CN102997979A - Differential pressure flowmeter verification system - Google Patents
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Abstract
为克服现有技术差压流量计检定系统存在的检定误差较大和操作繁杂等问题，本发明提出一种差压流量计检定系统，包括工业计算机、差压检定模块、电磁流量计标准表和HART转换器；差压检定模块包括数据处理模块和控制模块且内置于工业计算机；HART转换器的一端连接待检定差压流量计变送器内置的HART接口，另一端通过计算机接口连接差压检定模块的数据处理模块；电磁流量计标准表通过自带的RS232数据接口与工业计算机连接。本发明差压流量计检定系统的有益技术效果是避免了检定表数据采集阶段的系统误差和一些误操作导致的错误，提高了检定结果的准确性，提高了工作效率。
In order to overcome the problems of relatively large verification errors and complicated operations in the prior art differential pressure flowmeter verification system, the present invention proposes a differential pressure flowmeter verification system, including an industrial computer, a differential pressure verification module, an electromagnetic flowmeter standard meter and a HART Converter; the differential pressure verification module includes a data processing module and a control module and is built into an industrial computer; one end of the HART converter is connected to the built-in HART interface of the differential pressure flowmeter transmitter to be verified, and the other end is connected to the differential pressure verification module through the computer interface The data processing module; the electromagnetic flowmeter standard meter is connected to the industrial computer through the built-in RS232 data interface. The beneficial technical effect of the differential pressure flowmeter verification system of the present invention is to avoid systematic errors in the data collection stage of the verification table and errors caused by some misoperations, improve the accuracy of verification results, and improve work efficiency.
Description
the
发明领域 field of invention
本发明涉及到差压流量计检定技术，特别涉及到一种差压流量计检定系统。 The invention relates to a differential pressure flowmeter verification technology, in particular to a differential pressure flowmeter verification system.
背景技术 Background technique
现有技术差压流量计检定系统是通过电压信号采集积算仪对待检定差压流量计（以下简称为检定表）变送器输出的4-20mA的电流输出信号进行采集和计算来获得检定表的差压值。其具体过程是电压信号采集积算仪通过一个电流电压转换电路将检定表变送器输出的电流信号转换为电压信号，然后，由电压信号采集积算仪内置的模数转换模块AD（以下简称为AD模块）将电压信号转换为数字信号，再通过算法处理，即可得到检定表的当前差压值。将检测到的检定表的差压值与标定系统中的标准差压流量计的瞬时流量值进行比较，通过多次相同的测试即可得到标定所需的线性度、重复性误差和流出系数等检定数据。由于检定表变送器在处理瞬时流量和输出电流值时存在计算误差，差压电流计输出的电流值与其瞬时流量并不完全成正比，由此可能引起检定误差。又由于将检定表变送器输出的电流信号转换为电压信号的电流电压转换电路存在的硬件误差，以及AD模块采样分辨率所引起的误差，进一步增加了检定误差。另外，检定过程中需要检定人员手动输入每个参数和数据到计算表格中，不仅操作繁杂，还容易出现操作失误，从而导致检定结果错误。显然，现有技术差压流量计检定系统存在着检定误差较大和操作繁杂等问题。 The prior art differential pressure flowmeter verification system obtains the verification table by collecting and calculating the 4-20mA current output signal output by the transmitter of the differential pressure flowmeter to be verified (hereinafter referred to as the verification table) by the voltage signal acquisition integrator. differential pressure value. The specific process is that the voltage signal acquisition integrator converts the current signal output by the calibration meter transmitter into a voltage signal through a current-voltage conversion circuit, and then, the analog-to-digital conversion module AD (hereinafter referred to as It is the AD module) to convert the voltage signal into a digital signal, and then through the algorithm processing, the current differential pressure value of the calibration table can be obtained. Compare the detected differential pressure value of the calibration meter with the instantaneous flow value of the standard differential pressure flowmeter in the calibration system, and obtain the linearity, repeatability error and outflow coefficient required for calibration through multiple identical tests test data. Because the calibration meter transmitter has calculation errors when dealing with instantaneous flow and output current values, the current value output by the differential pressure ammeter is not completely proportional to its instantaneous flow, which may cause verification errors. The verification error is further increased due to the hardware error of the current-voltage conversion circuit that converts the current signal output by the verification meter transmitter into a voltage signal, and the error caused by the sampling resolution of the AD module. In addition, during the verification process, the verification personnel need to manually input each parameter and data into the calculation form, which is not only complicated to operate, but also prone to operational errors, resulting in incorrect verification results. Apparently, the prior art differential pressure flowmeter verification system has problems such as large verification error and complicated operation.
发明内容 Contents of the invention
为克服现有技术差压流量计检定系统存在的检定误差较大和操作繁杂等问题，本发明提出一种差压流量计检定系统。本发明差压流量计检定系统包括工业计算机、差压检定模块、电磁流量计标准表和HART转换器；差压检定模块包括数据处理模块和控制模块且内置于工业计算机；HART转换器的一端连接待检定差压流量计变送器内置的HART接口，另一端通过计算机接口连接差压检定模块的数据处理模块；电磁流量计标准表通过自带的RS232数据接口与工业计算机连接。 In order to overcome the problems of large verification error and complicated operation in the prior art differential pressure flowmeter verification system, the present invention proposes a differential pressure flowmeter verification system. The differential pressure flowmeter verification system of the present invention includes an industrial computer, a differential pressure verification module, an electromagnetic flowmeter standard meter and a HART converter; the differential pressure verification module includes a data processing module and a control module and is built into the industrial computer; one end of the HART converter is connected The built-in HART interface of the differential pressure flowmeter transmitter to be verified is connected to the data processing module of the differential pressure verification module through the computer interface; the standard meter of the electromagnetic flowmeter is connected to the industrial computer through the built-in RS232 data interface.
进一步的，本发明差压流量计检定系统的HART转换器能够将待检定差压流量计使用的HART协议物理信号和工业计算机的RS-232串行信号进行相互转换。 Further, the HART converter of the differential pressure flowmeter verification system of the present invention can convert the HART protocol physical signal used by the differential pressure flowmeter to be verified and the RS-232 serial signal of the industrial computer to each other.
进一步的，本发明差压流量计检定系统的数据处理模块能够读取待检定差压流量计和电磁流量计标准表的数据并显示，其中，待检定差压流量计的基本信息包括制造商识别码、制造商设备类型码和设备标识号以及检定过程中的差压值、电流值和流量百分比；电磁流量计标准表的基本信息包括瞬时流量和累计流量。 Further, the data processing module of the differential pressure flowmeter verification system of the present invention can read and display the data of the differential pressure flowmeter to be verified and the standard table of the electromagnetic flowmeter, wherein the basic information of the differential pressure flowmeter to be verified includes the manufacturer identification Code, manufacturer's equipment type code and equipment identification number, as well as differential pressure value, current value and flow percentage during the verification process; the basic information of the electromagnetic flowmeter standard table includes instantaneous flow and cumulative flow.
进一步的，本发明差压流量计检定系统的数据处理模块根据设定的标定流量点和时间定时采集每个设定的标定流量点待检定差压流量计的差压值和电磁流量计标准表累计值，并对采集的数据进行误差计算和计算结果的处理。 Further, the data processing module of the differential pressure flowmeter verification system of the present invention regularly collects the differential pressure value of the differential pressure flowmeter to be verified at each set calibration flow point and the standard table of the electromagnetic flowmeter according to the set calibration flow point and time Accumulate the value, and perform error calculation and calculation result processing on the collected data. the
进一步的，本发明差压流量计检定系统的数据处理模块能够计算并显示检定中的过程参数以及检定结果数据并保存，其中，过程参数包括待检定差压流量计的差压值、电流值和流量百分比，以及电磁流量计标准表的瞬时流量和累计流量；检定结果数据包括流出系数、线性度、重复性、反映测量介质密度和差压值关系的系数K和不确定度。 Further, the data processing module of the differential pressure flowmeter verification system of the present invention can calculate and display the process parameters in the verification and the verification result data and save them, wherein the process parameters include the differential pressure value, current value and Flow percentage, as well as the instantaneous flow and cumulative flow of the electromagnetic flowmeter standard table; the verification result data includes discharge coefficient, linearity, repeatability, coefficient K and uncertainty reflecting the relationship between the density of the measured medium and the differential pressure value.
本发明差压流量计检定系统的有益技术效果是避免了检定表数据采集阶段的系统误差和一些误操作导致的错误，提高了检定结果的准确性，提高了工作效率。 The beneficial technical effect of the differential pressure flowmeter verification system of the present invention is to avoid systematic errors in the data collection stage of the verification table and errors caused by some misoperations, improve the accuracy of verification results, and improve work efficiency.
附图说明 Description of drawings
附图1是本发明差压流量计检定系统的结构示意图。 Accompanying drawing 1 is the structural diagram of the differential pressure flowmeter verification system of the present invention.
下面结合附图及具体实施例对本发明差压流量计检定系统作进一步的说明。 The differential pressure flowmeter verification system of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.
具体实施方式 Detailed ways
附图1是本发明差压流量计检定系统的结构示意图。由图可知，本发明差压流量计检定系统包括工业计算机、差压检定模块、电磁流量计标准表和HART转换器；差压检定模块包括数据处理模块和控制模块且内置于工业计算机；HART转换器的一端连接待检定差压流量计变送器内置的HART接口，另一端通过计算机接口连接差压检定模块的数据处理模块；电磁流量计标准表通过自带的RS232数据接口与工业计算机连接。 Accompanying drawing 1 is the structural diagram of the differential pressure flowmeter verification system of the present invention. As can be seen from the figure, the differential pressure flowmeter verification system of the present invention includes an industrial computer, a differential pressure verification module, an electromagnetic flowmeter standard gauge and a HART converter; the differential pressure verification module includes a data processing module and a control module and is built into the industrial computer; the HART conversion One end of the transmitter is connected to the built-in HART interface of the differential pressure flowmeter transmitter to be verified, and the other end is connected to the data processing module of the differential pressure verification module through the computer interface; the standard meter of the electromagnetic flowmeter is connected to the industrial computer through the built-in RS232 data interface.
本发明差压流量计检定系统的HART转换器能够将待检定差压流量计使用的HART协议物理信号和工业计算机的RS-232串行信号进行相互转换，其数据处理模块能够读取待检定差压流量计和电磁流量计标准表的数据并显示；其中，待检定差压流量计的基本信息包括制造商识别码、制造商设备类型码和设备标识号以及检定过程中的差压值、电流值和流量百分比；电磁流量计标准表的的基本信息包括瞬时流量和累计流量。 The HART converter of the differential pressure flowmeter verification system of the present invention can convert the HART protocol physical signal used by the differential pressure flowmeter to be verified and the RS-232 serial signal of the industrial computer to each other, and its data processing module can read the differential pressure flowmeter to be verified. The data of the pressure flowmeter and electromagnetic flowmeter standard table can be displayed; among them, the basic information of the differential pressure flowmeter to be verified includes the manufacturer identification code, the manufacturer's equipment type code and equipment identification number, as well as the differential pressure value and current during the verification process. value and flow percentage; the basic information of the electromagnetic flowmeter standard table includes instantaneous flow and cumulative flow.
另外，本发明差压流量计检定系统的数据处理模块根据设定的标定流量点和时间定时采集每个设定的标定流量点待检定差压流量计的差压值和电磁流量计标准表累计值，并对采集的数据进行误差计算和计算结果的处理；能够计算并显示检定中的过程参数以及检定结果数据并保存，其中，过程参数包括待检定差压流量计的差压值、电流值和流量百分比，以及电磁流量计标准表的瞬时流量和累计流量；检定结果数据包括流出系数、线性度、重复性、反映测量介质密度和差压值关系的系数K和不确定度。 In addition, the data processing module of the differential pressure flowmeter verification system of the present invention regularly collects the differential pressure value of the differential pressure flowmeter to be verified at each set calibration flow point and the accumulated value of the standard table of the electromagnetic flowmeter according to the set calibration flow point and time. value, and process the error calculation and calculation results of the collected data; it can calculate and display the process parameters in the verification and the verification result data and save them, among which, the process parameters include the differential pressure value and current value of the differential pressure flowmeter to be verified and flow percentage, as well as the instantaneous flow and cumulative flow of the electromagnetic flowmeter standard table; the verification result data includes discharge coefficient, linearity, repeatability, coefficient K and uncertainty reflecting the relationship between the density of the measured medium and the differential pressure value.
具体检定时，将工业计算机通过HART转换器分别连接到待检定差压流量计，并将电磁流量计标准表通过其自带的RS232数据接口连接到工业计算机。开启工业计算机并读取待检定差压流量计的基本信息，包括制造商识别码、制造商设备类型码和设备标识号。向工业计算机输入待检定差压流量计的计算书提供的参数并设定标定流量点和时间，所述计算书为根据差压流量计的设计参数所编制的检定指导性文件。在调节好管道流量值后，本发明差压流量计检定系统将对每个设定的标定流量点待检定差压流量计的差压值和电磁流量计标准表累计值进行采集并进行误差计算，待所有流量点标定完成后本发明差压流量计检定系统会计算并保存检定结果数据，包括流出系数、线性度、重复性、反映测量介质密度和差压值关系的系数K和不确定度等。本发明差压流量计检定系统没有从待检定差压流量计采集电流信号进行检测，而是从待检定差压流量计变送器的HART接口直接读取差压值（因为差压流量计变送器可以直接从内置的HART接口输出各项参数或实时数据，所以通过一个HART转换器将差压流量计的变送器直接与计算机相连，然后在计算机即可直接得到与差压流量计当前显示一致的差压值），这样就完全避免了现有技术差压流量计检定系统信号采集过程中所产生的一系列误差。另外，本发明差压流量计检定系统能够实时显示检定过程中的过程参数以及检定结果数据并保存，其中，过程参数包括待检定差压流量计的差压值、电流值和流量百分比，以及电磁流量计标准表的瞬时流量和累计流量；检定结果数据包括流出系数、线性度、重复性、反映测量介质密度和差压值关系的系数K和不确定度。再有，采用本发明差压流量计检定系统，减少了操作人员的人为操作，系统自动完成所有的数据采集操作，避免了人为因素的影响，减少了人为误差。 During the specific verification, the industrial computer is connected to the differential pressure flowmeter to be verified through the HART converter, and the standard meter of the electromagnetic flowmeter is connected to the industrial computer through its own RS232 data interface. Turn on the industrial computer and read the basic information of the differential pressure flowmeter to be verified, including the manufacturer's identification code, manufacturer's equipment type code and equipment identification number. Input the parameters provided by the calculation book of the differential pressure flowmeter to be verified into the industrial computer and set the calibration flow point and time. The calculation book is a verification guidance document compiled according to the design parameters of the differential pressure flowmeter. After the pipeline flow value is adjusted, the differential pressure flowmeter verification system of the present invention will collect the differential pressure value of the differential pressure flowmeter to be verified at each set calibration flow point and the cumulative value of the standard meter of the electromagnetic flowmeter and perform error calculation , after the calibration of all flow points is completed, the differential pressure flowmeter verification system of the present invention will calculate and save the verification result data, including the outflow coefficient, linearity, repeatability, coefficient K and uncertainty reflecting the relationship between the density of the measurement medium and the differential pressure value wait. The differential pressure flowmeter verification system of the present invention does not collect current signals from the differential pressure flowmeter to be verified for detection, but directly reads the differential pressure value from the HART interface of the differential pressure flowmeter transmitter to be verified (because the differential pressure flowmeter changes The transmitter can directly output various parameters or real-time data from the built-in HART interface, so the transmitter of the differential pressure flowmeter is directly connected to the computer through a HART converter, and then the computer can directly get the current status of the differential pressure flowmeter. In this way, a series of errors generated in the signal acquisition process of the differential pressure flowmeter verification system in the prior art are completely avoided. In addition, the differential pressure flowmeter verification system of the present invention can display and save the process parameters and verification result data in the verification process in real time, wherein the process parameters include the differential pressure value, current value and flow rate of the differential pressure flowmeter to be verified, and the electromagnetic The instantaneous flow rate and cumulative flow rate of the flowmeter standard meter; the verification result data includes discharge coefficient, linearity, repeatability, coefficient K and uncertainty reflecting the relationship between the density of the measured medium and the differential pressure value. Furthermore, the use of the differential pressure flowmeter verification system of the present invention reduces the manual operations of operators, and the system automatically completes all data collection operations, avoiding the influence of human factors and reducing human errors.
显然，本发明差压流量计检定系统的有益技术效果是避免了检定表数据采集阶段的系统误差和一些误操作导致的错误，提高了检定结果的准确性，提高了工作效率。 Obviously, the beneficial technical effect of the differential pressure flowmeter verification system of the present invention is to avoid systematic errors in the data collection stage of the verification table and errors caused by some misoperations, improve the accuracy of verification results, and improve work efficiency.
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104266731A (en) * | 2014-10-21 | 2015-01-07 | 中山欧麦克仪器设备有限公司 | System for Validating Magnetic Flow Meters |
| CN105136251A (en) * | 2014-06-09 | 2015-12-09 | 浙江海洋学院 | Method for detecting air mass flowmeter |
| CN106679770A (en) * | 2016-11-22 | 2017-05-17 | 重庆川仪自动化股份有限公司 | Mass calibration system and method for mass flow meter |
| CN107764360A (en) * | 2016-08-23 | 2018-03-06 | 国家电投集团科学技术研究院有限公司 | Control method, control device and the digital instrument of digital instrument |
| CN108318110A (en) * | 2017-12-25 | 2018-07-24 | 中核北方核燃料元件有限公司 | A kind of minute gas meter proof calibrating installation |
| CN109506745A (en) * | 2018-12-17 | 2019-03-22 | 杭州晶锐仪器仪表有限公司 | A kind of calibration method of Ultrasonic Wave Flowmeter analog output module |
| CN110462346A (en) * | 2017-03-23 | 2019-11-15 | 霍尼韦尔国际公司 | The device and method for generating inferential process flow measurements for using flow restrictor and upstream pressure measurement and downstream pressure measurement |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012037457A (en) * | 2010-08-10 | 2012-02-23 | Ace:Kk | Flow rate standard and flow rate calibration method using the same |
| KR20120067438A (en) * | 2010-12-16 | 2012-06-26 | 한국수자원공사 | Flow meter calibration device |
| CN202350878U (en) * | 2011-11-08 | 2012-07-25 | 合肥科迈捷智能传感技术有限公司 | Automatic checking device for flow meter |
| CN202575957U (en) * | 2012-03-14 | 2012-12-05 | 修武县电业公司 | Flammable and explosive liquid material loading system |
-
2012
- 2012-12-27 CN CN201210577953.5A patent/CN102997979B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012037457A (en) * | 2010-08-10 | 2012-02-23 | Ace:Kk | Flow rate standard and flow rate calibration method using the same |
| KR20120067438A (en) * | 2010-12-16 | 2012-06-26 | 한국수자원공사 | Flow meter calibration device |
| CN202350878U (en) * | 2011-11-08 | 2012-07-25 | 合肥科迈捷智能传感技术有限公司 | Automatic checking device for flow meter |
| CN202575957U (en) * | 2012-03-14 | 2012-12-05 | 修武县电业公司 | Flammable and explosive liquid material loading system |
Non-Patent Citations (3)
| Title |
|---|
| 国家技术监督局: "《JJG640-1994 差压式流量计检定规程》", 1 December 1994, article "JJG640-1994 差压式流量计检定规程" * |
| 国家技术监督局: "《JJG882-1994 压力变送器检定规程》", 1 February 1995, article "JJG882-1994 压力变送器检定规程" * |
| 国家质量监督检验检疫总局: "《JJG875-2005 数字压力计》", 20 December 2005, article "JJG875-2005 数字压力计" * |
Cited By (8)
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