JJG 953-2000 Verification Procedure for Precision Time Interval Meters JJG953-2000 Standard download decompression password: www.bzxz.net
This procedure is applicable to the initial verification and subsequent verification of precision time interval meters with a minimum interval of 1ns.

National Metrology Verification Standard of the People's Republic of China JJG953-—2000
Precision Time Interval Meter
Precision Fime lnterval Meter 2000 -- 07—09 Issued
Implementation on 2000—09—15
Issued by the State Administration of Quality and Technical Supervision
JJG 953—2000
Verification Regulation of Precision Time Interral Meter
IIG 953-—2000
This regulation was approved by the State Administration of Quality and Technical Supervision on July 9, 2000, and came into effect on September 15, 2000.
Responsible unit: National Technical Committee on Time and Frequency Metrology Main drafting unit: Communication Metrology Center of Ministry of Information Industry Participating drafting unit: National Institute of Metrology This regulation is interpreted by the National Technical Committee on Time and Frequency Metrology Main drafters:
Xiao Jia Drafters:
Wu Fengming
Chen Zhenheng
J.IG953—2000
(Communication Metrology Center of Ministry of Information Industry)
(China Institute of Metrology Institute)
【Communication Metrology Center of the Ministry of Information Industry
Model·
Meter performance requirements·
General technical requirements..
Metering instrument control
Verification conditions,
10 items and verification methods·
7.1 Appearance and working performance inspection
Verification of various indicators of internal qualityWww.bzxZ.net
JJG953-2000
.3 Time return isolation product uncertainty benefit 4 Verification of time interval measurement range
Processing of verification results
Verification cycle -
Appendix Verification certificate format
(1)
1 Scope
JJG953—20nD
Verification procedure for precision time interval measuring instruments
This procedure is applicable to the initial verification and follow-up verification of precision time interval measuring instruments with a minimum interval of 15 seconds. 2 Overview
When measuring precision time interval leakage, The measured part is divided into two parts: the part greater than one time base is measured using the principles of a digital time interval measuring instrument, i.e. the number of timing base pulses; the part less than one time base is measured using analog interpolation, digital cursor method or analog/digital (A/D) conversion method. Theoretically, the measurement resolution can reach 100%, but in reality, due to the influence of noise, the measurement is most unstable. Currently, only 100% precision time measurement can be achieved (hereinafter referred to as measurement). It is widely used in metrology, communication, high energy physics and other fields.
3 Metrological performance requirements
3.1 Internal crystal data
3.1.11 Aging rate: better than 1×10-8
3.1.2 Machine parts: better than 3×10-8
3.1.3 Frequency accuracy: better than 1×107
3.1.4 Frequency stability: better than 1×1010/183.2 Fashion measurement
3.2.1 Measured signal form:
Two positive pulses, two healing pulses, the time between a positive (negative) pulse and a negative (positive) pulse; the width of a single positive and negative pulse.
3.2.2 Measured signal level: TTL
3.2.3 Measurement range: 1nx-10s
3.2.4 Accurate uncertainty
The standard uncertainty of the measurement consists of the following parts: 1: Standard uncertainty caused by resolution and system noise, 15~100S; 3: Standard uncertainty caused by the half-wavelength error, 50mV/signal update rate; 4: Standard uncertainty caused by input channel error, the above items are combined to form the inherent standard uncertainty: =Vur+u+ u
ul: Standard uncertainty caused by time base inaccuracy. The standard uncertainty caused by time base inaccuracy can be found in the measurement specification. (1)
4 General technical requirements
JJG953—2000
The front or back of the measuring instrument shall be covered with the following marks: manufacturer, instrument model, factory serial number and certification mark. The measuring instrument shall have a crystal oscillator or a simple output port for measuring the control device, keypad and input port. The measuring instrument shall be accompanied by the instruction manual and the previous inspection certificate during operation. 5 Instrument control
Includes the initial inspection and subsequent inspection. The initial inspection is for a new measuring instrument that has not been inspected before. The subsequent inspection is a kind of inspection after the initial inspection. It includes the inspection within the validity period, periodic inspection and follow-up inspection. During the final calibration, the main unit shall have the calibration mark of Model F:
The first calibration and subsequent calibrations shall be carried out in accordance with this regulation. 6 Calibration conditions
6.1 Environmental conditions
6.1.1 Ambient temperature: It can be selected within the range of 15-30℃. The humidity change during calibration should not exceed 12℃: 6.1.2 Relative humidity; not less than 10%.
6.1.3 Power supply voltage: (220=10)V
6.1.4 Commercially available electromagnetic interference and mechanical vibration that do not affect the working condition of the measuring instrument 6.2 Calibration equipment
6.2.1 Test frequency standard
The frequency aging rate, start-up performance and discharge rate accuracy shall be one order of magnitude higher than the corresponding standards of the crystal oscillator inside the micro-detection instrument, and the frequency stability shall be 3 times higher.
6.2.2 Digital standard comparator
Measurement uncertainty is less than 1×10! 6.2.3 Standard time interval generator
6.2.3.1 Signal form:
Two outputs positive and negative pulse train:
Two outputs single pulse;
Single output positive and negative pulse width,
6.2.3.2 Signal level: 11L.
6.2.3.3 Delay: 1 ns--10 s
5.2.3.4 Standard uncertainty: 1ns
6.2.3.5 The time between pulses and the following is less than 16.2.1 Special delay line (50): 1,,3,JU.
Standard time: 100S
7 Verification items and verification methods
7.1 Appearance and working performance inspection
JIG 953—200
7.1.! The instrument to be tested should not have mechanical damage that affects normal operation. The function switches and buttons should be flexible and reliable, and should comply with the provisions of the general technical requirements.
7.1.2 Turn on the power supply, and the standard time generator should give a time interval signal at any time within the measuring range of the instrument to be tested, and check whether the various functions of the measuring instrument are stopped. Various indicator lights and measurement displays should be clearly visible. After these two inspections are confirmed to be intact, the following verifications can be carried out. 7.2 Verification of the necessary crystal oscillator indicators
The various indicators of the internal oscillator shall be carried out in accordance with JJC180-1978 "Trial Verification Procedure for Crystal Oscillators in Electronic Counters" and JJC181-1989 "Verification Procedure for High Stability Crystal Oscillators". The crystal frequency aging rate is only verified when the instrument is first verified.
7.3 Verification of the uncertainty of time interval measurement 7.3.1 Method 1: Use standard delay line
7.3.1.1 Instrument connection as shown in Figure 1, A, B two lines are precision coaxial fixed delay lines. A
Standard time interval
Drum control measuring instrument
Determination of the uncertainty of the time interval to be measured, 3, 1.2 The standard time interval generator (hereinafter referred to as the generator) outputs positive pulses in parallel, with a repetition period of 1ums: the calibration point is:
T= ry- ra-] nx
Formula: EB, A——B, delay time of two lines A: 7.3.1.3 The "Number of measurements" is selected as 100. In the measurement results, read the half-mean value and standard deviation g and calculate u according to the following formula:
In the formula; is a one-to-one error.
7.3.2 Method: Use standard time leakage generator 7.3.2.1 Instrument connection as shown in Figure 2. A and H are two cables of the same length: (2)
7.3.2.2 The generator gives two positive continuous pulse trains, the level is 1TL level, the pulse repetition period is 10m9, and the interval between the two pulses is 1n, which are respectively added to the start and stop input terminals of the instrument to be tested, 3
J.IG9532000
3.2.3 The instrument to be tested is about +", and the trigger voltage is selected as 2.0V. Press 7.3.1.3 force method for measurement and calculation,
standard time interval
generator
detected instrument
Figure 2 time interval between the intensity of the two fast determination
7.4 time interval between two points of the calibration
4.1 two positive pulses
7.4.1.1 instrument should be connected as shown in Figure 2. 4.B are two cables of the same length. 7.4.1.2 the trigger slope of the two inputs of the instrument are both selected as "positive", the trigger level is selected as 2.0V, 4,1.3 the generator outputs two positive pulses, the interval of the output is called the standard value, which is selected as 10ns101, 10, 100, 1m, 10m, 100m91 and 10. Each value, 10 times to take the arithmetic mean as the measurement error, minus the standard value, is the measurement error of each calibration point. 7.4.2 Interval between two negative pulses
7.4.2.1 The instrument connection is shown in Figure 2. The trigger slope of both inputs of the tester is selected as "negative", the trigger level is still set to 2.0, and other operations are the same as 7.4.1.3.
7.4.3 Stop pulse width
7.4.3.1 With connection Figure 3:
Generator energy
Bear
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? .4.4.1 The connection of the transmitter is shown in Figure 3
7.4.4. The transmitter inputs a small single pulse width signal. The input mode of the instrument is selected as "normal", the slope of the start end is selected as "negative", and the stop end is selected as "positive". The range of the power generation is within 2V. 4.4.3 Selection of inspection points and inspection methods 7.1.1.3..4
8 Processing of inspection results and inspection cycle
JIC 953-200-0
.1 For the instrument that passes the inspection, a certificate of inspection shall be issued: for the instrument that passes the inspection, a notice of inspection results shall be issued, and the unqualified items shall be noted.
8.2 The inspection cycle of precision time interval measuring instruments shall generally not exceed 1 year. Appendix
1. Verification of internal crystal oscillator
1. Frequency aging rate:
2. Frequency stability (stable in seconds):
3. Power-on characteristics;
4. Frequency accuracy.
1. Uncertainty of measurement
3. Determination of pulse-to-pulse measurement range
Standard value
Standard value
JJG953—2000
Verification certificate internal format
Measurement error (ns)
Two pulses
Measurement error (L)
Positive pulse
Two pulses
Negative pulse width
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