Ultrasonic heat meter technical indicators and parameters 1, ultrasound is not a very recent high technology, early in World War II it was used in the war against the Allies in Germany, to explore submarine submerged submarine. In comparison, Wiegand technology to produce in 1974, the United States, non-magnetic detection technology produced in 1987 in Germany, especially in the medical field are widely used in civilian. 2, ultrasound used in the calorimeter using a "differential method" to measure the flow. Specific principle is: When the ultrasonic flow of water with water will produce a time, compared with the normal speed, it will produce a time difference, using the time difference to calculate the flow rate of the water, and then multiplied by the diameter of the flow rate, it has been traffic. So the "differential method." This method requires strict timing control, general ultrasound propagation speed in water is 1500 m / s, the timing control circuit should be calculated MCU cycles, usually 10-12 seconds, milliseconds to less than a slight deviation will affect the measurement. 3, the ultrasonic transducer requires high precision, it has an aluminum titanate-zirconate piezoelectric material, i.e., the sound of the wedge that is close to the number of words transmitted plexiglass a composition required to have high strength, toughness prison, anti-aging. Currently, the international transducer import price of a pair of 600 yuan or so, the price is too high, and low domestic prices and no quality assurance, and quality of imported products are not comparable. 4, ultrasonic heat meter afraid impurities in the water, because the water impurities offset angle of incidence of the ultrasound, affect the accuracy of measurement. So now afraid of publicity ultrasonic heat meter block, this is beyond reproach, because it is close to a straight pipe state, but impurities in the water will affect the ultrasonic transducer, which is not mentioned manufacturers mislead users, impurities affect the water of a real problem metering. 5, ultrasonic heat meter afraid of bubbles in the water, because the water ultrasonic propagation velocity is about 1500 m / s, while the propagation speed in the air is 330 m / s, our heating network, after all, is not the manufacturer of the detection stage, using pure water, no bubbles, and heating pipe network is not possible free of impurities, bubbles, etc., and the propagation speed in the water and in the air, there will be close to five times the measurement errors.