The cryogenic liquid nitrogen mass flowmeter is developed for measuring the mass of cryogenic liquid nitrogen. The flowmeter consists of mass flow sensor and transmitter. The sensor has the advantages of high precision, wide range ratio and high reliability. High efficient heat insulation technology is used to effectively control the heat exchange between liquid nitrogen and other low-temperature media when it flows through the sensor, so as to reduce the gasification of low-temperature medium such as liquid nitrogen in the pipeline, so as to reduce the influence of gasification on flow measurement. The digital signal processor (DSP) is used to process the collected signal, which has the functions of judging the real-time state of medium and other intelligent self diagnosis functions.
A multi variable system is used. The signal filtering is strengthened, the sensitivity and accuracy of signal measurement are greatly improved, the response time of the system is accelerated, and the measurement is more reliable.
The application of multivariable digital processing system makes the system composition more flexible and convenient. In many cases, the flow rate measurement system can not be configured with a digital converter.
The measurement accuracy is high, the mass flow measurement accuracy can reach 0.1% - 0.2%, the density measurement resolution can reach 0.002-0.02 g / cm ^ 3, and the temperature measurement error is less than 0.5 degree.
The density and temperature measurement function is realized, and the medium concentration measurement function (two-component medium) can be derived.