초록 ▼

A method and apparatus for correction of null or zero reference offset error occurring in a measuring or transducing device by reason of temperature change, component ageing or other effects. A system including an appropriately programmed microcomputer, an analog-to-digital converter, a digital-to-a

A method and apparatus for correction of null or zero reference offset error occurring in a measuring or transducing device by reason of temperature change, component ageing or other effects. A system including an appropriately programmed microcomputer, an analog-to-digital converter, a digital-to-analog converter and an operational amplifier provides a closed feedback correction loop, controlled by the microcomputer, which can maintain the zero adjustment of an analog transducer and amplifier circuitry over an indefinite period of time.

대표청구항 ▼

Apparatus for compensating for drift from a null point of a measuring device comprising: comparison means for comparing a first signal from said measuring device with a derived second signal and for providing an output signal representative of the difference between said first and second signals; an

Apparatus for compensating for drift from a null point of a measuring device comprising: comparison means for comparing a first signal from said measuring device with a derived second signal and for providing an output signal representative of the difference between said first and second signals; analog-to-digital converter means to which said output signal is applied, for providing a digital equivalent of said output signal; digital-to-analog converter means for providing said second signal to said comparison means; and data processing means coupled to said analog-to-digital converter means and to said digital-to-analog converter means, and operable in an iterative operation to generate a compensating value which, when applied to said digital-to-analog converter means, results in said second signal having a predetermined relationship to said first signal, said compensating value being generated in a plurality of iterations commencing from a predetermined initial value by incrementing said digital-to-analog converter means to change the magnitude of said second signal until said output signal applied to said analog-to-digital converter means by said comparison means attains a predetermined value.