Method and apparatus for controlling zero adjustment of weight sensor

A method of controlling the zero adjustment of weight sensors in a combinatorial scale of the type which is adapted to measure, by means of said weight sensors which are provided on a plurality of respective weighing hoppers, the weight of articles introduced into said plurality of weighing hoppers, and selecting the combination or articles that gives a total weight closest to a set target weight, and discharging from the weighing hoppers the articles in said selected combination, said method comprising the steps of:

• counting a number of times the articles are discharged from each weighing hopper;
• discriminating whether each said discharge counted value has attained a first predetermined value;
• delivering a zero point deviation of the weight sensor provided on that weighing hopper for which said discharge counted value, which indicates the number of times the articles have been discharged therefrom, has attained said first prdetermined value;
• discriminating whether the zero point deviation of said weight sensor lies within preset allowed limits;
• applying a zero adjustment to said weight sensor when the zero point deviation thereof lies within said allowed limits and generating a signal for inhibiting the zero adjustment when said zero point deviation lies outside of said allowed limits;
• counting a number of times the zero adjustment inhibit signal is generated;
• and
• comparing said inhibit counted value with a second predetermined value to produce an alarm signal when said inhibit counted value and second predetermined value coincide.

An apparatus for controlling a zero adjustment of weight sensors for measuring the weight of articles, comprising:

• zero adjusting means for applying a zero adjustment to each weight sensor;
• discriminating means for discriminating whether the zero point deviation of said each weight sensor lies within preset allowed limits;
• means for causing said zero adjusting means to apply a zero adjustment to said each weight sensor when the zero point deviation thereof lies within said allowed limits and for generating a zero adjustment inhibit signal for inhibiting the zero adjustment when said zero point deviation lies outside of said allowed limits;
• counting means for counting a number of times the zero adjustment inhibit signal is generated;
• and
• comparison means for comparing the counted value with a predetermined value to produce an alarm signal when said counted value and predetermined value coincide.

An apparatus for controlling the zero adjustment of weight sensors in a combinatorial scale of the type for measuring, by means of said weight sensors which are provided on a plurality of respective weighing hoppers, the weight of articles introduced into said plurality of weighing hoppers, selecting the combination of articles that gives a total weight closest to a set target weight, and discharging from the weighing hoppers the articles in said selected combination, said apparatus comprising:

• zero adjusting means for applying a zero adjustment to each weight sensor;
• first counting means, provided for each weighing hopper, for counting a number of times the articles are discharged from said weighing hopper;
• first comparison means for discriminating whether said discharge counted value provided by said first counting means has attained a first predetermined value;
• selection means for selecting, when said counted value has attained said first predetermined value, the zero point deviation of the weight sensor provided on that weighing hopper which corresponds to the first counting means whose output is said discharge counted value;
• discriminating means for discriminating whether the selected zero point deviation lies within preset allowed limits;
• means for causing said zero adjusting means to apply a zero adjustment to said weight sensor when the zero point deviation thereof lies within said allowed limits and for generating a signal for inhibiting the zero adjustment when said zero point deviation lies outside of said allowed limits;
• counting means for counting the number of times the zero adjustment inhibit signal is generated;
• and
• second comparison means for comparing the said inhibit counted value with a second predetermined value to produce an alarm signal when said inhibit counted value and second predetermined value coincide.