S6) the ith measurement signal to the further amplifier arrangement; outputting (S7) measurement values produced by the further amplifier arrangement from the ith measurement signal; supplying (S8) at least two reference signals to the ith amplifier arrangement; calibrating (S9) the ith amplifier arrangement with the aid of the at least two reference signals, whereby a zero point error and an amplification error of the ith amplifier arrangement are determined; and adjusting (S10) the ith amplifier arrangement when at least one of the errors determined for it lies above the prescribed threshold value for this error.