Abstract: Differential pressure noise is the difference between the real-time measurement differential pressure value and that of the truth or the average of the measurements. The traditional measurement takes the noise as the interference of the quantity being measured, and tries to eliminate or reduce it. While the modern measurement technique takes it as the information carrier of the measured quantity and it is most important in quantity measurement of two-phase flow. In this paper, the Rosemont 3051S intelligent differential pressure transmitter and the NI4350 data acquisition board were used to get the differential pressure noise through the LabVIEW data acquisition procedures when the water and gas-water two-phase flow passed through the orifice. The comparative analyses of the time-domain and spectrum of the differential pressure noise in water and gas-water two-phase flow were done. Study results show that the transmitter’s blockage fault can be effectively judged by the orifice plate differential pressure noise or its spectrum.