CN103185614A - Differential pressure flow transmitter with multiple ranges and automatic range switching function - Google Patents
Differential pressure flow transmitter with multiple ranges and automatic range switching function Download PDFInfo
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- CN103185614A CN103185614A CN2013100504333A CN201310050433A CN103185614A CN 103185614 A CN103185614 A CN 103185614A CN 2013100504333 A CN2013100504333 A CN 2013100504333A CN 201310050433 A CN201310050433 A CN 201310050433A CN 103185614 A CN103185614 A CN 103185614A
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Abstract
The invention provides a differential pressure flow transmitter with multiple ranges and an automatic range switching function. The differential pressure flow transmitter is characterized in that an input differential pressure signal is converted into an electric signal through a sensing element and modulated into a digital signal through amplification and analog-digital conversion to be sent to a singlechip microprocessor; the signal is subjected to linearization, compensation, calculation, self-diagnosis and communication control under the coordination control of a control procedure; automatic range switching is performed through setting of the multiple ranges as well as comparison judgment of a measuring value and an adjacent range characteristic value; and a direct current signal or a digital signal is output by an analog-digital conversion unit and a digital output unit for displaying, and transmitted to a secondary instrument. By means of switching of the ranges at the right moment, the measuring value is enabled to work nearby an upper limit value of a corresponding range of the transmitter all the time, so that the relative error of the measurement is reduced, the measuring accuracy is improved, and the quality of the transmitter is improved.
Description
Technical field
The present invention relates to instrument field, is a kind of differential flow converter with multirange and automatic range handoff functionality.
Background technology
The function of differential flow converter (hereinafter to be referred as transmitter) mainly converts electric signal in order to the state-variables such as flow with liquid, gas and carries out the process variable demonstration, and be transferred to measurement or the control that realizes the fluid technological parameter on demonstration, recorder or the computing machine, have widespread use in commercial measurement and energy field.
Two the key technical indexes of transmitter are to measure range and accuracy of measurement, and range is one section surveying work zone in the specified input signal measurement range of transmitter, and associated is range ratio.It refers to the ratio of the interior maximum range of measurement range and minimum range, and general performance intelligent transmitter range ratio preferably can reach 100:1 or higher.Measurement range such as transmitter is 0-1-100 kPa, and its maximum range is that 0-100 kPa minimum range is 0-1kPa, and range ratio is 100:1, and range ratio is more big to show that the available scope of transmitter range is more big.Though transmitter has very big range ratio at present, can only select and fix one of them range to be used as the work range in measurement range.
The accuracy of transmitter defines with fiducial error, fiducial error=
And by the relative error formula: relative error=
As can be known, the measurement relative error of each point is different in the transmitter range, have only the measurement relative error of range upper change point identical with fiducial error, can reach accuracy rating, and the relative error of other point is greater than accuracy rating in range, and it is more big that measurement point departs from range upper limit measurement relative error.Be that 0-100kPa, 0.075% grade transmitter are example with the range, the permission absolute error in its gamut is 0.075kPa, and the relative error at maximum range 100 kPa places also is 0.075%; And at 3.75% also i.e. 3.75 kPa places of range, the measurement relative error of differential pressure transmitter is 0.075/0.375=2%.And for the flow transmitter of 0.075 grade of accuracy with extracting operation function, when flow reduce to full scale 19.36% the time measure relative error and be increased to 1% by 0.075%.If turn the range of transmitter in this case down, whether can improve accuracy, be all example, if this moment, the range of differential pressure transmitter was adjusted into 1/10th original (being that range becomes 0-10kPa), then the permission absolute error in the gamut also is reduced to originally 1/10th, is 0.0075kPa; Measure relative error during for 3.75kPa when tested force value and be reduced to 0.0075/3.75=0.2%, obviously bring up to 0.2% by 2% with respect to original wide range situation accuracy of measurement, promoted 10 times, the situation of flow transmitter is herewith similar.
Hence one can see that, when selecting suitable range and measured value being worked near near the range upper limit, can obtain higher accuracy of measurement.But transmitter has only a fixedly range at present, when the measured flux fluctuation range is measured low discharge than big or use wide range transmitter, a range can't resolve large-scale accuracy of measurement problem, the industrial way that adopts a measured parameter that two cover flowmeters are installed sometimes, cause investment to increase, nonetheless its range overlay area be still limited, the accuracy that influence is measured.The present invention is directed to the deficiency on the present transmitter performance, design the differential flow converter with multirange and automatic range handoff functionality.
Conventional at present transmitter has higher accuracy class and very big range ratio, but has only one to use range.Because the characteristic of transmitter causes the measurement relative error of its each working point in range greater than accuracy rating, the range upper change point is measured relative error and is equaled accuracy rating, measured value departs from the range upper limit, and then measuring error is more big, often exceeds the accuracy requirement of measuring process.
Summary of the invention
The objective of the invention is, above-mentioned drawback at present conventional transmitter, design a kind of differential flow converter that in whole measurement range, has a plurality of ranges and automatic range handoff functionality, measured value is operated near the higher limit of corresponding range always, reduce the relative error of measuring, improve accuracy of measurement.
Realize that the technical scheme that the object of the invention is taked is: a kind of differential flow converter with a plurality of ranges and automatic range handoff functionality, it is characterized in that: will import differential pressure signal and convert electric signal to by sensing element, through amplifying and analog to digital conversion, be modulated into digital signal and deliver to singlechip microprocessor, coordination control by control program is carried out linearization to signal, compensation, calculate, self diagnosis, Control on Communication, set by multirange, the relatively judgement of measured value and adjacent range eigenwert, the implementation automatic range switches, process D/A conversion unit and digital output unit output DC stream signal or digital signal show again, and are transferred to secondary instrument.
Described multirange is whole or the part measurement range is interior is divided into several different use ranges according to flow value or force value, and each range code and coefficient of ranger are set.
The eigenwert of described measured value and place range and the eigenwert of other range are compared judgement, satisfy more than or equal to, perhaps smaller or equal to the switching of carrying out automatically after the condition between corresponding range, eigenwert is any value in the specified measurement scope.
The relatively judgement relation of described measured value and adjacent range eigenwert, mathematical relation and control program that automatic range switches, mathematical relation comprises: to be limited to starting point under the same range or to be limited to the multirange partition mode of starting point under the different ranges, the coefficient of ranger pattern, subsidiary condition pattern when range switches.
Differential flow converter with a plurality of ranges and automatic range handoff functionality of the present invention can be according to measuring and control parameter and changeover program, and microprocessor calls and carries out, thereby finishes the automatic switchover of range.Its function embodiment that possesses exists:
1. accept setting and code identification and the storage to each range in the measurement range from the operator by interface, and energising acquiescence range is set.For example: measurement range is the transmitter of 0-1-100kPa, and to being divided into 10 range sections between its 0-1kPa to 0-100kPa, 01 represents 0-100kPa, 02 represents 0-50kPa...10 and represent 0-1kPa etc., and energising back acquiescence range is 01;
2. arranging of each range need be carried out synchronously at the timing signal to each range, and transmitter is applied standard differential pressure value with each range, corresponding range confirmed, and calculated the generation coefficient of ranger automatically by the transmitter internal processes, determines input/output relation;
3. accept and storage range changeover program and other measurement and control parameter, switch preceding continual and steady time of measured value, amplitude and the rate of change of variation as range, these parameters are referred to as the subsidiary condition that range switches, and all above parameters are stored in to avoid in the eeprom memory having a power failure loses;
4. control program regularly scanned contents of program according to the time cycle of operation, and the measured value that collects is compared judgement in adjacent range eigenwert, to determine whether that need carry out range switches;
5. transmitter calculates the measured value in range switching front and back and the handoff procedure and shows, and transmit, displayed value can be differential pressure, pressure or flow etc., also can be DC current or voltage signal, signal transmission form can be that digital communication mode or DC simulation output load digital signaling, and the transmission content is measurement data and the range handover information after automatic range switches;
6. can make transmitter in whole measurement range, obtain high accuracy by the automatic switchover of multirange and range is set, it is different with the performance compensation to a certain element of transmitter with revising, be under the constant prerequisite of transmitter original physical performance, reduce measuring error by dwindling range.
Description of drawings
Fig. 1 is the block diagram with differential flow converter of a plurality of ranges and automatic range handoff functionality;
Fig. 2 is that the whole or part measurement range with differential flow converter of a plurality of ranges and automatic range handoff functionality is divided into several range synoptic diagram;
Fig. 3 is the slope synoptic diagram of input-output characteristic curve of each range with differential flow converter of a plurality of ranges and automatic range handoff functionality;
Fig. 4 is the range switching controls schematic flow sheet with differential flow converter of a plurality of ranges and automatic range handoff functionality.
Embodiment
With reference to Fig. 1, input differential pressure signal process sensing element 1 with differential flow converter of a plurality of ranges and automatic range handoff functionality of the present invention, be converted into electric signal and give amplification and A/D AD conversion unit 2, signal after the modulation is delivered to singlechip microprocessor 3, control parameter and control program are stored in the eeprom memory 4, by realize the linearization of signal with the exchanges data of microprocessor 3, compensation, range is judged switching, self diagnosis, procedure stores control etc. are given secondary instrument 6 through D/A D/A conversion unit 5 output DCs stream signal or digital signal then.Concrete principle of work is, to import differential pressure signal and convert electric signal to by sensing element 1, amplification and analog to digital conversion through amplification and A/D AD conversion unit 2, be modulated into digital signal and deliver to singlechip microprocessor 3, control parameter and control program are stored in the eeprom memory 4, coordination control by control program is carried out linearization to signal, compensation, calculate, self diagnosis, Control on Communication, set by multirange, the relatively judgement of measured value and adjacent range eigenwert, the implementation automatic range switches, and demonstration and the digital communication function of range switching back measured value, carry out digital-to-analog conversion and digital output DC stream signal or digital signal through D/A D/A conversion unit 5 again and give secondary instrument 6.Described multirange is whole or the part measurement range is interior is divided into several different use ranges according to flow value or force value, and each range code and coefficient of ranger are set.The eigenwert of described measured value and place range and the eigenwert of other range are compared judgement, satisfy more than or equal to, perhaps smaller or equal to the switching of carrying out automatically after the condition between corresponding range, eigenwert is any value in the specified measurement scope.The relatively judgement relation of described measured value and adjacent range eigenwert, mathematical relation and control program that automatic range switches, mathematical relation comprises: to be limited to starting point under the same range or to be limited to the multirange partition mode of starting point under the different ranges, the coefficient of ranger pattern, subsidiary condition pattern when range switches.
Typical case's typical circuit formation is exemplified as: differential pressure sensing element 1 is capacitance type sensor; The A/D module of amplification and A/D AD conversion unit 2 is the MAX1400 chip; Microprocessor 3 is the PIC16C73 single-chip microcomputer; The D/A module of D/A D/A conversion unit 5 is the AD421 chip.
With reference to Fig. 2, multirange setting and automatic range handoff functionality are between measurement range lower limit and the upper limit, the whole of transmitter or part measurement range are divided into several ranges, and it can be being limited to the range starting point under the same range that this range is divided, and wide range is contained little range.
With reference to Fig. 3, determine the coefficient of ranger of each range, coefficient of ranger is the slope of the input-output characteristic curve of each range, k=tan α=(maximum output-minimum output)/(the range upper limit-range lower limit).The coefficient of ranger of range 1-n is respectively K1, K2, K3 ... Kn.
With reference to Fig. 4, when transmitter is worked, determine the relation of input and output with this coefficient of ranger under current range.And compare successively to the eigenwert (being generally the range higher limit) of current measured value and place range and with eigenwert less than the adjacent range of place range and judge by programmed control, whether overflow place range higher limit, perhaps whether less than the higher limit of adjacent range.If then satisfy the most important condition that range switches, again range being switched required subsidiary condition such as stabilization time, amplitude of variation and rate of change judges, the back program that satisfies condition switches to transmitter under this range automatically works, and carries out signal output with the coefficient of ranger under this range.Under new work range, proceed relatively to judge and switch afterwards, by that analogy, make transmitter carry out range automatically along with the measured value change and switch.In good time switching by range is operated near the higher limit of corresponding range of transmitter measured value always.
The specific embodiment of the present invention only is an instantiation, but also non exhaustive, and those skilled in the art all belong to the scope that claim of the present invention is protected without simple copy and the improvement of creative work.
Claims (5)
1. differential flow converter with a plurality of ranges and automatic range handoff functionality, it is characterized in that: will import differential pressure signal and convert electric signal to by sensing element, through amplifying and analog to digital conversion, be modulated into digital signal and deliver to singlechip microprocessor, coordination control by control program is carried out linearization to signal, compensation, calculate, self diagnosis, Control on Communication, set by multirange, the relatively judgement of measured value and adjacent range eigenwert, the implementation automatic range switches, process D/A conversion unit and digital output unit output DC stream signal or digital signal show again, and are transferred to secondary instrument.
2. according to right 1 described differential flow converter with a plurality of ranges and automatic range handoff functionality, it is characterized in that: described multirange is whole or the part measurement range is interior is divided into several different use ranges according to flow value or force value, and each range code and coefficient of ranger are set.
3. according to right 1 described differential flow converter with a plurality of ranges and automatic range handoff functionality, it is characterized in that: the eigenwert of described measured value and place range and the eigenwert of other range are compared judgement, satisfy more than or equal to, perhaps smaller or equal to the switching of carrying out automatically after the condition between corresponding range, eigenwert is any value in the specified measurement scope.
4. according to right 1 described differential flow converter with a plurality of ranges and automatic range handoff functionality, it is characterized in that: the relatively judgement relation of described measured value and adjacent range eigenwert, mathematical relation and control program that automatic range switches, mathematical relation comprises: to be limited to starting point under the same range or to be limited to the multirange partition mode of starting point under the different ranges, the coefficient of ranger pattern, subsidiary condition pattern when range switches.
5. according to right 4 described differential flow converters with a plurality of ranges and automatic range handoff functionality, it is characterized in that: the subsidiary condition pattern was when described range switched: continual and steady time of measured value, amplitude of variation and rate of change.
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Cited By (20)
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| CN103335678A (en) * | 2013-07-24 | 2013-10-02 | 中环天仪股份有限公司 | Control method for automatically switching measuring ranges of electromagnetic flowmeter |
| CN104090068A (en) * | 2014-01-03 | 2014-10-08 | 力合科技（湖南）股份有限公司 | Self-adaption method for measuring range of detection instrument |
| CN104748831A (en) * | 2015-03-23 | 2015-07-01 | 沈阳新一代信息技术有限公司 | Device and method for converting multi-range millivolt signal of weighing sensor |
| CN105784018A (en) * | 2016-04-19 | 2016-07-20 | 毕托巴（上海）科技有限公司 | Differential pressure transmitter |
| CN107167190A (en) * | 2017-06-29 | 2017-09-15 | 神雾环保技术股份有限公司 | The wide-range differential pressure flow detection means and method of two-flow scope |
| CN107247427A (en) * | 2017-07-18 | 2017-10-13 | 霍丁格包尔文(苏州)电子测量技术有限公司 | A kind of high-precision sensor signal transmitting device |
| CN107305176A (en) * | 2016-04-20 | 2017-10-31 | 毕托巴（上海）科技有限公司 | The measurement apparatus of oil plant averag density in a kind of oil tank |
| CN110286257A (en) * | 2019-06-20 | 2019-09-27 | 西安易朴通讯技术有限公司 | Electric current detecting method and device, electronic equipment and computer readable storage medium |
| CN110673077A (en) * | 2019-09-30 | 2020-01-10 | 上海商汤智能科技有限公司 | Data processing method and device, measuring instrument, measuring platform and storage medium |
| CN110941205A (en) * | 2018-09-21 | 2020-03-31 | 欧姆龙(上海)有限公司 | Sampling control device, sampling control method and electronic equipment |
| CN110989463A (en) * | 2019-12-24 | 2020-04-10 | 北京金迈捷科技有限公司 | Online measurement range switching system and method |
| CN111679105A (en) * | 2020-04-29 | 2020-09-18 | 深圳市科陆精密仪器有限公司 | Range switching method for electric meter, electric meter and storage medium |
| CN111896770A (en) * | 2020-07-16 | 2020-11-06 | 中国船舶重工集团公司第七0七研究所九江分部 | Processing circuit suitable for measuring flow velocity based on differential pressure principle |
| CN112104364A (en) * | 2020-09-02 | 2020-12-18 | 霍丁格必凯(苏州)电子测量技术有限公司 | Analog signal transmitter and frequency signal calibration method thereof |
| CN112378464A (en) * | 2020-09-28 | 2021-02-19 | 甘肃酒钢集团宏兴钢铁股份有限公司 | Small flow meter measuring device combined with uniform-velocity tube flow meter and method thereof |
| CN112903000A (en) * | 2021-03-26 | 2021-06-04 | 歌尔光学科技有限公司 | Sensor control method, sensor control device and storage medium |
| CN113432680A (en) * | 2021-06-08 | 2021-09-24 | 中广核工程有限公司 | Nuclear power plant reactor coolant system flow calibration method |
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| CN115078798A (en) * | 2022-07-26 | 2022-09-20 | 武汉格蓝若智能技术有限公司 | Current range switching method and current collecting device |
| CN112378464B (en) * | 2020-09-28 | 2024-07-02 | 甘肃酒钢集团宏兴钢铁股份有限公司 | Small flow metering device combined with uniform speed pipe flowmeter and method thereof |
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Cited By (23)
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| CN103335678A (en) * | 2013-07-24 | 2013-10-02 | 中环天仪股份有限公司 | Control method for automatically switching measuring ranges of electromagnetic flowmeter |
| CN104090068A (en) * | 2014-01-03 | 2014-10-08 | 力合科技（湖南）股份有限公司 | Self-adaption method for measuring range of detection instrument |
| CN104748831A (en) * | 2015-03-23 | 2015-07-01 | 沈阳新一代信息技术有限公司 | Device and method for converting multi-range millivolt signal of weighing sensor |
| CN105784018A (en) * | 2016-04-19 | 2016-07-20 | 毕托巴（上海）科技有限公司 | Differential pressure transmitter |
| CN107305176A (en) * | 2016-04-20 | 2017-10-31 | 毕托巴（上海）科技有限公司 | The measurement apparatus of oil plant averag density in a kind of oil tank |
| CN107167190A (en) * | 2017-06-29 | 2017-09-15 | 神雾环保技术股份有限公司 | The wide-range differential pressure flow detection means and method of two-flow scope |
| CN107247427A (en) * | 2017-07-18 | 2017-10-13 | 霍丁格包尔文(苏州)电子测量技术有限公司 | A kind of high-precision sensor signal transmitting device |
| CN110941205A (en) * | 2018-09-21 | 2020-03-31 | 欧姆龙(上海)有限公司 | Sampling control device, sampling control method and electronic equipment |
| CN110286257A (en) * | 2019-06-20 | 2019-09-27 | 西安易朴通讯技术有限公司 | Electric current detecting method and device, electronic equipment and computer readable storage medium |
| CN110673077B (en) * | 2019-09-30 | 2022-02-22 | 上海商汤智能科技有限公司 | Data processing method and device, measuring instrument, measuring platform and storage medium |
| CN110673077A (en) * | 2019-09-30 | 2020-01-10 | 上海商汤智能科技有限公司 | Data processing method and device, measuring instrument, measuring platform and storage medium |
| CN110989463A (en) * | 2019-12-24 | 2020-04-10 | 北京金迈捷科技有限公司 | Online measurement range switching system and method |
| CN111679105A (en) * | 2020-04-29 | 2020-09-18 | 深圳市科陆精密仪器有限公司 | Range switching method for electric meter, electric meter and storage medium |
| CN111896770A (en) * | 2020-07-16 | 2020-11-06 | 中国船舶重工集团公司第七0七研究所九江分部 | Processing circuit suitable for measuring flow velocity based on differential pressure principle |
| CN112104364A (en) * | 2020-09-02 | 2020-12-18 | 霍丁格必凯(苏州)电子测量技术有限公司 | Analog signal transmitter and frequency signal calibration method thereof |
| CN112378464A (en) * | 2020-09-28 | 2021-02-19 | 甘肃酒钢集团宏兴钢铁股份有限公司 | Small flow meter measuring device combined with uniform-velocity tube flow meter and method thereof |
| CN112378464B (en) * | 2020-09-28 | 2024-07-02 | 甘肃酒钢集团宏兴钢铁股份有限公司 | Small flow metering device combined with uniform speed pipe flowmeter and method thereof |
| CN112903000A (en) * | 2021-03-26 | 2021-06-04 | 歌尔光学科技有限公司 | Sensor control method, sensor control device and storage medium |
| CN113432680A (en) * | 2021-06-08 | 2021-09-24 | 中广核工程有限公司 | Nuclear power plant reactor coolant system flow calibration method |
| CN113432680B (en) * | 2021-06-08 | 2023-09-01 | 中广核工程有限公司 | Nuclear power plant reactor coolant system flow calibration method |
| CN113484655A (en) * | 2021-09-07 | 2021-10-08 | 西安热工研究院有限公司 | Redundant measurement line-crossing detection method, system and storage medium |
| CN113484655B (en) * | 2021-09-07 | 2022-01-25 | 西安热工研究院有限公司 | Redundant measurement line-crossing detection method, system and storage medium |
| CN115078798A (en) * | 2022-07-26 | 2022-09-20 | 武汉格蓝若智能技术有限公司 | Current range switching method and current collecting device |
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