基于活塞式压力计和数字压力计的微小压力测量新方法

摘要

提出了一种微小表压力(差压)测量的新方法.采用1台活塞式压力计和1台精密的数字压力计,通过关断阀连接高低压端的特殊连接方式实现微小表压力(差压)测量,解决了活塞式压力计由于受其下限值的限制而不能实现微小压力测量的问题.利用数字压力计较好的短期稳定性以及活塞式压力计较低的不确定度,可以实现1～ 10 kPa微小表压(差压)的校准,其校准结果的扩展不确定度为U=2.2 Pa(k=2).%A method for measuring the low differential or gauge pressure with the combination of a piston gauge (PG) , a digital pressure gauge (DPG) and a special connected way of a bypass is described. The problem of the lower pressure limit due to the load mass of the piston itself is solved. By the advantage of perfect short-term stability of the DPG and the lower uncertainty of the PG, the differential pressure or gauge pressure up to 10 kPa could be measured, the expanded uncertainty of the measurement is 2. 2 Pa with k = 2.