Development Of Mobile Online Calibration System For Water Meter

As the tool for measuring water flow, water meter supplies thereference basis for water management authority both in collection of waterbills and scheduling management. With the shortage of water resourcesbecoming more and more prominent, the accurate measurement of watermeter is more important. Usually, the water meters are dismounted from thepipelines and delivered to metrological department for offline verification orcalibration in their calibration facility. However, many of the water meters inenterprise used for trade settlement are difficult to remove or not allowed tocutoff. Moreover, the measuring accuracy of water meter in industrial site isnot only effected by itself features, but also by the field conditions. So theonline calibration can reflect the error level of water meter under daily use,and the judgment of the water meter performance has more realisticsignificance.According to JJG162-2009Verification Regulation of Cold WaterMeter, a set of mobile online calibration device of water meter is designed inthis paper, the main research results are as follows:1. A set of mobile online calibration device of water meter is constructed.The portable ultrasonic flowmeter is chosen as the standard meter, the preciselocation and installation of its transducer probe can be completed byaccurately measuring the pipe wall thickness using thickness gauge. Thepulses produced by the water meter pointer are acquired by digital lasersensor. The industry control computer on the handbarrow acquires pulsesthrough the data acquisition card, and acquires the flow of the standard meterthrough the serial port. The calibration is carried out using the standard metermethod.2. According to the verification regulation, the standard meter iscalibrated. Taking the standard tank as standard calibration device, a calibration system is constructed. The programming of the calibration ofultrasonic meter is designed based on LabVIEW software platform. Manyfactors have influence on the performance of ultrasonic flowmeter areanalyzed, and the experiments of related parameters setting are carried out.3. The calibrated ultrasonic flowmeter is used in the mobile onlinecalibration device for water meter. The programming of the mobile onlinecalibration system for water meter is designed. The data acquiring,processing, report generation and data storage are achieved.4. Communication between the industrial control computer and remotemonitoring computer is realized using wireless network. Through the functionof web publishing in LabVIEW, remote users can access the front panel. Theremote monitoring of field condition is realized using a wireless networkcamera, realizing the round-the-clock unattended remote measurement.Analysis and evaluation of the uncertainty of measurement of this deviceare carried out. The result meets the expected design requirements. Themobile online calibration device is simple to install in field, and the userinterface program is intuitive convenient. This device preferably realizes theonline calibration of water meter.