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随着电子技术的发展,在国内外贸易中,使用由称重传感器特别是应变式传感器作为承载元件的电子衡器越来越多。这些称重传感器大多数在使用前用产生力值的仪器或机器进行校准,主要是各种力标准机:静重式、杠杆式、叠加式或液压式。当把称重传感器组装到衡器上后,虽然制造厂已经用标准砝码进行检定或校准过,但仍应根据具体使用地点对相应的衡器进行调整,以消除由于重力加速度值的不同所带来的附加误差。这些对于已使用电磁补偿称重传感器,并且用内置的调整砝码或外部的已校准精密砝码进行调整的高精度衡器不成问题。但从商业观点看使用内装调整砝码太贵,从法制计量观点看在衡器使用地一般不允许用户用外带砝码进行调整,只能由授予权的计量人员调整。因此,当衡器的制造地点和使用地点的地理纬度和海拔高度相差较大时,制造厂应根据二者差值引起的重力加速度值之差对衡器进行相应调整——称作重力加速度值调整。如果能够在全国范围内进行适当的重力区划分,衡器制造厂能据此对所制造的全部衡器进行预先调整,并在衡器铭牌上标出与预定使用地点的重力加速度值范围相对应的纬度和海拔高度的范围。这样不仅有利于制造厂对衡器的重力调整,也有利于使用者购买满足自己要求的衡器。同时使用者可以自由地在标出的纬度和海拔高度对应的地理区域内移动衡器,不必考虑其位置变化给称重值带来的附加误差。
With the development of electronic technology, more and more electronic weighing scales are used in the domestic and foreign trade by using load cells, especially strain sensors. Most of these load cells are calibrated with force-generating instruments or machines prior to use, mainly on a variety of force standard machines: static, leverage, overlay or hydraulic. When the load cell is assembled on the weighing scale, although the factory has been calibrated or calibrated with a standard weight, the corresponding weighing scale should be adjusted according to the specific place of use to eliminate the difference caused by the difference of the gravitational acceleration Additional error. These are no problem for high-precision scales that have been magnetically compensated with load cells and adjusted with a built-in adjustment weight or an externally calibrated precision weight. But from the commercial point of view the use of built-in adjustment weight is too expensive, from the legal point of view measurement does not allow the user to use the weight with the adjustment of the weight generally can only be adjusted by the authorized measurement staff. Therefore, when the difference between the geographical latitude and altitude of the place of manufacture and the place of use is large, the manufacturer shall adjust the weighing instrument according to the difference between the gravitational acceleration caused by the difference between the two - called gravity acceleration adjustment. If the appropriate gravitational division can be carried out across the country, the scale manufacturer can pre-adjust all the scales made and mark the scale nameplate with the latitude corresponding to the range of gravitational acceleration at the planned site of use and Range of altitude. This will not only help manufacturers adjust the weight of the weighing instrument, but also help users to buy to meet their own requirements of the weighing instrument. At the same time, the user is free to move the weighing instrument in the geographical area corresponding to the marked latitude and altitude without considering the additional error caused by the change of position to the weighing value.