A precision twin-wire resistance-probe manometer has been developed for the purpose of measuring very low differential pressure. From the extensive performance tests conducted, it was found that the output voltage from the manometer is linearly proportional to the difference in pressure. Several ranges of calibration were made; the accuracy of the output depends upon the range and sensitivity setting of the manometer. For the range of 0-0.2 mm of water with a sensitivity setting of 1000 mVlmm, the accuracy of ±0.02 Pa (about ± 0. 002 mm of water) was achieved.
