Differential pressure measurement is of increasing importance for many industrial applications, for example in oil and gas industry, as well as in the medical application such as the differential pressure application in the ventilator and ventilator tester. The demands of accuracy in differential pressure measurement are increasing as well through the traceability chain into the primary standard. In this study, two differential pressure calibration methods have been successfully implemented in the “Standar Nasional Satuan Ukuran-Badan Standardisasi Nasional (SNSU-BSN)” as the national metrology institute of Indonesia to calibrate the differential pressure of the ventilator tester. The first method is by generating the differential pressure reference value from two pressure balances and the second one is by using a single pressure balance with the aid of air reservoir, precise digital pressure monitor, and the iterative A-B-A-B-A methods from the previous study. Both methods measurement results show good agreement by each other with the Normalized Error less than 1.0 from 0 to 100 mbar. The major uncertainty contributions in both methods came from the hysteresis of the DUT. However, the expanded uncertainty in single pressure balance method is larger than the double pressure balance method due to the instability of the pressure line that affects the variation of DUT indication. It can be concluded that either two pressure balances or single pressure balance can be used by the laboratory for differential pressure calibration, regardless by considering the available facility and the ease of performing the calibration.

压差测量对于许多工业应用越来越重要，例如在石油和天然气工业以及医疗应用中，例如呼吸机和呼吸机测试仪中的压差应用。通过可追溯性链到主要标准，对差压测量精度的要求也在增加。本次研究中，印度尼西亚国家计量院“Standar Nasional Satuan Ukuran-Badan Standardisasi Nasional (SNSU-BSN)”成功实施了两种差压校准方法，用于校准呼吸机测试仪的差压。第一种方法是通过从两个压力平衡中生成压差参考值，第二种方法是在储气罐、精确数字压力监测器和先前研究中的迭代 ABABA 方法的帮助下使用单个压力平衡。两种方法的测量结果都显示出良好的一致性，从 0 到 100 毫巴的归一化误差小于 1.0。两种方法中的主要不确定性贡献来自 DUT 的滞后。然而，由于压力线的不稳定性影响了DUT示值的变化，单压力平衡法的扩展不确定度大于双压力平衡法。可以得出结论，实验室可以使用两个压力天平或单个压力天平进行差压校准，