The Piston Type Verification Device For Heat Meters

As one of the important measurement instruments in urban heating supply trade settlement, the quality and related verification technologies of heat meters play an important role in the reform of implementation of fees based on household heating system. Although the heat meters’ calibration technology gets greatly development in recent years, because of the heat metering supply started late domestically, relevant technology is still lagging behind relative abroad. The calibration device with quality combined with standard meter method has been difficult to adapt to the development of heat meter industry as a result of the inefficient calibration and low accuracy.On the basis of existing verification technology for heat meters, a kind of dynamic verification technology based on piston structure is presented in this article. An automatic verification system based on Advantech IPC is designed, which completes the automatic data acquisition and process control in the VC++environment. Total test and component combination test are completed for heat meters.For the calibration device of hot water flow, a closed-loop control system for hot water circulation is designed which is made up of piston structure, servo motor and grating scale and so on. It can collect multi-channel analog signals, such as pressure, temperature and humidity by the advantech data acquisition modules, and control the hot water line valves by the advantech I/O control modules; For the verification device of temperature sensor pair and calculator, the system can achieve the standard temperature measurement by six half digital versatile multi-meters with its API functions and SCPI commands; Collection modules based on ARM Cortex-M3microprocessor are designed to accomplish the collection of pulse output signal of the grating scale and checked heat meters. At the same time, the hot water volume flow and uncertainty evaluation methods of pairing temperature sensor are also discussed in this article.The piston structure is used in the auto-detecting system, which has absorbed the advantages of the existing verification system, it is shown that this system can effectively improve the precision and efficiency of the heat meter verification, and there is practical importance for domestic heat metering reform and development of heat meter calibration technology.