CN102928662A - Method and device for measuring signal frequency stability - Google Patents
Method and device for measuring signal frequency stability Download PDFInfo
- Publication number
- CN102928662A CN102928662A CN2012104282525A CN201210428252A CN102928662A CN 102928662 A CN102928662 A CN 102928662A CN 2012104282525 A CN2012104282525 A CN 2012104282525A CN 201210428252 A CN201210428252 A CN 201210428252A CN 102928662 A CN102928662 A CN 102928662A
- Authority
- CN
- China
- Prior art keywords
- frequency
- source
- measurement
- tested
- unusually
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 16
- 238000005259 measurement Methods 0.000 claims abstract description 108
- 238000001514 detection method Methods 0.000 claims abstract description 50
- 238000010009 beating Methods 0.000 claims description 51
- 239000013078 crystal Substances 0.000 claims description 9
- 238000012545 processing Methods 0.000 claims description 9
- 238000000691 measurement method Methods 0.000 claims description 8
- 238000012217 deletion Methods 0.000 claims description 6
- 230000037430 deletion Effects 0.000 claims description 6
- 238000012544 monitoring process Methods 0.000 claims description 4
- 229910052792 caesium Inorganic materials 0.000 claims description 3
- TVFDJXOCXUVLDH-UHFFFAOYSA-N caesium atom Chemical compound [Cs] TVFDJXOCXUVLDH-UHFFFAOYSA-N 0.000 claims description 3
- 229910052739 hydrogen Inorganic materials 0.000 claims description 2
- 239000001257 hydrogen Substances 0.000 claims description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims 1
- 230000002159 abnormal effect Effects 0.000 abstract 6
- 230000007774 longterm Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 230000005670 electromagnetic radiation Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 125000004435 hydrogen atom Chemical group [H]* 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
Images
Landscapes
- Measuring Frequencies, Analyzing Spectra (AREA)
Abstract
The invention discloses a method and a device for measuring signal frequency stability and belongs to the field of atomic frequency standards. The method comprises the following steps of: adopting a first frequency measurement instrument, and simultaneously measuring a measured frequency source and output frequency of a compensation detection source; judging whether an abnormal jump point simultaneously occurs in an output frequency value of the frequency of the measured frequency source and an output frequency value of the compensation detection source; deleting the abnormal jump point in a frequency measurement result of the measured frequency source if the abnormal jump point simultaneously occurs; and calculating the frequency stability of the measured frequency source. Whether the abnormal jump joint simultaneously occurs in the output frequency values in the frequency measurement result of the measured frequency source and the frequency measurement result of the compensation detection source is judged, and when the abnormal jump joint simultaneously occurs, the abnormal jump point in the frequency measurement result of the measured frequency source is deleted, the workload is reduced, and the measurement accuracy of the frequency stability is improved.
Description
Technical field
The present invention relates to the atomic frequency standard field, particularly a kind of frequency stability measurement method and apparatus.
Background technology
Along with the progress of science and technology, the split-second precision frequency is widely used in the various fields such as space flight, communication, and people are also more and more higher to the stability requirement of the frequency output of clock source simultaneously.The normal proportion degree of stability of output signal frequency stability of clock source is weighed.
At present, the frequency stability measurement of clock source need to be finished by means of counter or than equipment such as phase instrument and external reference sources usually.Wherein, be a kind of High Speed High Accuracy Frequency Measurement device than phase instrument, it is to compare by the phase place to two frequency standard output signals, measures the average frequency deviation of these two signals, calculates thus frequency stability.
In realizing process of the present invention, the inventor finds that there is following problem at least in prior art:
When measuring the frequency stability of clock source by prior art, measurement data exists some and unusually beats a little, unusually beat a little for these, need to when measuring, use other supplementary meanss to judge, as judging that by temperature survey unusually beating a little is that tested frequency source causes itself, or caused by surveying instrument or external reference source, deleting these in the later stage by software according to judged result unusually beats and a little solves problem, this deletion mode can increase burden to surveying work, and this judgment mode deletion that probably makes the mistake, when deleted unusually beating a little comprise by measured clock be derived from that the reason of body causes unusually beat some the time, also can cause measuring error.
Summary of the invention
In order to solve the problem of prior art, the embodiment of the invention provides a kind of signal frequency stable measurement method and apparatus.Described technical scheme is as follows:
On the one hand, the embodiment of the invention provides a kind of signal frequency stable measurement method, and described method comprises:
Two frequency signal sources are provided, and one of them described frequency signal source is as external reference source, and another described frequency signal source is detection resources by way of compensation;
Adopt the first frequency surveying instrument, measure simultaneously the output frequency of tested frequency source and described compensation detection resources, obtain the frequency measurement of described tested frequency source and the frequency measurement of described compensation detection resources, described first frequency surveying instrument adopts described external reference source as the external clock reference;
Judge whether the output frequency value in the frequency measurement of the frequency measurement of described tested frequency source and described compensation detection resources occurs unusually beating a little simultaneously;
If unusually beating a little appears in output frequency value in the frequency measurement of the frequency measurement of described tested frequency source and described compensation detection resources simultaneously, delete described unusually the beating a little in the frequency measurement of described tested frequency source;
According to the frequency measurement of the described described tested frequency source after unusually beating a little of deletion, calculate the frequency stability of described tested frequency source.
Further, described method also comprises:
Adopt the second frequency surveying instrument to measure the output frequency of described tested frequency source;
Unusually beating a little appears in the output frequency value in the frequency measurement of described tested frequency source, and the output frequency value in the frequency measurement of described compensation detection resources is when occurring simultaneously unusually beating, and the frequency measurement that the frequency measurement that described second frequency surveying instrument is measured and first frequency surveying instrument measure averages.
Further, described second frequency surveying instrument selects crystal oscillator as the external clock reference.
Further, described method also comprises: the working environment information of measuring described tested frequency source.
On the other hand, the embodiment of the invention also provides a kind of signal frequency stable measurement device, and described device comprises:
The compensation detection resources;
The first frequency surveying instrument, the output frequency for measuring tested frequency source and described compensation detection resources obtains the frequency measurement of described tested frequency source and the frequency measurement of described compensation detection resources;
External reference source is used to described first frequency surveying instrument that the external clock reference is provided;
Central processing unit is used for judging whether the output frequency value of the frequency measurement of the frequency measurement of described tested frequency source and described compensation detection resources occurs unusually beating a little simultaneously; If unusually beating a little appears in output frequency value in the frequency measurement of the frequency measurement of described tested frequency source and described compensation detection resources simultaneously, then delete described unusually the beating a little in the frequency measurement of described tested frequency source; According to the frequency measurement of the described described tested frequency source after unusually beating a little of deletion, calculate the frequency stability of described tested frequency source.
Further, described device also comprises:
The second frequency surveying instrument is for the output frequency of measuring described tested frequency source;
Crystal oscillator is used to described second frequency surveying instrument that the external clock reference is provided;
Unusually beating a little appears in the output frequency value that described central processing unit also is used for the frequency measurement of described tested frequency source, and the output frequency value in the frequency measurement of described compensation detection resources is when occurring simultaneously unusually beating, and the frequency measurement that the frequency measurement that described second frequency surveying instrument is measured and first frequency surveying instrument measure averages.
Further, described device also comprises: environment monitoring module, and for the working environment information of measuring tested frequency source.
Further, described first frequency surveying instrument is counter or than phase instrument.
Further, described external reference source is hydrogen clock, caesium clock or GPS time signal.
The beneficial effect that the technical scheme that the embodiment of the invention provides is brought is:
Whether occur simultaneously unusually beating a little by the output frequency value in the frequency measurement of judging tested frequency source and the frequency measurement that compensates detection resources, and unusually to beat a little appear in output frequency value in the frequency measurement of the frequency measurement of tested frequency source and compensation detection resources simultaneously, deletes unusually beating a little in the frequency measurement of tested frequency source; Therefore, only accomplished unusually beating of being caused by surveying instrument or external reference source a little deleted, not only reduced workload, improved simultaneously the measuring accuracy of frequency stability.
Description of drawings
In order to be illustrated more clearly in the technical scheme in the embodiment of the invention, the accompanying drawing of required use was done to introduce simply during the below will describe embodiment, apparently, accompanying drawing in the following describes only is some embodiments of the present invention, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain according to these accompanying drawings other accompanying drawing.
Fig. 1 is a kind of signal frequency stable measurement method flow diagram that the embodiment of the invention one provides;
Fig. 2 is a kind of signal frequency stable measurement apparatus structure schematic diagram that the embodiment of the invention two provides.
Embodiment
For making the purpose, technical solutions and advantages of the present invention clearer, embodiment of the present invention is described further in detail below in conjunction with accompanying drawing.
Embodiment one
The embodiment of the invention provides a kind of signal frequency stable measurement method, and referring to Fig. 1, the method comprises:
Step 101: two frequency signal sources are provided, and one of them frequency signal source is as external reference source, and another frequency signal source is detection resources by way of compensation.
Particularly, this external reference source can be selected the higher high stability atomic clock of long-term stability, such as the H(hydrogen atom) clock, Cs(caesium atom) clock etc., or GPS(Global Positioning System, GPS) time signal.
Step 102: adopt the first frequency surveying instrument, measure simultaneously the output frequency of tested frequency source and compensation detection resources, obtain the frequency measurement of tested frequency source and the frequency measurement of compensation detection resources, the first frequency surveying instrument adopts external reference source as the external clock reference.
Wherein, the first frequency surveying instrument can be selected existing time-domain measurement technique multimeter, such as high-resolution counter or than devices such as Xiang Yi.
What deserves to be explained is, tested frequency source is frequency signal source with the compensation detection resources, in assessment during tested frequency source Stability index, needs to select same level or high-level signal source detection resources by way of compensation in tested frequency source.
Step 103: judge that whether unusually beating a little appears in output frequency value in the frequency measurement of the frequency measurement of tested frequency source and compensation detection resources simultaneously.
Particularly, this step can comprise:
When the output frequency value in the frequency measurement of a certain tested frequency source of the moment occurs unusually beating, judge whether the output frequency value in the frequency measurement of compensation detection resources occurs unusually beating a little simultaneously; If occur, represent that then first frequency surveying instrument or external reference source go wrong; If do not occur, illustrate that then tested frequency source goes wrong.
So-called " unusually beating a little " refers to that larger fluctuation appears in certain point in the output frequency value in the frequency measurement, as: the output frequency of a tested frequency source is 5E-12/ second, and a certain moment test result shows that output frequency is 5E-11/ second.
Step 104: if unusually beating a little appears in output frequency value in the frequency measurement of the frequency measurement of tested frequency source and compensation detection resources simultaneously, delete unusually beating a little in the frequency measurement of tested frequency source.
Step 105: the frequency measurement of the tested frequency source after beating a little according to suppressing exception, calculate the frequency stability of tested frequency source.
In specific implementation, this step 103 ~ 105 can be by realizations such as central processing unit, single-chip microcomputer, microcontrollers.
Further, the method also comprises: the working environment information of measuring tested frequency source.When unusually beating in the output frequency value of tested frequency source is a little excessive, need to overhaul according to the working environment information of tested frequency source, for example the output frequency of a tested frequency source is 1E-12/ second, a certain moment test result shows that output frequency is 1E-10/ second or larger, thinks that then this tested frequency source need to overhaul.Above-mentioned working environment information is detected by an independent module, to the working environment information and be presented among the detecting information result.Make things convenient for the scientific research personnel to check fault.
Working environment information comprises: the parameter values such as temperature, humidity, electromagnetic radiation level, time.Correspondingly, working environment information can adopt the devices such as temperature sensor, humidity sensor to obtain.
Preferably, the method also comprises:
Adopt the second frequency surveying instrument to measure the output frequency of tested frequency source;
When the output frequency value in the frequency measurement of compensation detection resources occurs unusually beating simultaneously:
Calculate the frequency stability of tested frequency source according to the output frequency value that measures;
The frequency measurement that the frequency measurement that the second frequency surveying instrument is measured and first frequency surveying instrument measure averages.
Correspondingly, at this moment the frequency stability of tested frequency source is calculated according to the frequency measurement after average.
Wherein, the second frequency surveying instrument selects high stability crystal oscillator as the external clock reference.What deserves to be explained is, generally can choose the higher time source of long-term stability among the present invention as the external reference source of first frequency surveying instrument, select high stability crystal oscillator as the external clock reference of second frequency surveying instrument.When hop appears in tested frequency source, enable the frequency measurement of second frequency surveying instrument, brought into play the advantage of high stability crystal oscillator in short-term stability, and when hop does not appear in tested frequency source, enable the frequency measurement of first frequency surveying instrument, brought into play the advantage of external reference source aspect long-term stability.
Need to prove, when tested frequency source does not occur unusually beating, directly record the measurement result of first frequency surveying instrument.
Whether the embodiment of the invention occurs unusually beating a little by the output frequency value in the frequency measurement of judging tested frequency source and the frequency measurement that compensates detection resources simultaneously, and unusually to beat a little appear in output frequency value in the frequency measurement of the frequency measurement of tested frequency source and compensation detection resources simultaneously, deletes unusually beating a little in the frequency measurement of tested frequency source; Therefore, only accomplished unusually beating of being caused by surveying instrument or external reference source a little deleted, not only reduced workload, improved simultaneously the measuring accuracy of frequency stability.
Embodiment two
The embodiment of the invention provides a kind of signal frequency stable measurement device, and referring to Fig. 2, this device comprises:
First frequency surveying instrument 203, the output frequency that is used for measuring tested frequency source 201 and compensates detection resources 207 obtains the frequency measurement of tested frequency source 201 and the frequency measurement of compensation detection resources 207;
Further, this device also comprises:
Second frequency surveying instrument 206 is for the output frequency of measuring tested frequency source 201;
Further, this device also comprises, environment monitoring module 208 is for the working environment information of measuring tested frequency source 201.
First frequency surveying instrument 203 is counter or than phase instrument.
Tested frequency source 201 is frequency signal source with compensation detection resources 207, is noted that: when the tested frequency source Stability index of assessment, need to select same level or high-level signal source detection limit source by way of compensation in tested frequency source.
Simultaneously tested frequency source 201 signals are also delivered to crystal oscillator and are made the second frequency surveying instrument 206 of 205 external clock references and carry out frequency measurement.
The frequency measurement of first frequency surveying instrument 203 is all delivered to central processing unit 204 and is processed by time domain frequency stability calculating standard, calculates the frequency stability of tested frequency source 201 as adopting Allan variance.Central processing unit 204 gathers the information (comprising the parameter values such as temperature, humidity, electromagnetic radiation level, time) that environment monitoring module 208 obtains simultaneously.
Whether the embodiment of the invention occurs unusually beating a little by the output frequency value in the frequency measurement of judging tested frequency source and the frequency measurement that compensates detection resources simultaneously, and unusually to beat a little appear in output frequency value in the frequency measurement of the frequency measurement of tested frequency source and compensation detection resources simultaneously, deletes unusually beating a little in the frequency measurement of tested frequency source; Therefore, only accomplished unusually beating of being caused by surveying instrument or external reference source a little deleted, not only reduced workload, improved simultaneously the measuring accuracy of frequency stability.
The all or part of step that one of ordinary skill in the art will appreciate that realization above-described embodiment can be finished by hardware, also can come the relevant hardware of instruction to finish by program, described program can be stored in a kind of computer-readable recording medium, the above-mentioned storage medium of mentioning can be ROM (read-only memory), disk or CD etc.
The above only is preferred embodiment of the present invention, and is in order to limit the present invention, within the spirit and principles in the present invention not all, any modification of doing, is equal to replacement, improvement etc., all should be included within protection scope of the present invention.
Claims (9)
1. a signal frequency stable measurement method is characterized in that, described method comprises:
Two frequency signal sources are provided, and one of them described frequency signal source is as external reference source, and another described frequency signal source is detection resources by way of compensation;
Adopt the first frequency surveying instrument, measure simultaneously the output frequency of tested frequency source and described compensation detection resources, obtain the frequency measurement of described tested frequency source and the frequency measurement of described compensation detection resources, described first frequency surveying instrument adopts described external reference source as the external clock reference;
Judge whether the output frequency value in the frequency measurement of the frequency measurement of described tested frequency source and described compensation detection resources occurs unusually beating a little simultaneously;
If unusually beating a little appears in output frequency value in the frequency measurement of the frequency measurement of described tested frequency source and described compensation detection resources simultaneously, then delete described unusually the beating a little in the frequency measurement of described tested frequency source;
According to the frequency measurement of the described described tested frequency source after unusually beating a little of deletion, calculate the frequency stability of described tested frequency source.
2. method according to claim 1 is characterized in that, described method also comprises:
Adopt the second frequency surveying instrument to measure the output frequency of described tested frequency source;
Unusually beating a little appears in the output frequency value in the frequency measurement of described tested frequency source, and the output frequency value in the frequency measurement of described compensation detection resources is when occurring simultaneously unusually beating, and the frequency measurement that the frequency measurement that described second frequency surveying instrument is measured and first frequency surveying instrument measure averages.
3. method according to claim 2 is characterized in that, described second frequency surveying instrument selects crystal oscillator as the external clock reference.
4. method according to claim 1 is characterized in that, described method also comprises: the working environment information of measuring described tested frequency source.
5. a signal frequency stable measurement device is characterized in that, described device comprises:
Compensation detection resources (207);
First frequency surveying instrument (203), be used for measuring the output frequency of tested frequency source (201) and described compensation detection resources (207), obtain the frequency measurement of described tested frequency source (201) and the frequency measurement of described compensation detection resources (207);
External reference source (202) is used to described first frequency surveying instrument (203) that the external clock reference is provided;
Central processing unit (204) is used for judging whether the output frequency value of the frequency measurement of the frequency measurement of described tested frequency source (201) and described compensation detection resources (207) occurs unusually beating a little simultaneously; If unusually beating a little appears in output frequency value in the frequency measurement of the frequency measurement of described tested frequency source (201) and described compensation detection resources (207) simultaneously, delete described unusually the beating a little in the frequency measurement of described tested frequency source (201); According to the frequency measurement of the described described tested frequency source (201) after unusually beating a little of deletion, calculate the frequency stability of described tested frequency source (201).
6. device according to claim 5 is characterized in that, described device also comprises:
Second frequency surveying instrument (206) is for the output frequency of measuring described tested frequency source (201);
Crystal oscillator (205) is used to described second frequency surveying instrument (206) that the external clock reference is provided;
Described central processing unit (204) also is used for occurring unusually beating a little when the output frequency value of the frequency measurement of described tested frequency source (201), and the output frequency value in the frequency measurement of compensation detection resources (207) is when occurring simultaneously unusually beating, and the frequency measurement that the frequency measurement that described second frequency surveying instrument (206) is measured and first frequency surveying instrument (203) measure averages.
7. device according to claim 5 is characterized in that, described device also comprises: environment monitoring module (208), and for the working environment information of measuring described tested frequency source (201).
8. device according to claim 5 is characterized in that, described first frequency surveying instrument (203) is counter or than phase instrument.
9. device according to claim 5 is characterized in that, described external reference source (202) is hydrogen clock, caesium clock or GPS time signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210428252.5A CN102928662B (en) | 2012-10-31 | 2012-10-31 | Method and device for measuring signal frequency stability |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210428252.5A CN102928662B (en) | 2012-10-31 | 2012-10-31 | Method and device for measuring signal frequency stability |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102928662A true CN102928662A (en) | 2013-02-13 |
| CN102928662B CN102928662B (en) | 2015-02-04 |
Family
ID=47643508
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210428252.5A Expired - Fee Related CN102928662B (en) | 2012-10-31 | 2012-10-31 | Method and device for measuring signal frequency stability |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102928662B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104407510A (en) * | 2014-11-17 | 2015-03-11 | 江汉大学 | Method and device for time service |
| CN107102203A (en) * | 2017-06-15 | 2017-08-29 | 江汉大学 | A kind of measuring method and measurement apparatus |
| CN111123083A (en) * | 2019-12-06 | 2020-05-08 | 国家电网有限公司 | Test system and method for FPGA PLL IP core |
| CN112485517A (en) * | 2020-09-28 | 2021-03-12 | 中国电子科技集团公司第十三研究所 | Method for measuring frequency hopping time of phase-locked frequency source and terminal equipment |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3725781A (en) * | 1971-03-17 | 1973-04-03 | Dranetz Eng Labor Inc | Phase meter with noise error reduction means |
| JPS5013104B1 (en) * | 1970-09-11 | 1975-05-16 | ||
| US4710702A (en) * | 1985-04-13 | 1987-12-01 | Anritsu Corporation | Heterodyne type signal-measuring method and a measuring apparatus including automatic detuning correction means |
| JPH07142971A (en) * | 1993-11-18 | 1995-06-02 | Fujitsu Ltd | Noise eliminating device and period measuring unit |
| CN1382995A (en) * | 2002-04-24 | 2002-12-04 | 清华大学 | Digital measuring method of frequency and phase |
| JP2006038485A (en) * | 2004-07-22 | 2006-02-09 | Anritsu Corp | Frequency stability measuring instrument |
| JP2011232143A (en) * | 2010-04-27 | 2011-11-17 | Seiko Epson Corp | Frequency detection device and physical quantity sensor |
-
2012
- 2012-10-31 CN CN201210428252.5A patent/CN102928662B/en not_active Expired - Fee Related
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5013104B1 (en) * | 1970-09-11 | 1975-05-16 | ||
| US3725781A (en) * | 1971-03-17 | 1973-04-03 | Dranetz Eng Labor Inc | Phase meter with noise error reduction means |
| US4710702A (en) * | 1985-04-13 | 1987-12-01 | Anritsu Corporation | Heterodyne type signal-measuring method and a measuring apparatus including automatic detuning correction means |
| JPH07142971A (en) * | 1993-11-18 | 1995-06-02 | Fujitsu Ltd | Noise eliminating device and period measuring unit |
| CN1382995A (en) * | 2002-04-24 | 2002-12-04 | 清华大学 | Digital measuring method of frequency and phase |
| JP2006038485A (en) * | 2004-07-22 | 2006-02-09 | Anritsu Corp | Frequency stability measuring instrument |
| JP2011232143A (en) * | 2010-04-27 | 2011-11-17 | Seiko Epson Corp | Frequency detection device and physical quantity sensor |
Non-Patent Citations (3)
| Title |
|---|
| NIMA AMJADY ET AL.: "Determination of frequency stability border of power system to set the thresholds of under frequency load shedding relays", 《ENERGY CONVERSION AND MANAGEMENT》, vol. 51, 31 December 2010 (2010-12-31), pages 1864 - 1872, XP027057098 * |
| 孙素霞 等: "基于等效鉴相频率的频率稳定度的检测方法", 《仪器与仪表》, no. 201, 31 October 2005 (2005-10-31), pages 10 - 11 * |
| 甘晓翠 等: "频率稳定度的测量", 《信息技术》, no. 6, 30 June 2008 (2008-06-30), pages 121 - 123 * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104407510A (en) * | 2014-11-17 | 2015-03-11 | 江汉大学 | Method and device for time service |
| CN104407510B (en) * | 2014-11-17 | 2017-12-15 | 江汉大学 | A kind of method and apparatus of time service |
| CN107102203A (en) * | 2017-06-15 | 2017-08-29 | 江汉大学 | A kind of measuring method and measurement apparatus |
| CN111123083A (en) * | 2019-12-06 | 2020-05-08 | 国家电网有限公司 | Test system and method for FPGA PLL IP core |
| CN111123083B (en) * | 2019-12-06 | 2022-04-29 | 国家电网有限公司 | Test system and method for FPGA PLL IP core |
| CN112485517A (en) * | 2020-09-28 | 2021-03-12 | 中国电子科技集团公司第十三研究所 | Method for measuring frequency hopping time of phase-locked frequency source and terminal equipment |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102928662B (en) | 2015-02-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN202975155U (en) | Time-domain signal frequency stability measurement device | |
| CN102928662B (en) | Method and device for measuring signal frequency stability | |
| CN101441129A (en) | Optical fiber ring performance measuring and evaluating system based on temperature experiment | |
| CN108571997A (en) | A kind of method and apparatus that measured point is steadily contacted in detection probe | |
| CN115560743A (en) | Error analysis and elimination method and device of fiber-optic gyroscope | |
| CN106569166B (en) | A kind of test method in twin-core electric energy meter legality measurement portion | |
| CN106248044A (en) | A kind of bridge full-bridge Multi-point deflection real-time acquisition and display system | |
| CN103558571A (en) | Calibration system of electronic transformer and merging unit | |
| CN103048106A (en) | Aeroengine vibration transducer double-wire checking and detecting method and implementation system thereof | |
| CN110726852A (en) | MEMS accelerometer temperature compensation method | |
| CN209623725U (en) | A kind of fiber optic coils dynamic simulation test device | |
| CN104457853A (en) | Temperature and humidity measuring meter with correcting function and method for correcting temperature and humidity measuring data | |
| CN103616651A (en) | On-site verification apparatus for optical fiber current sensor | |
| CN107607114A (en) | A kind of digital gyro stabilized platform, the soft test system of online frequency characteristic and method | |
| CN204044245U (en) | A kind of Rb atom frequency marking system signal frequency degree of stability pick-up unit | |
| CN108761161A (en) | A kind of power meter temperature influences error compensating method and device | |
| CN104142299A (en) | Pressure compensation method of infrared methane sensor | |
| CN111025223B (en) | Clock correction method, device, equipment and storage medium of electric energy meter | |
| CN112067165A (en) | Temperature sensor precision testing system, testing method, testing device and storage medium | |
| CN203551762U (en) | Electronic instrument transformer and merging unit verification system | |
| CN103983935A (en) | Indicating instrument detecting system and method | |
| CN110308412A (en) | A kind of method and its system of automatically calibrating electrical high capability instrument instrument | |
| CN109375005A (en) | A kind of number temperature compensating crystal oscillator Auto-Test System and method | |
| CN212391150U (en) | Temperature sensor precision test system | |
| CN210005590U (en) | forward and reverse microwave power measuring circuits |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20150204 |