空气中双称量法砝码体积测量方法的研究

Research on Volume Determination Method of Double Weighing in Air

利用被测砝码和参考砝码在2种不同密度的空气介质中比较称量时,砝码间的质量差与空气密度差成线性变化这一特性,通过最小二乘法拟合质量差随空气密度差变化的曲线,提出了空气中双称量法砝码体积测量方法。基于空气中双称量法砝码体积测量数学模型和测量装置工作原理,分析影响测量结果的3个主要因素:2次测量的大气压变化范围,砝码表面解吸作用和质量比较仪计量特性。以10 g^1 kg OIML不锈钢砝码为例,将该方法测得的体积与液体静力比较法的测量结果比对,E n值评定结果小于1。

To study the linear change of mass difference and air density difference under two different air densities when comparing the test weight and reference weight,the least square method is used to fit the curve of mass difference and air density difference,and the double weighing in air volume determination method is proposed.Based on the mathematical model and the working principle of the measuring device,three main factors affecting the results are analyzed:the range of atmospheric pressure,the desorption of the weight surface and the mass comparator.Taking the 10 g^1 kg OIML stainless steel weight as an example,the volume determined by this method is compared with the result of the hydrostatic method,and the normalized error E n is less than one.