Some standard content:
National Metrology Verification Regulation of the People's Republic of China JJG488--2008
Watch Tester
Promulgated on 2008-03-25
Implementation on 200809-25
Promulgated by the General Administration of Quality Supervision, Inspection and Quarantine JJG488-2008
Verification Regulation of Watch Tester JJG488--2008
Replaces JJG488
This regulation was approved by the General Administration of Quality Supervision, Inspection and Quarantine on March 25, 2008, and came into effect on September 25, 2008.
Responsible unit: National Technical Committee on Time and Frequency Metrology Main drafting unit: Liaoning Institute of Metrology Participating drafting unit: Shanghai Zhengbiao Metrology and Calibration Technology Co., Ltd. This regulation entrusts the National Technical Committee on Time and Frequency Metrology to be responsible for the interpretation of this regulation Main drafters:
JJG488—2008
Min Xiaoju (Liaoning Institute of Metrology) Sun Jialin (Liaoning Institute of Metrology) Qin Tong (Liaoning Institute of Metrology) Participating drafters:
Zhu Genfu (Shanghai Zhengbiao Metrology and Calibration Technology Co., Ltd.) 2
References·
Overview·
4 Metrology performance requirements
4.1 Metrology performance requirements for crystal oscillator in calibrator, 4.2 Daily error measurement range
Daily error Maximum allowable error of measurement
5 General technical requirements
5.1 Appearance requirements.
5.2 Other requirements·
6 Control of measuring instruments
Verification conditions.
Verification items and verification methods
Processing of verification results
Verification cycle·
Appendix A
Appendix B
JJG488--2008
Verification certificate of calibrator (inside page) format
Selection of calibrator simulator
(1)
1 Scope
JJG488—2008
Verification procedure for calibrator
This procedure applies to the initial verification, subsequent verification and in-use inspection of various calibrators. 2 References
JJF1001-1998 General metrological terms and definitions JJF1059—1999
Evaluation and expression of measurement uncertainty
JJG180—2002 Verification procedures for quartz crystal oscillators in electronic measuring instruments When using this procedure, attention should be paid to using the current valid versions of the above references. 3 Overview
The travel accuracy of various clocks, watches and stopwatches (collectively referred to as clocks) is usually expressed in terms of the rate relative to a standard clock, in units of seconds/day (s/d) or seconds/month (s/month), referred to as daily error or monthly error. The speed of the rate mainly depends on the degree of deviation of the actual value of the frequency of the master oscillator (crystal oscillator for electronic watches and hairspring for mechanical watches) used in the clock from the nominal value, which is called frequency accuracy. The calibrator is used to quickly determine the daily error and monthly error of the clock, and adjust it to achieve a certain required travel accuracy of the calibrated clock.
The method of measuring daily difference by the meter calibrator is to use acoustic, electrical and magnetic sensors to convert the oscillation signal emitted by the clock into a corresponding electrical signal, and use the counting method to measure the deviation of the period of the electrical signal relative to the nominal value, and calculate the daily difference value. The meter calibrator is widely used in watch manufacturers, product quality inspection institutions and metrology verification departments. 4 Metrological performance requirements
4.1 Metrological performance requirements of crystal oscillator in the meter calibrator
4.1.1 Power-on characteristics V: 1×10-6~1×10-84.1.2 Frequency accuracy A: 1×10-5~2×10-4.2 Daily difference measurement range
(0.00~9.99)s/d; (0.0~99.9)s/d; (0~999)s/d. 4.3 Maximum allowable error of daily difference measurement
8: ±0.0ls/d; ±0.1s/d, ±1s/d. 5 General technical requirements
5.1 Appearance requirements
5.1.1 The calibrator shall indicate the manufacturer, model, date of manufacture and serial number. 5.1.2 The switches and buttons of the calibrator shall be flexible and reliable, and the various displays shall be clear and complete. 5.1.3 The appearance of the calibrator shall not have mechanical damage and scratches that affect normal operation. 1
5.2 Other requirements
All functions of the calibrator shall be normal.
Control of measuring instruments
JJG488—2008
Control of measuring instruments includes initial calibration, subsequent calibration and in-use inspection. 6.1 Calibration conditions
6.1.1 Environmental conditions
Lock the payment on the spot
6.1.1.1 Ambient temperature: The temperature change within the range of (20 ± 5) ℃ shall not exceed ± 2 ℃: Relative humidity: 80%. 6.1.1.2 Power supply voltage: 220 (1 ± 1020H power supply frequency S95) Hz 6.1.1.3
6.1.2 Calibration equipment
6.1.2.1 Frequency synthesizer
The accuracy of the internal crystal oscillator frequency should be better than the frequency accuracy of the calibrated meter under test: ≤lμHz.
6.1.2.2 Electronic meter
Measurement frequency range 10
One order of magnitude.
6.1.2.3 Analog
100MHz, the accuracy of the internal crystal oscillator frequency should be better than the standard and frequency synthesis that the calibrated meter can measure.
6.2 Calibration items
6.2.1 Calibration items
See Table 1.
Verification items
Appearance inspection
Functional inspection
Verification method
First verification
Crystal oscillator power-on characteristics
Crystal oscillator frequency accuracy
Daily difference measurement range
Maximum allowable error of daily difference measurement
Analog signal.
Sale calibration
METROLOG
Note 1: "+" indicates mandatory items, "-" indicates optional items Note 2: If the calibrator has no crystal oscillator output signal, the crystal oscillator technical indicators are not inspected Note 3: After repair, the calibrator is subjected to the first calibration 2
Resolution of output frequency
Frequency accuracy
Inspection during use
6.2.2 Calibration method
6.2.2.1 Appearance inspection
JJG488-2008
Use visual inspection and touch to check whether the calibrator complies with Article 5.1 of this Regulation 6.2.2.2 Functional inspection
Operate after power-on and observe that its display should comply with Article 5.2 of this Regulation 6.2.2.3 Calibration of internal crystal oscillator power-on characteristics and frequency accuracy Directly measure the output frequency of the crystal oscillator with an electronic counter. According to the corresponding verification items in the verification procedures for quartz crystal oscillators in electronic measuring instruments JJG1802002, SHOHNH
verification shall be carried out.
6.2.2.4 Daily difference measurement range and allowable measurement error The main oscillator of the calibration instrument is a quartz crystal oscillator.
There are two types of meters that can be measured by the calibration instrument: electronic and mechanical. The instrument is divided into two types: using a pointer dial display and using a pointer dial display: the mechanical main oscillator is a hairspring that produces mechanical oscillations. The instrument connection diagram is shown in the figure. The calibrator is equipped with three types of sensors: electronic type, electromagnetic type, acoustic type, simulator, receiving digital display electronic clock signals, receiving pointer dial display electronic clock signals, receiving mechanical clock signals, and frequency synthesizer. Different simulators are used to generate the corresponding signals received by each sensor. The selection of simulators is shown in Appendix B. Frequency synthesis requires changing the frequency to give the corresponding standard daily and monthly deviations within the measurement range of the calibrator.
（1）Electronic clock
The nominal frequency of the crystal oscillator in the electronic clock is the relationship between the output frequency and the standard daily difference
Frequency synthesis
Calculated according to formula (1
METROEOG
Where: N.
Standard daily difference:
32768Hz
Output frequency of the frequency synthesizer.
The relationship between the output frequency of the frequency synthesizer and the standard monthly difference is calculated according to formula (2): N
2592000
Where: N is the standard monthly difference;
f2 is the output frequency of the frequency synthesizer.
The standard daily difference and standard monthly difference in different measurement ranges and the corresponding frequency values are set according to Table 2 and Table 3. (1)
Daily difference (s/d)
Daily difference (s/d)
JJG488—2008
Table 2 Measurement range (0.00s/d~9.99s/d) Frequency value (Hz)
32768.0189
32768.0379
32768.3793
32769.5170
32770.2756
32771 .4133
32767.9811
32767.9621
32767.6207
32766.4830
32765.7244
32764.5867
Monthly difference (s/month)
Table 3 Measurement range
(0.0s/d~99.9s/d)
Frequency value (Hz)
32 768 | | tt | | 32768.0379 | 32767.9621
32767.810 4
32767.6207
32766.1011
32764.2074
32749.0370
32730.4533
Monthly difference (s/month)
Frequency value (Hz)
32768.0126
32768.0253
32768.0506
32768.0762||t t | 8857
Frequency value (Hz)
32768.0126
32768.0632
32 768.126 4
32768.3793
32768.6321
32769.2642
32767.9876
32767.9368
32767.8736
32767.6207
32767.3679
32766.7358
The measuring time of the calibrator is selected as 10s.
JJG488-2008
Each standard daily difference and standard monthly difference is measured three times, and the arithmetic mean is taken as the measurement result. The measurement error is calculated according to formula (3):
Where: E, the measured average daily difference (or monthly difference); E. ——standard daily difference (or monthly difference); measurement error.
(2) Mechanical clocks
The beat of a mechanical clock is the number of vibrations of the hairspring per hour. The following are commonly used: 7200, 14400, 21600, 28800 and 36000, and the corresponding frequencies are 2Hz, 4Hz, 6Hz, 8Hz and 10Hz respectively. The frequency synthesizer selects 10Hz as the nominal frequency value f3 for generating the standard daily difference. Calculate the output frequency of the frequency synthesizer corresponding to the selected standard daily difference according to formula (4): Nf-fe
Wherein: N. Standard daily difference value;
f3——Frequency value output by the synthesizer when the required daily difference is generated; fo-10Hz. The measurement range of
mechanical meter is generally (0 s/d～999s/d), and the selection of standard daily difference and the corresponding frequency are set according to Table 4.
Table 4 Measurement range (0s/d~999s/d)
Daily difference (s/d)
Frequency value (Hz)
10.000000
10.000116
10.001157
10.003472
Daily difference (s/d)
—600
Frequency value (Hz)
10.000000
JJG488-—2008
Each standard daily difference is measured three times, and the arithmetic mean is taken as the measurement result. The measurement error is calculated according to formula (3).
6.3 Handling of Verification Result
A verification certificate shall be issued for qualified calibrators according to the requirements of this regulation; a verification result notice shall be issued for unqualified calibrators, and the unqualified items shall be indicated.
6.4 Verification Period
The verification period of a calibrator shall generally not exceed 1 year. Appendix A
1. Internal crystal oscillator
Power-on characteristics V=
Frequency accuracy A
2. Measurement error
1. Measuring electronic watches
Standard daily deviation
Standard monthly deviation
2. Measuring mechanical watches
Standard daily deviation
JJG488—2008
Calibration certificate of meter calibrator (inner page) format
Measurement value
Measurement value
Appendix B
JJG488—2008
Selection of meter calibrator simulator
Since meter calibrators are divided into electronic and mechanical types, and the electronic type is further divided into digital display electronic type and pointer electronic type, three different simulators need to be selected during calibration. To calibrate a digital electronic meter calibrator, you only need to place the signal output terminal of the frequency synthesizer on the sensor of the meter calibrator, and the meter calibrator will be able to identify and receive the daily difference signal. To calibrate a pointer electronic meter calibrator, you need to use a pointer electronic watch movement as a simulator, and replace the crystal oscillator inside the movement with the frequency synthesizer output frequency. Put the movement on the sensor of the pointer electronic meter calibrator, and the meter calibrator will be able to identify and receive the daily difference signal.
To calibrate a mechanical meter calibrator, you need to use a piezoelectric ceramic or reed relay as a simulator, and clamp the terminal of the frequency synthesizer on the simulator to make the simulator send out a vibration signal. Put the simulator on the sensor of the meter calibrator, and the meter calibrator will be able to identify and receive the daily difference signal.4533
Monthly difference (s/month)
Frequency value (Hz)
32768.0126
32768.0253
32768.0506
32768.0762||tt ||32768.1016
32768.1143
327 67.9873
32767.9746
32767.9492
32767.9238
32767.8984
32767.8857
Frequency value (Hz)
32768.0126||tt ||32768.0632
32 768.126 4
32768.3793
32768.6321
32769.2642
32767.9876
32767.9368
32767.8736
32767.6207
32767.3679
32766.7358
The measuring time of the calibrator is selected as 10s.
JJG488-2008
Each standard daily difference and standard monthly difference is measured three times, and the arithmetic mean is taken as the measurement result. The measurement error is calculated according to formula (3):
Formula In: E, the average daily difference (or monthly difference) measured; E. —— standard daily difference (or monthly difference); measurement error.
(2) Mechanical clocks||tt ||The beat of a mechanical clock is the number of vibrations of the hairspring per hour. The following are commonly used: 7200, 14400, 21600, 28800 and 36000, and the corresponding frequencies are 2Hz, 4Hz, 6Hz, 8Hz and 10Hz respectively. 10Hz is used as the nominal frequency value f3 for generating the standard daily difference. According to formula (4), the output frequency of the frequency synthesizer corresponding to the selected standard daily difference is calculated: Nf-fe
where: N is the standard daily difference value;
f3 is the frequency synthesizer output frequency corresponding to the selected standard daily difference. The frequency value of the synthesizer output during the daily difference is fo-10Hz.
The measurement range of the mechanical watch is generally (0 s/d～999s/d). The selection of the standard daily difference and the corresponding frequency are set according to Table 4. Certainly.
Table 4 Measurement range (0s/d~999s/d)
Daily difference (s/d)
Frequency value (Hz)
10.000000||tt| |10.000116
10.001157bZxz.net
10.003472
Daily difference (s/d)
—600
Frequency value (Hz)
10.000000| |tt||JJG488-—2008
Each standard daily difference is measured three times, and the arithmetic mean is taken as the measurement result. The measurement error is calculated according to formula (3).
6.3 Handling of Verification Result
A verification certificate shall be issued for a meter calibrator that passes the verification according to the requirements of this regulation; a verification result notice shall be issued for a meter calibrator that fails the verification and shall indicate the failed items. | |tt||6.4 Calibration cycle
The calibration cycle of a calibrator shall generally not exceed one year. Appendix A
1. Internal crystal oscillator
Power-on characteristics V=
Frequency accuracy A
2. Measurement error
1. Measuring electronic clocks| |tt||Standard daily deviation
Standard monthly deviation
2. Measuring mechanical clocks
Standard daily deviation
JJG488—2008
Calibrator Verification certificate (inside page) format
Measurement value
Measurement value
Appendix B
JJG488—2008
Selection of calibrator simulator|| tt||Since the calibrators are divided into electronic and mechanical types, and the electronic types are further divided into digital electronic and pointer electronic types, three different simulators need to be selected for calibration. To calibrate a digital electronic meter calibrator, you only need to place the signal output terminal of the frequency synthesizer on the sensor of the meter calibrator, and the meter calibrator will be able to identify the received daily error signal. The movement of a pointer electronic watch is used as a simulator, and the crystal oscillator inside the movement is replaced by the output frequency of a frequency synthesizer. The movement is placed on the sensor of a pointer electronic meter calibrator, and the meter calibrator can recognize and receive the daily difference signal.
To calibrate a mechanical calibrator, you need to use a piezoelectric ceramic or a reed relay as a simulator. The terminals of the frequency synthesizer are clamped onto the simulator to make the simulator emit a vibration signal. Put the simulator on the calibrator. The meter calibrator can identify and receive the daily difference signal on the meter's sensor.4533
Monthly difference (s/month)
Frequency value (Hz)
32768.0126
32768.0253
32768.0506
32768.0762||tt ||32768.1016
32768.1143
327 67.9873
32767.9746
32767.9492
32767.9238
32767.8984
32767.8857
Frequency value (Hz)
32768.0126||tt ||32768.0632
32 768.126 4
32768.3793
32768.6321
32769.2642
32767.9876
32767.9368
32767.8736
32767.6207
32767.3679
32766.7358
The measuring time of the calibrator is selected as 10s.
JJG488-2008
Each standard daily difference and standard monthly difference is measured three times, and the arithmetic mean is taken as the measurement result. The measurement error is calculated according to formula (3):
Formula In: E, the average daily difference (or monthly difference) measured; E. —— standard daily difference (or monthly difference); measurement error.
(2) Mechanical clocks||tt ||The beat of a mechanical clock is the number of vibrations of the hairspring per hour. The following are commonly used: 7200, 14400, 21600, 28800 and 36000, and the corresponding frequencies are 2Hz, 4Hz, 6Hz, 8Hz and 10Hz respectively. 10Hz is used as the nominal frequency value f3 for generating the standard daily difference. According to formula (4), the output frequency of the frequency synthesizer corresponding to the selected standard daily difference is calculated: Nf-fe
where: N is the standard daily difference value;
f3 is the frequency synthesizer output frequency corresponding to the selected standard daily difference. The frequency value of the synthesizer output during the daily difference is fo-10Hz.
The measurement range of the mechanical watch is generally (0 s/d～999s/d). The selection of the standard daily difference and the corresponding frequency are set according to Table 4. Certainly.
Table 4 Measurement range (0s/d~999s/d)
Daily difference (s/d)
Frequency value (Hz)
10.000000||tt| |10.000116
10.001157
10.003472
Daily difference (s/d)
—600
Frequency value (Hz)
10.000000| |tt||JJG488-—2008
Each standard daily difference is measured three times, and the arithmetic mean is taken as the measurement result. The measurement error is calculated according to formula (3).
6.3 Handling of Verification Result
A verification certificate shall be issued for a meter calibrator that passes the verification according to the requirements of this regulation; a verification result notice shall be issued for a meter calibrator that fails the verification and shall indicate the failed items. | |tt||6.4 Calibration cycle
The calibration cycle of a calibrator shall generally not exceed one year. Appendix A
1. Internal crystal oscillator
Power-on characteristics V=
Frequency accuracy A
2. Measurement error
1. Measuring electronic clocks| |tt||Standard daily deviation
Standard monthly deviation
2. Measuring mechanical clocks
Standard daily deviation
JJG488—2008
Calibrator Verification certificate (inside page) format
Measurement value
Measurement value
Appendix B
JJG488—2008
Selection of calibrator simulator|| tt||Since the calibrators are divided into electronic and mechanical types, and the electronic types are further divided into digital electronic and pointer electronic types, three different simulators need to be selected for calibration. To calibrate a digital electronic meter calibrator, you only need to place the signal output terminal of the frequency synthesizer on the sensor of the meter calibrator, and the meter calibrator will be able to identify the received daily error signal. The movement of a pointer electronic watch is used as a simulator, and the crystal oscillator inside the movement is replaced by the output frequency of a frequency synthesizer. The movement is placed on the sensor of a pointer electronic meter calibrator, and the meter calibrator can recognize and receive the daily difference signal.
To calibrate a mechanical calibrator, you need to use a piezoelectric ceramic or a reed relay as a simulator. The terminals of the frequency synthesizer are clamped onto the simulator to make the simulator emit a vibration signal. Put the simulator on the calibrator. The meter calibrator can identify and receive the daily difference signal on the meter's sensor.Measuring mechanical watches
Standard daily deviation
JJG488—2008
Calibrator calibration certificate (inside page) format
Measured value
Measured value
Appendix B
JJG488—2008
Selection of calibrator simulator
Since calibrators are divided into electronic and mechanical types, and electronic types are divided into digital electronic and pointer electronic types, three different simulators need to be selected for calibration. To calibrate a digital electronic calibrator, just put the signal output terminal of the frequency synthesizer on the sensor of the calibrator, and the calibrator can recognize and receive the daily deviation signal. To calibrate a pointer electronic calibrator, you need to use a pointer electronic watch movement as a simulator, and replace the crystal oscillator inside the movement with the output frequency of the frequency synthesizer. Put the movement on the sensor of the pointer electronic calibrator, and the calibrator can recognize and receive the daily deviation signal.
To calibrate a mechanical meter calibrator, you need to use a piezoelectric ceramic piece or a reed relay as a simulator. The terminals of the frequency synthesizer are clamped onto the simulator to make the simulator send out a vibration signal. Put the simulator onto the sensor of the meter calibrator, and the meter calibrator can then recognize and receive the daily difference signal.Measuring mechanical watches
Standard daily deviation
JJG488—2008
Calibrator calibration certificate (inside page) format
Measured value
Measured value
Appendix B
JJG488—2008
Selection of calibrator simulator
Since calibrators are divided into electronic and mechanical types, and electronic types are divided into digital electronic and pointer electronic types, three different simulators need to be selected for calibration. To calibrate a digital electronic calibrator, just put the signal output terminal of the frequency synthesizer on the sensor of the calibrator, and the calibrator can recognize and receive the daily deviation signal. To calibrate a pointer electronic calibrator, you need to use a pointer electronic watch movement as a simulator, and replace the crystal oscillator inside the movement with the output frequency of the frequency synthesizer. Put the movement on the sensor of the pointer electronic calibrator, and the calibrator can recognize and receive the daily deviation signal.
To calibrate a mechanical meter calibrator, you need to use a piezoelectric ceramic piece or a reed relay as a simulator. The terminals of the frequency synthesizer are clamped onto the simulator to make the simulator send out a vibration signal. Put the simulator onto the sensor of the meter calibrator, and the meter calibrator can then recognize and receive the daily difference signal.
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