Some standard content:
Military Standard of Electronic Industry of the People's Republic of China FI.0150
Verification regulation of
LF digltal phase meter
1993—02—09 Issued
China Electronics Industry Corporation
SJ20245--93
Implementation on 1993-05—01
Military Standard of Electronic Industry of the People's Republic of China Verification regulation of
LF digital phase meter
1 Scope
1. 1 Subject Content
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This verification regulation specifies the verification conditions, verification items, verification methods, verification result processing and verification cycle of low frequency phase meters. 1.2 Scope of application
This verification procedure applies to the verification of low-frequency phase meters. 2 Referenced documents
No clauses in this chapter.
3 Definitions
No clauses in this chapter.
4 General requirements
4.1 Purpose and principle of the inspected measuring instruments
China Electronics Industry Corporation
Published on February 9, 1993, implemented on May 1, 1993 I
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Modern low-frequency phase meters mostly adopt the principle of zero-crossing detection and pulse phase detection and automatic error correction technology.
Low-frequency phase meters are generally composed of dual-channel zero-crossing detectors, pulse phase detectors, phase quantization and displays.
Low-frequency phase meters are mainly used to measure the phase characteristics (α) of the most linear network. It can also be used to measure the resonant frequency f of the loop. Low frequency phase meter is also used to measure the quality factor Q and consumption D of the loop. Low frequency phase meter is applied to crystal characteristics, network delay characteristics, power system, metal detection, metal thickness measurement, ranging and orientation. 4.2 Technical requirements
4.2.1 Frequency range
1kHz1MHz.
4.2.2 Phase measurement range
0~360°,180/-180°
4.2.3 Phase resolution
4.2.4 Phase measurement error
±0. 1.
4.2.5 Frequency response error
It is specified in the manual of each instrument.
4.2.6 Amplitude and phase error
It is specified in the manual of each instrument.
4.3 Verification conditions
4.3.1 Environmental conditions
a. Ambient temperature, 20±2℃;
b. Relative humidity: 45%~75%;
e. Atmospheric pressure: 86~106kPa;
d. Power supply: 220V±2%, 50±0.5Hz; e. Surrounding environment: There should be no strong electromagnetic interference. 2
4.3.2 Calibration equipment
4.3.2.1 Frequency synthesizer
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Frequency range: 200Hz~80MHz;
Frequency resolution: 0.001Hz:
Rated frequency accuracy: ±1×101
Amplitude range: -86~+13dBm;
Absolute level accuracy: ±0.1dB:
Reference model: HP3335A. www.bzxz.net
4.3.2.2 Standard delay line
8. Microsecond standard delay line
Frequency range: 30kHz~15MHz;
Delay time: 5us;
Impedance: 50m:
Delay dispersion: (when pulling) 1×10-5;
Reference model: 5120B
b. Millisecond standard delay line
Frequency range: 1030kHz;
Delay time: 0.3~5ms (variable),
Impedance: 502/6002:
Delay dispersion: (when narrowband) 1×10,
Reference model: 5120C.
4.3.2.3UHF potentiometer
Rated power: 1W;
Characteristic impedance: 502:
Attenuation: 0~50dH:
Reference model: WHP-2.
4.3.2.4Coaxial attenuator
Frequency range: DC～12GHz;
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Attenuation: 10dB, 15dBg
Impedance: 502:
Reference model: TS23M1.
4.3.2.5T-type connector
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Reference model: Q9—50KIK.
5 Detailed requirements
5.1 Verification items and verification methods
5.1.1 Appearance and normal working inspection
5.1.1.1 The low-value phase meter under inspection (hereinafter referred to as the inspected instrument) shall be accompanied by the product technical manual and necessary accessories. If it is not the first verification, the previous verification certificate shall be attached. 5.1.1.2 The inspected instrument shall have no mechanical damage that affects its positive belt operation and correct reading: the rotation shall be smooth.
5.1.1.3 According to the requirements of the instrument manual, the instrument shall be able to work normally after power-on inspection. 5.1.2 Phase accuracy verification
5.1.2.1 Connect the measuring instrument according to Figure 1.
Frequency synthesizer
Standard delay line
PT connector 15dE
Attenuator
D connector
Hundred 5on
Tested instrument
5.1.2.2 Measurement of the total phase delay difference tr between the "reference" channel and the "signal" channel in Figure 1
Adjust the output signal frequency of the frequency synthesizer to f (f. is the calibration frequency of the tested instrument), and read the phase value at f on the tested instrument. After recording the value, unilaterally change the signal frequency of the frequency synthesizer to change the phase reading until the phase changes to (-+360°), and record the signal frequency f2 at this time. According to f, and f2, calculate the phase delay difference tp according to formula (1).
5.1.2.3 Principles for determining the Tr value
The value should make Aff, i.e.,
±0. 1～~0. 01
If equation (2) is not satisfied, then increase the tp value, i.e., increase the delay value of the standard delay line, so that △f decreases and satisfies the requirements of equation (2). Note: If the resolution or stability of the detector under test is not high, a phase meter with better performance can be used for measurement.
5.1.2.4 Establishing the standard phase
The standard phase value is calculated according to equation (3) based on the value obtained from equation (1). =otp=360/tp
Where: 0-2 element f
and take a series of specific values, that is:
4=nX30°
n- 1.,2,3,4-.*-
++*++(3)
For different values, corresponding to the signal frequency f., the value is calculated according to formula (3). The f. value and the standard phase value are recorded in Table A1 of Appendix A (Supplement). 5.1. 2. 5 Verification of phase measurement error
Connect the measuring instrument according to Figure 1. According to the frequency points given in Table A1, adjust the signal frequency of the frequency synthesizer. Read the corresponding phase value f) on the instrument under test, and record the f) value in Table A1. According to the data in Table A1 and (f), calculate the phase measurement error g of the instrument under test according to formula (5), and record the result in Table A1. g(f)-
Where: Standard phase value:
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() The actual measured value of the instrument under test.
5.1.3 Frequency response error verification
5.1.3.1 Connect the measuring instrument according to Figure 1. The verification method is basically the same as Article 5.1.2.5, except that the standard phase value can only select an arbitrary value that is not close to the phase ambiguity point, such as 90°.
5.1.3.2 According to the frequency response error and test frequency points specified by the instrument under test, measure the phase accuracy one by one (for the same standard phase value, such as ≤ 90), refer to Article 5.1.2.5, and find the values at different rates. Record in Table A2. 5.1.3.3 The phase ambiguity point is also called phase discontinuity. When the phase meter works in the range of 0~360, the phase ambiguity point is at 0°+9 and 360°, where 9 is the phase ambiguity area of the phase meter. When the phase meter works in the range of 180/-180°, the phase ambiguity point is at 180°±4. When the phase meter frequency response error is tested, the value should be 20° or more away from the phase ambiguity point.
5.1.4 Amplitude-phase error test
The amplitude-phase error of the phase meter is divided into two categories, namely: the first type of amplitude-phase error and the second type of amplitude-phase error.
The first type of amplitude-phase error: When the amplitudes of the two input signals of the phase meter are synchronously and in the same direction, the error generated by the phase meter is expressed as (1); the second type of amplitude-phase error: When the amplitude of one input signal of the phase meter is fixed and the amplitude of the other input signal changes, the phase measurement error generated is expressed as (I). 5.1.4.1 First-type amplitude and phase error verification
Connect the measuring instrument according to Figure 1, the signal frequency is fixed, and the phase value is also fixed. Use the instrument under test to read the phase value. The amplitude of the output signal of the frequency synthesizer changes within the dynamic range specified by the instrument under test. Record the phase readings $(A) of different signal levels respectively and record them in Table A3. Calculate the first-type amplitude and phase error △g (I) according to formula (6) and record it in Table A3.
Ap([)=p(A)mx-(A)mn*+**** (6) In the formula: (A)——the maximum value of -(A): 6
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(A)min——the minimum value of (A).
5.1.4.2 Second-type amplitude and phase error verification
a. Connect the measuring instrument according to Figure 2. After the frequency synthesizer output signal frequency is adjusted to a certain frequency within the frequency band of the instrument under test, it remains fixed. The ultra-high frequency potentiometer
synthesizer
T connector
100o
test instrument
Dingpo head
h. Make the input signal amplitude of the reference branch of the instrument under test fixed (select the minimum, maximum, and middle voltages of the instrument's dynamic range respectively). Change the input signal amplitude of the "signal" branch of the instrument under test from the minimum value of its dynamic range to the maximum value, and observe the maximum value of the phase indication change of the instrument under test (). A (1) is the second type of amplitude-phase error. When the "reference" branch signal amplitude takes the minimum, maximum, and middle values respectively, the (I) values obtained may be different. Divide them into c. Interchange the coaxial attenuator and the ultra-high frequency potentiometer in Figure 2, repeat the above-mentioned second-type amplitude-phase error calibration operation, and record the results in Table A4. Take the maximum value of Ag, (1) in Table A4 as the second-type amplitude-phase error of the instrument. 5.2 Calibration result processing and calibration cycle
5.2.1 For instruments that pass the calibration, a calibration certificate shall be issued; for those that fail the calibration, a calibration result notice shall be issued, and the unqualified items shall be indicated. 5.2.2 The calibration cycle is one year. It can be sent for inspection at any time when necessary. 7
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Appendix A
Calibration record table format
(supplement)
Table A1 Phase accuracy verification
Test the signal continuity rate.
Standard phase table
Phase test body↑)
Phase measurement error
Signal rate!
Phase accuracy
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9120150 180210240270300 330360 Table A2 Verification of phase error
Table A3 Verification of first type amplitude and phase error
Input signal amplitude
Phase meter indication A)
Table A4 Verification of second type amplitude and phase error
\Reference" Branch input signal phase
Minimum level
Intermediate level
Value\ Branch withdrawal signal amplitude
Maximum level [Minimum level Intermediate level Maximum level Additional instructions,
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This standard is proposed by the Science and Technology Quality Bureau of China Electronics Industry Corporation. This standard is under the jurisdiction of China Electronics Technology Standardization Institute. This standard was drafted by the Electronic 402 Metrology Station of the Ministry of Machinery and Electronics. The main drafter of this standard: Li Deru.
Project code: 075-1~47.
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