Automatic Verification System Design And Implementation Of Fuel Dispensers

Fuel dispensers is the most important measuring instruments in the refined oilcirculation trade settlement, it’s level of accuracy as high as0.3%.In order to ensurethe accurate metering of oil, fuel dispensers verification work is particularlyimportant. The domestic institution of metrological technology adopted staticvolumetric method of fuel dispensers verification indication error, namely thestandard metal measurer for fuel dispensers verification standard device. Standardmetal tank standard device for the original method capacity measurement standards,accuracy is high, the maximum permissible error less than0.05%. Standard metaltank capacity calculation depends mainly on the measurement of cervical liquid leveland standard metal tank temperature, the measurement of liquid level andtemperature value of neck measurement by manual reading measurement neck scaleand a thermometer manner, caused by human factors and verification workunreliable, inaccurate. In order to solve this problem, be badly in need of a higherdegree of automation of the fuel dispenser verification device design and creation.This paper proposes the use of a sensor and MCU technology fuel to cheer machineautomatic test system design and implementation, the system uses embeddedplatinum resistance thermometer of magnetostrictive liquid level sensor in automaticacquisition of standard metal tank oil level height and temperature value, the outputof the analog signal by SCM signal is converted to a digital signal, and the throughthe MCU program capacity calculation model and temperature compensationcalculated actual temperature standard metal tank oil capacity, and with a fueldispensers indication is compared, the calculated error of indication of fuel fillingmachine.The system is mainly composed of standard metal tank, magnetostrictive liquidlevel sensor, a platinum resistance thermometer, data acquisition system, systemmaximum allowable error is less than0.05%. By calculation we choose100L two standard metal tank as the main standard, the maximum permissible error less than0.025%, far more than the fuel dispensers verification standard maximumpermissible error of0.05%requirements, at the same time, the structure design andmanufacture of full compliance with the fuel dispensers verification standardrequirements. Magnetostrictive liquid level sensor based on magnetostrictiveprinciple is the manufacture of high precision, long range linear, absolute positionmeasurement of liquid level sensor, the circuit is simple, with explosion-proofperformance, good environmental adaptability, reliability and stability, and the use ofnon-contact measurement methods, solve due to friction, wear caused by the lowservice life the problem, its design resolution up to0.1mm. Temperaturemeasurement using embedded in the magnetostrictive level meter level magneticscale two platinum resistance thermometer, accurate measurement refueling gun oiloutlet temperature and oil in the standard metal tank the temperature, the designpoints of the value of up to0.1degrees C, higher than0.2degrees C-valuerequirements. Through the signal transmission line level signals and temperaturesignals are output to the use of single chip microcomputer principle design of datacollector in the height of the liquid level and temperature signal acquisition andcalculation, the data collector power supply convenient manner, using12864LCD asa display interface, while the design of user-friendly interface, with the hostcomputer communication function, its compact and lightweight, the northeasternregion for outdoor use, a great convenience to the practical work.The system of measuring performance testing by laboratory calibration andalignment, through laboratory of higher level measurement traceability, its length,temperature, volume measurement indicators to get a reliable calibration, themeasurement indicators can be traceable to national measurement standards, toensure that the use of various measuring instruments are reliable the traceabilitysystem. The whole measurement system performance verification through andstability of the measurement standards of value comparison manner, in accordancewith the relevant procedures on fuel gas automatic calibration system a comparison test, the results of data processing through En to confirm, and the whole system ofcomprehensive evaluation of the uncertainty of measurement to judge whether itsatisfies practical need.The system through the data acquisition sensor output values of the correctionand calculation, mainly through the laboratory calibration on the level, thetemperature value, standard metal tank capacity value, zero measuring carotiddivision value to adjust and amend, ensuring that each sensor accuracy level andcomputational results are precise and reliable.The system structure and signal processing design concept can also be furtherupgraded. The fuel filling machine of automatic verification system using sensorprocessing transformation, thermal insulation performance enhancement, to bubblefunction improvement, data collector can be further upgraded, the structure ofsystem and main measurement performance was perfect, form a completetechnology solutions and product evaluation program, and then through the newproduct type evaluation, to to make the system truly into the market product, makethe project in the oil fuel filling machine testing areas play a major role, reducing thelabor intensity of workers, improves the work efficiency.