FG5X-246绝对重力仪准确度测试

摘要

利用最新研制的一套弱力测试平台,对FG5X-246绝对重力仪观测值准确度指标进行了测试试验.通过弱力测试平台升降装置改变扰动质量体与测量点之间的距离,从而改变测量点处叠加的扰动引力场大小.通过比较FG5X-246绝对重力观测值变化量与理论扰动引力场变化量之间的差异,从而确定FG5X-246绝对重力观测值的准确度.测试结果显示当扰动质量体从1.8104m高度降到1.4099m高度时,外部扰动引力场变化了48.81 μ Gal (1Gal=1cm/s2),FG5X-246绝对重力仪感应到48.0 μ Gal的重力变化,FG5X-246绝对重力仪测量值与理论值之差为0.81 μ Gal.当扰动质量体从1.8104m降到1.0101m高度时,外部扰动引力场变化了-15.44 μ Gal,FG5X-246绝对重力仪感应到-16.20 μ Gal的重力变化,测量值与理论值之差为0.76 μ Gal.当扰动质量体从1.4099m降到1.0101m高度时,外部扰动引力场变化了-64.20 μ Gal,FG5X-246绝对重力仪感应到-64.25 μ Gal的重力变化,测量值与理论值之差为0.05 μ Gal.上述测量结果表明,此次FG5X-246绝对重力仪感应到外部引力变化的误差均不超过1 μ Gal,即其测量值准确度优于1 μ Gal.%The observation accuracy of the absolute gravimeter FG5X-246 is tested by using the weak force test platform.The disturbing gravity field, which is produced by changing the distance between the disturbing mass and the observation point,can be superposed on the background gravity field directly.It is measured that this gravity change using FG5X-246 absolute gravimeter and compared it with that of theoretical disturbing gravity field and then determined the accuracy of the absolute gravity observations.The test results show that when the height of the disturbing mass changes from 1.8104m to 1.4099m, the disturbing gravity field changes for 48.81 μGal (1Gal=1cm/s2), while FG5X-246 absolute gravimeter senses the gravity change of 48.0μGal, and the difference between the measurement value and the theoretical value is 0.81μGal.When the height changes from 1.8104m to 1.0101m, the disturbing gravity field changes for-15.44μGal, while FG5X-246 absolute gravimeter senses the gravity change of-16.20μGal, the difference of them is 0.76μGal.When the height changes from 1.4099m to 1.0101m, the disturbing gravity field changes for-64.20μGal, while FG5X-246 absolute gravimeter senses the gravity change of-64.25μGal, the difference of them is 0.05μGal.The results indicate that the FG5X-246 absolute gravimeter sensing external gravity change error is no more than 1 μ Gal, that is, the accuracy of the measured value is better than 1 μ Gal.