CN101131419B - Frequency span calibration and detection method for digital oscilloscope - Google Patents
Frequency span calibration and detection method for digital oscilloscope Download PDFInfo
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- CN101131419B CN101131419B CN 200710094127 CN200710094127A CN101131419B CN 101131419 B CN101131419 B CN 101131419B CN 200710094127 CN200710094127 CN 200710094127 CN 200710094127 A CN200710094127 A CN 200710094127A CN 101131419 B CN101131419 B CN 101131419B
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Abstract
The present invention relates to a calibration method for frequency bandwidth of digital oscillograph for using the oscillograph prover controlled by computer to set and calibrate the digital oscillograph. The two parameters of oscillograph prover signal: f and Uf are input into the input ends of every channel in calibrated digital oscillograph. When the f is 50kHz, the frequency is keep out and Uf is adjusted finely to make the digital oscillograph display 6 grids of waveform and corresponding to the Uf0 -3dB; the frequency is near the modeling frequency bandwidth field and keep the amplitude to adjust the frequency value, while every changing the frequency value, the oscillograph will detect the present amplitude. After many comparing, the amplitude of digital oscillograph is Uf0.
Description
Technical field:
The present invention relates to relevant full-automatic assay calibration digital oscilloscope frequency span method.
Background technology:
For convenience fast to TDS3000﹠amp; The various digital oscilloscopes of TDS3000B series are not calibrated by the restriction in time and place, and realize full-automatic calibration.The major technique file of at present domestic and international calibrating and measuring digital oscilloscope: (1) IEC Standard, Publication 351-1, Expression of the properties of cathode-ray oscilloscopes (part 1:General), International Electrical Commission, 1976 (IEC standard 351-1, the cathode ray oscilloscope (CRO) definition (first: common segment), International Electrotechnical Commission, 1976); The international standard of general cathode ray oscilloscope (CRO) has been stipulated the index definition and the method for testing of analog oscilloscope; (2) IEEE Std 1057-1994, IEEE Standard for Digitizing WaveformRecorders (ieee standard, 1057-1994, digital waveform registering instrument ieee standard); U.S.'s industry standard that U.S. electric and Electronic Engineering Association work out is made regulation to the index and the method for testing of digital waveform stored record instrument; (3) GB/T 15289-1994, digital storage oscilloscope general technical specifications and method of testing.The special national standard of writing at digital storage oscilloscope; (4) JJF 1057-1998 digital oscilloscope calibrating standard proposes the relevant index of digitalized signature, and provides the measuring method of some parameters.
In sum, the present domestic vertification regulation of also not putting into effect at digital oscilloscope.Most measurement and calibration mechanism still still continues to use the analog oscilloscope vertification regulation digital oscilloscope is calibrated, and with the benefit of this method be: calibration item is fixed, and technology maturation, Error Calculation are accurately and reliably; Enforceability is strong, can reflect the performance index of digital oscilloscope to a certain extent; But also exist not enough, because different on digital oscilloscope and analog oscilloscope principle of work and the display mode, both have diverse amplitude and time measurement system, digital oscilloscope has multiple analysis, processing and triggering function concurrently simultaneously, if simply indiscriminately imitate the analog oscilloscope vertification regulation, can't embody the digitized feature of digital oscilloscope, be unfavorable for the development of digital oscilloscope measurement and calibration technology.
Oscillograph is patterned instrument, the instrument that digitizings such as it and numerical table show is different, when same signal is tested, be not as numerical table, the a certain parameter of signal is represented with the form of numeral, but its form with waveform is presented on the screen, so very directly perceived, but brought inconvenience also for our calibrated oscilloscope, because we can't analyzing the shown waveform direct quantitative of oscillograph, can only rely on the scale on the screen, the display error that the contrast scale comes observation oscilloscope.Therefore, be to rely on human eye that the waveform that is presented on the screen is observed to the classic method of Oscilloscope Calibration always, judge the error of waveform according to the scale of screen, and then judge the quality of oscillograph displayed image.This process more complicated, operation steps to oscillograph and prover is very loaded down with trivial details, the beginner is difficult to remember the step of Chu's operation and setting, simultaneously, workload is also bigger, in case carry out extensive calibration, be easy to generate visual fatigue, and the personal error amount of influence is bigger, and different testing staff calibrate same digital oscilloscope, might influence calibration result because its cognition or naked eyes ability to see things in their true light are different.
Digital oscilloscope then has very big development.With respect to traditional analog oscilloscope, because digital oscilloscope itself carries automatic measurement function, not only can display waveform, can also provide measurement data to a lot of parameters of waveform, just as " numerical table " that can display waveform, thereby it can carry out quantitatively display waveform.Therefore also need brand-new calibrating mode, if can come the analytic signal waveform with automatic measurement function with the parameter of the quantitative analytic signal waveform of digital oscilloscope, so, just can be with digital oscilloscope and computer, prover couples together, and provides possibility for realizing full-automatic calibration.
Concerning digital oscilloscope, be 100MHz or 300MHz or 500MHz though on instrument panel, indicate analog bandwidth, actual real analog bandwidth has nothing in common with each other, and bandwidth can be different because of " machine ".The digital oscilloscope bandwidth that model is identical is marked as 500MHz equally, but may can reach 600～700MHz by certain oscillograph bandwidth measured value, and another then has only about the 520MHz.The automatic calibration software of lot of domestic and international digital oscilloscope is when calibration digital oscilloscope frequency span, and its method principle is relatively simple, and it is digital oscilloscope bandwidth f that oscilloscope calibrator sends frequency
0Sine wave signal, be marked as 500MHz as the oscillograph bandwidth, be that the sine wave signal of 500MHz is given digital oscilloscope just oscilloscope calibrator sends frequency, as long as the digital oscilloscope range value is greater than U
F0, promptly provide the conclusion of " Pass ".
Summary of the invention:
The present invention seeks to: the method that a kind of automatic calibration digital oscilloscope frequency span is provided, mainly solve existing digital oscilloscope calibrating standard and realize the big technical matters of difficulty, by this method of the present invention, can be fully according to " JJG262-1996, the analog oscilloscope vertification regulation ", the requirement of " JJF1057-1998 digital oscilloscope calibrating standard " etc., the digital oscilloscope frequency span is automatically calibrated.In the full-automatic calibration system of digital oscilloscope, can carry out selftest (Self Test) to digital oscilloscope; Trigger sensitivity (comprising internal trigger and external trigger); The DC current gain accuracy of measurement; The square wave accuracy of measurement; Frequency span; Bandwidth constraints; Transient response; The calibration operation of a plurality of projects such as long period and delay time measurement accuracy, calibration is according to meeting " JJG262-1996, analog oscilloscope vertification regulation ", " JJF1057-1998 digital oscilloscope calibrating standard " and " TDS3000B series digit oscillograph technical specification " fully.In conjunction with the calibrating of trigger sensitivity, utilize the automatic measurement function of digital oscilloscope simultaneously, can efficiently finish the calibrating and measuring of the leading indicator of digital oscilloscope.
The method of full-automatic calibration digital oscilloscope frequency span, its ultimate principle is consistent with manual methods.According to the requirement in the existing digital oscilloscope calibrating standard of country, calibration steps is as follows:
1) the oscilloscope calibrator output frequency is the sine wave signal of 50kHz, and the amplitude of fine setting prover makes the waveform on the digital oscilloscope screen be shown as whole 6 lattice.
2) keep the amplitude of oscilloscope calibrator output signal constant, increase output signal frequency gradually, the waveform height that shows on the digital oscilloscope screen reduces gradually, up to it highly just in time is 4.2 lattice, just original 6 lattice-the 3dB place, then the frequency values that shows on the oscilloscope calibrator this moment is the frequency span of digital oscilloscope.
The method adopts manually to be not difficult to realize.But the calibration realization is quite difficult fully automatically with computing machine, and nobody can accomplish at present.In native system, under computer control, can send two parameters of signal to oscilloscope calibrator: frequency f and amplitude Uf control, signal inputs to oscillograph, simultaneously instant according to digital oscilloscope amplitude reading is adjusted the size of oscilloscope calibrator output signal frequency, the reading of constantly adjusting frequency automatically, thereby the range value that finds digital oscilloscope test drops on-Frequency point at 3dB place, and as the measured value of digital oscilloscope frequency span.If oscilloscope calibrator has disposed a plurality of active probes, then can be to multiple-channel digital oscilloscope calibration automatically simultaneously.
The step of full-automatic calibration digital oscilloscope frequency span method is as follows: by the computer control oscilloscope calibrator to being provided with and calibrating by the school digital oscilloscope: oscilloscope calibrator sends two parameters of signal: frequency f and amplitude U
fInput to by each passage input end of school digital oscilloscope, detect the reading of amplitude simultaneously according to digital oscilloscope, adjust the size of oscilloscope calibrator output signal frequency at any time automatically.When signal frequency f is the 50kHz reference frequency, need holding frequency constant, fine setting range value U
f, making the waveform that shows on the digital oscilloscope screen is whole 6 lattice, at this moment the range value U at correspondence-3dB place
F0Oscilloscope calibrator sends frequency about the analog frequency band width range that digital oscilloscope is demarcated, and the maintenance amplitude is constant, the value of adjusting frequency, and frequency values of every change simultaneously, oscillograph is all measured present range value automatically, with U
F0Compare, if greater than U
F0, then increase frequency, if less than U
F0, then reduce frequency, through repeatedly comparing, make the range value of digital oscilloscope waveform just in time be U
F0At this moment, the Frequency point of this moment being preserved, both has been exactly this oscillographic bandwidth measured value.If certainly the waveform that shows is straight for being other amplitude, the range value U at this moment corresponding different dB place
F0Because-3dB is the requirement on the standard, so there is this to choose.
Said method constitutes the process of search automatically by the measurement of frequency sweep and range value, for the realization system searches satisfactory Frequency point automatically, being provided with multi-level frequency judges interval, and carry out nested loop search, through test of many times, it is interval to be provided with rational judgement, simultaneously all right recycle back, recycle back and forward circulation acting in conjunction can make things convenient for to search certain satisfactory Frequency point accurately automatically.Through the too much test of platform digital oscilloscope, system performance is stable, and data repeatability is also relatively good.
Improvement of the present invention is: the calibration of trigger sensitivity: utilize the automatic measurement function of digital oscilloscope, judge that can tested waveform meet the demands.The vertical shelves level of digital oscilloscope is set to the 500mV/ lattice, oscilloscope calibrator output amplitude value is the sine wave signal of 500mV, regulate the horizontal scanning setting of digital oscilloscope, make the waveform can steady display, the range value of fine setting oscilloscope calibrator output signal, simultaneously, gather digital oscilloscope range value measured value, compare, if greater than the sine wave signal of 500mV with 500mV, feed back to computing machine: oscilloscope calibrator amplitude output signal value is excessive, computing machine sends instruction, and oscilloscope calibrator fine setting range value is further reduced, otherwise, then increasing, just in time is 500mV up to the range value of the waveform of digital oscilloscope screen display.
The principle of work of digital oscilloscope automated calibration system: after setting instrument address separately, send program control instruction by gpib interface, prover and carried out every setting in view of the above in phase by the school digital oscilloscope by control computer.Under computer control, send various calibration desired signals by prover and deliver to each passage input end of oscillograph, carry out the calibration of parameters.Test data is uploaded to control computer through gpib bus, data is handled again and calibration result is printed by computing machine, thereby finish the calibration of digital oscilloscope.
The invention has the beneficial effects as follows: by proposing a kind of calibrating and measuring method and automated calibration system of digital oscilloscope, can be fully according to " JJG262-1996, the analog oscilloscope vertification regulation ", the requirement of " JJF1057-1998 digital oscilloscope calibrating standard " etc., the digital oscilloscope frequency span is automatically calibrated.In the full-automatic calibration system of digital oscilloscope, can carry out selftest (Self Test) to digital oscilloscope; Trigger sensitivity (comprising internal trigger and external trigger); The DC current gain accuracy of measurement; The square wave accuracy of measurement; Frequency span; Bandwidth constraints; Transient response; The calibration operation of long period and a plurality of projects of scanning accuracy etc. time delay, calibration is according to meeting " JJG262-1996, analog oscilloscope vertification regulation ", " JJF1057-1998 digital oscilloscope calibrating standard " and " TDS3000B series digit oscillograph technical specification " fully.Can automatically calibrate the digital oscilloscope frequency span, this is the innovative point of native system.Calibration steps of the present invention is innovated to some extent, not only can calibrate the square wave accuracy of measurement according to the method for traditional analog oscilloscope, frequency span, trigger sensitivity and transient response, also can be according to the characteristic of digital oscilloscope, parameters such as DC current gain accuracy, long period and delay time measurement accuracy are calibrated, both comprise the calibration point that is embodied in the oscillograph conventional calibration method, increased outstanding its digitized calibration item again.In conjunction with the calibrating of trigger sensitivity, utilize the automatic measurement function of digital oscilloscope simultaneously, can efficiently finish the calibrating and measuring of the leading indicator of digital oscilloscope.
Description of drawings:
Fig. 1 is a measurement mechanism synoptic diagram of the present invention:
Fig. 2 is the calibration schematic flow sheet
Embodiment:
According to above-mentioned calibration steps, the present invention adopts the MET/CAL language to programme.The MET/CAL language is the Laboratory Instruments control and management platform that the FLUKE of U.S. instrument and meter production company develops voluntarily, it satisfies the ISO9000 system, American National Standard ANSIZ540, the requirement of ISO17025 Laboratory Accreditation guide rule and other quality governing principle and standard, it provides a very powerful platform to the user, can be on this platform base, develop the automatic calibration procedure that is fit to a lot of calibrating devices, be used for table of logarithm or oscillograph or other various digital measurement instruments detect.Measurement update software of the present invention is made of three parts: database, testing software, report tool.That database adopts is Sybase SQL anywhere 8, testing software partly is made up of MET_CAL Run Time, MET_CAL Track and MET_CALEditor etc., test subject is MET_CAL Run time, the instrument of management laboratory equipment is MET_CALTrack, the instrument that is used for developing programming is MET_CAL Editor, and report tool is to adopt Crystal Reports 10.Wherein, MET_CAL Run Time carries out the calibration procedure step as shown in Figure 2: at first option program carries out pre-calibration, calibrates preparation according to the detection step and judge after the equipment that obtains is confirmed, calibrates when calibration is ready to complete then, thereby obtains calibration data; Then detect the step operation again when calibrating to prepare not finish.The calibration foundation: the present invention is based on " JJF1057-1998 digital oscilloscope calibrating standard ", with reference to " JJG262-1996, the analog oscilloscope vertification regulation " the correlation technique index, and use for reference " TDS3000B series digit oscillograph technical specification " calibration steps, as the calibration foundation.System configuration such as Fig. 1: the digital oscilloscope automated calibration system comprises PC, oscilloscope calibrator 9500B, gpib interface module, GPIB line, by school digital oscilloscope, digital oscilloscope communication interface modules etc.The 9500B type oscilloscope calibrator that oscilloscope calibrator adopts U.S. FLUKE company to produce, stable performance, can send the various signals that are used for calibrated oscilloscope, precision and accuracy all can reach level leading in the oscilloscope calibrator, the active probe that is equipped with can guarantee that signal can not distort when being connected to oscillographic input end, is fit to the auto-calibration oscillograph.The present invention has been equipped with specially and has been applicable to the oscillographic GPIB communication interface modules of TDS3000/TDS3000B series digit TDS3GV option, is used for digital oscilloscope and compunication.
Claims (3)
1. the calibrating and measuring method of digital oscilloscope frequency span, it is characterized in that by the computer control oscilloscope calibrator being provided with and calibrating by the school digital oscilloscope: the control oscilloscope calibrator sends signal, i.e. frequency f and amplitude U
fSignal input to by each passage input end of school digital oscilloscope, detect simultaneously the reading of amplitude according to digital oscilloscope, adjust the size of oscilloscope calibrator output signal frequency at any time automatically; When signal frequency f was the 50kHz reference frequency, holding frequency was constant, fine setting range value U
f, making the waveform that shows on the digital oscilloscope screen is whole 6 lattice, at this moment the range value U at correspondence-3dB place
F0, oscilloscope calibrator sends frequency about the analog frequency band width range that digital oscilloscope is demarcated, and the maintenance amplitude is constant, the value of adjusting frequency, frequency values of every change simultaneously, oscillograph is all measured present range value automatically, with U
F0Compare, if greater than U
F0, then increase frequency, if less than U
F0, then reduce frequency, through repeatedly comparing, make the range value of digital oscilloscope waveform just in time be U
F0At this moment, the Frequency point of this moment being preserved, both has been exactly this oscillographic bandwidth measured value.
2. the calibrating and measuring method of digital oscilloscope according to claim 1, it is characterized in that the measurement interval by frequency sweep and range value of described frequency and range value searches for automatically, for the realization system searches satisfactory Frequency point automatically, be provided with multi-level frequency separation, and carry out nested loop search, determine that the reasonable frequency judgement is interval, recycle back and forward circulation acting in conjunction simultaneously, convenient certain satisfactory Frequency point that searches automatically accurately.
3. the calibrating and measuring method of digital oscilloscope according to claim 1, needing it is characterized in that digital oscilloscope is carried out the trigger sensitivity calibrating, the calibration method of trigger sensitivity is: utilize the automatic measurement function of digital oscilloscope, the vertical shelves level of digital oscilloscope is set to the 500mV/ lattice, oscilloscope calibrator output amplitude value is the sine wave signal of 500mV, regulate the horizontal scanning setting of digital oscilloscope, waveform stabilization is shown, the range value of fine setting oscilloscope calibrator output signal, simultaneously, gather digital oscilloscope range value measured value, compare with 500mV, if the sine wave signal greater than 500mV feeds back to computing machine: computing machine sends instruction, oscilloscope calibrator fine setting range value is reduced; Otherwise, then increase oscilloscope calibrator fine setting range value, just in time be 500mV up to the range value of the waveform of digital oscilloscope screen display.
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|---|---|---|---|---|
| CN101685107B (en) * | 2008-09-23 | 2011-08-10 | 王悦 | Testing device with setting state converting function and control method thereof |
| CN102043138B (en) * | 2009-10-23 | 2014-03-26 | 鸿富锦精密工业（深圳）有限公司 | System and method for calibrating channel of oscilloscope |
| CN102096056A (en) * | 2009-12-09 | 2011-06-15 | 无锡爱睿芯电子有限公司 | Method for automatically correcting sound card oscilloscope |
| CN102495387B (en) * | 2011-12-21 | 2013-10-23 | 北京航天测控技术有限公司 | Method for automatically calibrating direct current accuracy of digital oscilloscope on basis of binary search |
| CN102749604B (en) * | 2012-06-27 | 2015-11-25 | 北京泛华恒兴科技有限公司 | Testing apparatus automatic calibrator, calibration system and calibration steps |
| CN103076479B (en) * | 2013-01-24 | 2015-02-18 | 福建利利普光电科技有限公司 | Control method of closed-loop correction signal of oscilloscope |
| CN104678338A (en) * | 2015-02-10 | 2015-06-03 | 深圳市鼎阳科技有限公司 | Digital oscilloscope, self checking method and automatic test system |
| CN106569162B (en) * | 2016-10-17 | 2019-04-02 | 深圳市鼎阳科技有限公司 | A kind of the analog bandwidth measurement method and device of logic analyser probe |
| CN106501743B (en) * | 2016-12-07 | 2019-04-19 | 广州致远电子股份有限公司 | A kind of digital oscilloscope accuracy calibrating method and device |
| CN111044962B (en) * | 2019-12-26 | 2022-07-08 | 北京航天测控技术有限公司 | Bandwidth flatness calibration method based on FFT |
| CN111856374B (en) * | 2020-08-27 | 2022-11-29 | 西安微电子技术研究所 | High-speed digital oscilloscope bandwidth calibration testing device and testing method |
| CN115219971B (en) * | 2022-06-30 | 2024-01-23 | 苏州浪潮智能科技有限公司 | Oscillograph waveform checking method, oscillograph waveform checking device, oscillograph waveform checking equipment and oscillograph waveform checking storage medium |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1203432C (en) * | 2002-04-16 | 2005-05-25 | 北京工业大学 | Phase information recoverable sweep frequency source method |
| CN1818670A (en) * | 2006-01-24 | 2006-08-16 | 北京工业大学 | Method and device for calibrating wide-band sampling oscillograph |
| CN1937429A (en) * | 2006-08-09 | 2007-03-28 | 哈尔滨工业大学 | Method for estimating wide-band harmonic phase and its indeterminacy based on NTN calibration |
-
2007
- 2007-09-29 CN CN 200710094127 patent/CN101131419B/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1203432C (en) * | 2002-04-16 | 2005-05-25 | 北京工业大学 | Phase information recoverable sweep frequency source method |
| CN1818670A (en) * | 2006-01-24 | 2006-08-16 | 北京工业大学 | Method and device for calibrating wide-band sampling oscillograph |
| CN1937429A (en) * | 2006-08-09 | 2007-03-28 | 哈尔滨工业大学 | Method for estimating wide-band harmonic phase and its indeterminacy based on NTN calibration |
Non-Patent Citations (2)
| Title |
|---|
| 李梅，刘慧芳，沈海鸿.改进的扫频源校准法.《中国仪器仪表》.2004,(第2期),10-11. * |
| 陈曦,李庄伟.关于数字示波器电压测量准确度校准方法研究.《上海计量测试》.2006,(第5期),30-33. * |
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