The content of the invention
It is an object of the invention to provide a kind of flow sensor calibration method and system, for solve calibration efficiency it is low,The problem of error is big, uniformity is low.
It is an object of the present invention to provide a kind of flow sensor calibration method, this comprises the following steps：
S11, the flow-pressure differential detected using differential pressure pickup in corresponding pressure difference under multiple fluid flows, acquisition testing rangeCurve, the fluid flow is detected by flow sensor to be calibrated；
S12, testing range is segmented, flow-differential pressure curve is fitted respectively in multiple sectionalization test ranges, obtainedMultiple method of subsection simulation curve, determine calibration factor；The method of subsection simulation curve is once linear curve or quadratic linear curve.
Further, the S12 comprises the following steps：
S121, default error of fitting threshold value, carry out initial fragment to testing range, convection current are distinguished in multiple sectionalization test rangesAmount-differential pressure curve is fitted, and obtains multiple method of subsection simulation curve, and the method for subsection simulation curve is once linear curve or secondary lineLinearity curve；
S122, when the corresponding error of fitting of a certain flow meets or exceeds error of fitting threshold value on method of subsection simulation curve, from thisFlow position carries out re-segmenting to testing range, until corresponding be fitted of all flows is missed on method of subsection simulation curve in testing rangeDifference is less than error of fitting threshold value, determines calibration factor.
Further, the error of fitting threshold value is 5%.
Further, the error of fitting threshold value is 3%.
Further, the method that initial fragment is carried out to testing range is that testing range is equally divided into N sections, describedN is 2 to 20；Or,
Further, the method that initial fragment is carried out to testing range is that testing range is divided into N section, the N for 2 to20；Flow is got over hour, and section length is shorter.
Further, it is further comprising the steps of after the step S12：
S13, using calibration module by standard flow by certain flow by flow sensor, according to the flow value and reality of measurementThe flow value of calculating calculates compensating factor；The calibration module is that can produce the fluid generating apparatus of constant volume and flow.
Further, the flow sensor couples with PC calibration terminals, and the calibration method is further comprising the steps of：
S14, by PC calibration terminals by calibration factor and/or compensating factor value write diagnostics parameter, calibrated fluxes sensor justBeginning characterization data.
Further, the PC calibration terminals couple with flow controller, and the flow controller is used to control to pass through flowThe fluid flow of sensor.
Present invention also offers a kind of system for calibrating flow sensor, including flow sensor, the stream coupled by circuitAmount controller, differential pressure pickup and PC calibration terminals；The flow controller is used to control the fluid flow by flow sensor,The differential pressure pickup is used to detect the pressure difference produced by the fluid of flow sensor, and the PC calibration terminals for being by calibrationNumber and/or compensating factor value write diagnostics parameter, calibrate the data from initial characteristic.
The calibration method of inventive flow sensor, by carrying out segmentation plan to the flow-pressure differential curve in testing rangeClose, improve the accuracy of flow sensor calibration；The fluid parameter complicated without measurement and instrument parameter, improve calibrationEfficiency；Further calibrated by calibration module flow sensor so that different flow sensor stand so as to errorSmall, uniformity is high.
Embodiment
In order to make the purpose , technical scheme and advantage of the present invention be clearer, it is right below in conjunction with drawings and ExamplesThe present invention is further elaborated.
Fig. 1 is the system for calibrating flow sensor in first embodiment of the invention, should include the stream coupled by circuitQuantity sensor, flow controller, differential pressure pickup and PC calibration terminals；The flow controller is used to control to pass through flow sensorFluid flow, the differential pressure pickup is used to detect the pressure difference produced by the fluid of flow sensor, the PC calibration terminalsFor by calibration factor and/or compensating factor value write diagnostics parameter, the initial characteristic data of calibrated fluxes sensor.
Wherein, the PC calibration terminals in the present embodiment calibration system include control board, pass through the control electricity of PC calibration terminalsRoad plate, can set the fluid flow parameter of flow controller.
The system for calibrating flow sensor that the present embodiment is provided is simple in construction, easy to operate, the flow complicated without measurementSensor technology parameter is that the calibration of flow sensor can be achieved.
Further, as shown in Fig. 2 the system for calibrating flow sensor of the present embodiment also includes calibration module, the schoolQuasi-mode block can be the calibration cylinder with certain volume, pass standard flow by flow by certain flow using with calibration moduleSensor, so as to realize the further calibration of flow sensor progress.The calibration system of this programme is particularly suitable for use in manyIndividual flow sensor is calibrated, and can reduce the individual difference between different flow sensor.
Second embodiment of the invention provides a kind of calibration method of flow sensor, comprises the following steps：
S11, the flow-pressure differential detected using differential pressure pickup in corresponding pressure difference under multiple fluid flows, acquisition testing rangeCurve, the fluid flow is detected by flow sensor to be calibrated；
S12, testing range is segmented, flow-differential pressure curve is fitted respectively in multiple sectionalization test ranges, obtainedMultiple method of subsection simulation curve, determine calibration factor；The method of subsection simulation curve be once linear curve or quadratic linear curve, reallyDetermine sectional calibration coefficient.
Present embodiment to testing range by being segmented, to the flow-pressure differential curve in each sectionalization test rangeOnce linear fitting or secondary existing fitting are carried out respectively, it is and directly direct to the flow-pressure differential curve in testing rangeThe technical scheme for carrying out existing fitting is compared, and fitting result is more accurate so that flow sensor calibration error it is smaller,Accuracy is higher.
Further, the S12 comprises the following steps：
S121, default error of fitting threshold value, carry out initial fragment to testing range, convection current are distinguished in multiple sectionalization test rangesAmount-differential pressure curve is fitted, and obtains multiple method of subsection simulation curve, and the method for subsection simulation curve is once linear curve or secondary lineLinearity curve；
S122, when the corresponding error of fitting of a certain flow meets or exceeds error of fitting threshold value on method of subsection simulation curve, from thisFlow position carries out re-segmenting to testing range, until corresponding be fitted of all flows is missed on method of subsection simulation curve in testing rangeDifference is less than error of fitting threshold value, determines calibration factor.
This programme detects all flows on multiple method of subsection simulation curve by pre-setting error threshold by software pointwiseCorresponding error of fitting, by the control of error of fitting value below the error threshold pre-set, then determines method of subsection simulation curve；This programme further increases the accuracy of curve matching so as to flow compared with the technical scheme for being not provided with error thresholdThe error of pick up calibration is smaller.
Further, the error threshold is 5%.The error threshold scope of this programme can obtain more accurate flow and passSensor calibration result.
Further, the error threshold is 3%.Compared with a upper technical scheme, the calibration result of this programme is more accurateReally.
Can be that testing range is averaged it should be noted that having a variety of for the segmentation method to testing rangeSegmentation or non-average mark section.
In an embodiment of the present invention, the method that initial fragment is carried out to testing range is that testing range is equally divided into NSection, the N is 2 to 20.
Preferably, the method that initial fragment is carried out to testing range is that testing range is divided into N sections, the N is 2 to 20；Flow is got over hour, and flow is smaller, and section length is shorter.
Further, it is further comprising the steps of after the step S12：
S13, using calibration module by standard flow by certain flow by flow sensor, according to the flow value and reality of measurementThe flow value of calculating determines compensating factor；The calibration module is that can produce the fluid generating apparatus of constant volume and flow, exampleCalibration cylinder such as with certain volume.
Specifically, this programme can be in the testing range calibrated in flow sensor, according to the measurement stream of standard flowError between value and the actual flow value calculated, by average computation according to corresponding error under multiple fluid flows, reallyDetermine compensating factor, then flow sensor carries out entire compensation.This programme reduces the individual difference between different flow sensorIt is different so that flow sensor calibration uniformity is more preferable.
It should be noted that the step of being calibrated using calibration module flow sensor, can be in flow sensingDirectly progress calculates and obtains compensating factor when device dispatches from the factory, during the use of follow-up flow measuring unit, using compensating factor to flowSensor is calibrated；Can also be that during the use of flow sensor, real time calibration is carried out using calibration module.
Further, the flow sensor couples with PC calibration terminals, and the calibration method is further comprising the steps of：
S14, by PC calibration terminals by calibration factor and/or compensating factor value write diagnostics parameter, calibrated fluxes sensor justBeginning characterization data.
The PC calibration terminals of this programme be used for automate fitting flow sensor working curve and calculate obtain calibration factor and/Or the characterisitic parameter such as compensating factor value, and flow sensor is write, data correction is carried out using PC calibration terminals flow sensor,Simplify calibration steps so that calibration efficiency is higher.
Further, the PC calibration terminals couple with flow controller, and the flow controller flows through flow for controlThe fluid flow of sensor.
The foregoing is merely illustrative of the preferred embodiments of the present invention, is not intended to limit the invention, all essences in the present inventionAny modifications, equivalent substitutions and improvements made within refreshing and principle etc., should be included in the scope of the protection.