overview
The MEMS gas mass flowmeter is an intelligent all-electronic gas mass flow meter developed by the company using micro-electromechanical system (MEMS) flow sensor chip technology and computer adaptive technology. The main technical performance is at the international leading level. High sensitivity, high precision, and large range ratio. For industrial environments, MEMS gas mass flowmeters incorporate a variety of electromagnetic compatibility design with anti-jamming measures, and have a variety of signal outputs, enabling network management functions through communication interfaces: this product also has its performance, installation and maintenance. Unique advantages, can be widely used in petroleum, gas, chemical, smelting, energy and other fields.
Product features
■With the microelectromechanical system chip processing technology, large-scale integrated circuit production technology and material processing technology, the size of the sensor is reduced to the micron level, so that the sensitivity of the flowmeter is greatly improved.
■Multi-sensor integration is realized on a single chip, which greatly improves the range ratio of the flowmeter.
■Combined with the microcomputer intelligent technology of the secondary instrument, the flow meter has better repeatability and realizes accurate and reliable measurement.
■The structure simplification brought by the technical progress makes the flowmeter greatly reduce the pressure loss and reduce the energy consumption compared with the traditional mechanical instrument.
■LCD display instantaneous flow and cumulative flow, clear and intuitive, easy to read.
■Product integration of electromagnetic compatibility design technology, with high anti - interference ability.
■The flow meter with RS485 communication module, with the upper computer network can achieve centralized management.
■Optional 4~20mA standard current signal output.
■Some products have passed the national explosion-proof certification, marked as Ex ia llC, ExdllCT4.
Measuring principle
Microelectromechanical system (MEMS) sensing technology, the chip is integrated on the silicon chip has mechanical and electrical characteristics of micron level sensor, it is not simply to miniature mechanical and electrical function on a chip, but only made with modern materials technology and large scale integrated circuit technology for the combination of new mechanical and electrical characteristics of MEMS chip can obtain some macro mechanical and electrical device cannot reach.
At the same time, due to the use of multi-sensor and micro-heat source technology, it has excellent zero point stability, short response time and large range and other characteristics.
LKM blood series gas mass flowmeters are mainly composed of power supply module, MEMS flow sensor chip, signal processing module, A/D conversion module, EEPROM memory, PTC real-time clock module and display module, as shown in the flow meter principle block diagram (figure 1).
LKM is made by using the heat transfer effect of flowing fluid to change the temperature distribution of measured capillary wall.
The mass flow rate of the gas can be measured by using the principle of capillary heat transfer and temperature difference calorimetry, which is not affected by the temperature and pressure in a certain range. The expected value of the flow rate measured by the sensor is equal to that determined by the flow detection. The diverter generates a stable laminar flow state between the main channel and the capillary to adjust the flow rate through the flow controller.
