Development Of Calibration Equipment For Dust Measurement Device

Dust concentration meter is a measurement instrument used for monitoring dust concentration in environmental monitoring and occupational health protection.Its measurement data is an important basis for air environment governance.Whether the data is accurate will have an impact on the government’s formulation of environmental governance policies.Because each instrument measurement principle is different,and different manufacturers of factory verification procedures are different,different measurement results between different instruments,values cannot be unified,most of the domestic measurement verification mechanism is simply flow verification or calibration,for the main concentration index can not achieve traceability,so it is urgent to meet the traceability requirements of dust concentration meter calibration device.Taking the calibration device of dust concentration meter as the research object,this paper discusses the principle and development background of dust concentration meter and calibration device,and lays a theoretical foundation through the research status.By studying the working principle of the calibration device of the dust concentration measuring instrument and combined with the actual working situation,the overall design scheme of the calibration device is determined,that is,the weight method and the reference dust meter comparison method are used to trace the source of the tested instrument.In order to enable the device to simulate the dust environment in different scenes,the dust generating device is designed to emit different dust sources,While meeting the traceability requirements of dust concentration measuring instrument,it is also necessary to improve the performance of the device and strengthen the practicability of the device.According to this design idea,this paper designs the hardware system of the calibration device,completes the selection of the main components of the calibration device and the construction of the device,and completes the development of the control system of the calibration device,so that it can realize the functions of automatic control of dust concentration,real-time data acquisition and so on.After the successful development of the device,a large number of experiments have been carried out.Through experimental verification,the device meets the technical requirements of JJG846-2015《verification regulation of dust concentration measuring instrument》.Through uncertainty analysis and verification,the device can trace the source of dust concentration measuring instrument with range of(0～50)mg/m~3.The calibration device developed in this paper has the following innovations:1.The dust generating device adopts Wright principle,and different kinds of particles can be generated by replacing the dust pipe,so as to adapt to the verification,calibration and detection of dust concentration measuring instruments in different places.2.The device also innovates the mixing mode of dust particles based on the principle of centrifugal force,so as to improve the uniformity and stability of the device,which are less than 5%.3.The dust concentration of the calibration device can be controlled automatically.