GB 5170.14-1985 Basic parameter verification methods for environmental test equipment for electrical and electronic products - Electric vibration table for vibration (sinusoidal) test
Some standard content:
National Standard of the People's Republic of China
Environmental testing equipment for electric and electronic products,
Basic parameters verification methods
Electrodynamic vibration table for vibration (sinusoidal) testUDC 621.3
.002.f-79
GB 5170.14—85
This standard specifies the verification methods for basic parameters of the electric vibration table system (hereinafter referred to as the vibration table) for vibration test according to GB2423.10 "Basic environmental test procedures for electric and electronic products Test Fc: Moving (sinusoidal) test method". The vibration table consists of a vibration table body, an excitation power supply, a power amplifier, a control and measurement device, and a horizontal workbench (when the test system requires it).
1 Determined items
1.1 Rated parameters
1.1.1 Thrust
1.1.2 Frequency range
County. No-load frequency range,
Full-load frequency range.
1.1.3 Load
Maximum load;
Load eccentric moment:
Horizontal load moment:
Maximum anti-bumping moment (when equipped with a horizontal workbench) 1. 1.4
Vibration amplitude
No-load maximum acceleration amplitude:
Full-load maximum acceleration amplitude;
Maximum velocity amplitude,
Maximum displacement amplitude.
Acceleration waveform distortion
Lateral vibration
1.4 Table acceleration amplitude uniformity
1.5 Frequency indication error
1.6 Frequency stability
1.7 Amplitude indication error
1.8 Background noise acceleration
Published by the National Bureau of Standards on April 7, 1985
Implemented on January 1, 1986
1.9 Fixed vibration accuracy
1.10 Maximum sound level of radiated noise
1.11 Table leakage magnetic flux
1.12 Table temperature
1.13 Continuous operation time
1.14 Sweep rate error
2 Main instruments for calibration
Accelerometer:
GB 5170.14—85
Three-axis accelerometer:
Sine vibration measuring instrument (hereinafter referred to as vibration measuring instrument, which should include multi-channel amplifier, frequency selector, operator and display); frequency meter,
distortion measuring instrument,
level recorder:
Low-frequency oscilloscope:
Sound level meter,
Gaussmeter,
Surface thermometer.
3 General provisions
Calibration load
Calibration load should be made of metal material with symmetrical rigid body, its mass, center of mass height and installation eccentricity should comply with relevant regulations and meet the following requirements;
Fixing bolts should be used in all available installation positions, a.
The length between the fixing screw head and the threaded constraint part should make its installation resonance frequency outside the test frequency range: b.
e. The contact surface flatness tolerance is 0.1/1000, and the finish is level 7; d. Thin loads should be avoided, the ratio of thickness to diameter (or diagonal dimension) should be greater than 0.4, and its maximum diameter (or diagonal dimension) should not be greater than the diameter of the vibration table. 3.2 Accelerometer
1. The installation resonance frequency of the accelerometer should be greater than 5 times the first-order resonance frequency of the moving parts of the vibration table, b. Accelerometers with small mass should be selected as much as possible. 3. For vibration tables with horizontal worktables, except for the frequency indication error, frequency stability, sweep rate error, amplitude indication error, and table temperature, all other items shall be verified in accordance with the corresponding clauses in the verification method. 4 Verification method
4.1 Verification method for rated parameters of vibration table
Rated parameters of vibration table include:
a. Thrust,
Thrust corresponds to a specific test load mt, which is calculated by the following formula: Fm=(m.+m,)a
（１）
Thrust, N,
Wu Fm
-Equivalent mass of the moving parts of the vibration table: (see product manual or refer to the recommended method in Appendix A for determination), kgm
Mass of the test load, kg;
Vibration acceleration amplitude, 9.
b. Frequency range:
e: Vibration amplitude.
4.1.1 Test conditions
GB5170.14—85
The vibration table is unloaded and fully loaded. The center of the table (or load surface) is rigidly connected to the accelerometer, and its output is connected to the frequency meter through the vibration meter (see Figure 1).
Velocity meter
4.1.2 Test method
Velocity meter
The vibration table is unloaded and fully loaded. Select 10 frequencies in the unloaded and fully loaded frequency ranges, adjust the amplitude to the maximum, and the measured vibration amplitudes should all meet the specified maximum vibration amplitudes. .2 Verification method for acceleration waveform distortion 4.2.1 Test conditions
The vibration table is unloaded, the center of the table is rigidly connected to the accelerometer, and its output is connected to the distortion meter and oscilloscope through the vibration meter (see Figure 2). Accelerometer
4.2.2 Test method
Lake condenser
Lake comparison
Wavelet generator
Twist, evenly select 10 frequencies within the specified no-load frequency range, the vibration amplitude is the maximum amplitude (maximum displacement amplitude or maximum velocity amplitude or no-load maximum acceleration amplitude) of the corresponding frequency, and measure the acceleration waveform distortion. b. Within the specified no-load frequency range, use the swept frequency vibration method to repeatedly find the frequency with poor acceleration waveform, and measure its acceleration waveform distortion. If there is a frequency with distortion exceeding the specified error, the bandwidth exceeding the distortion error should be measured at the same time. 4.3 Verification method for transverse vibration
4.3.1 Test conditions
The moving table is unloaded, and the center of the table is rigidly connected to the three-axis accelerometer, and its input is connected to each input channel of the vibration meter. The output of the measuring instrument (referring to the corresponding channel for detecting lateral movement) is connected to the recorder (see Figure 3). 4.3.2 Test method GB 5170.14--85 9. Use the swept frequency vibration method to find the frequency where the lateral vibration is larger. Within the specified frequency range, the main lever direction is subjected to constant amplitude swept frequency vibration, and the frequency where the lateral movement is larger is determined by the lateral vibration frequency response characteristics H) and H\) measured by the recorder. b. Select any 10 frequencies (including the frequencies determined in 4.3.2 a) within the specified no-load frequency range, and the acceleration amplitude in the vibration direction on the table is the maximum amplitude specified at the corresponding frequency, and the acceleration amplitudes in the two directions are measured. 4.3.3 The lateral vibration ratio is calculated as follows:
Va+a,?
Where: a, - - acceleration amplitude in the main alarm direction in the same measurement, g×100%
lateral acceleration amplitude perpendicular to the main alarm direction and perpendicular to each other in the same measurement, 9. d+→@y
Note: For the horizontal vibration of the alarm table with a water half workbench, the lateral vibration measurement of the installation point farthest from the center of the table surface must also be carried out simultaneously. 4.4 Verification method of table surface acceleration amplitude uniformity 4.4.1 Test conditions
The moving table is unloaded. Select an installation point at the center of the table surface and each mounting bolt circle (necessary engineering judgment is required to make the absolute value of the deviation of the acceleration amplitude of this point relative to the acceleration amplitude of the center point of the table surface the largest), rigidly connect the accelerometer, and the output of each accelerometer is connected to each input channel of the vibration meter (see Figure 1). Accelerometer.
Moving table
4.4.2 Test method
Select 10 frequencies within the specified no-load frequency range, and the acceleration amplitude at the center of the table is the maximum amplitude specified at the corresponding frequency, and measure the acceleration amplitude at each point respectively. 4.4.3 The uniformity of the acceleration amplitude of each surface is calculated as follows: N-
lAamarl
-The acceleration amplitude at the center of the table in the same measurement, 9100%
The absolute value of the maximum deviation of the state velocity amplitude of each point on the table relative to the acceleration amplitude of the center point in the same measurement, 9.
4.5 Verification method of frequency indication error
4.5.1 Test conditions
The output of the vibration table signal generator is connected to the frequency meter (see Figure 6). 4.5.2 Test method
Signal generator of the vibration table
GB 5170-14—85
Report frequency indication
Rated frequency meter
Within the specified no-load frequency range, select 10 frequencies for measurement, record the vibration table frequency indication and the frequency meter indication, and calculate their errors.
4.6 Verification method of frequency stability
4.6.1 Test conditions (same as 4.5.1)
4.6.2 Test method
At the highest and lowest frequencies (or any two frequencies) within the specified no-load frequency range, work continuously for 4 hours each, and record the frequency indication once every 15 minutes.
4.6.3 The frequency stability is calculated as follows:
×100% or Afmax
where -
given test frequency indication, Hz
-the maximum deviation of the frequency indication from the given frequency value in each measurement, Hz. 4.7 Verification method of amplitude indication error
4.7.1 Test conditions
The vibration table is unloaded. The accelerometer is rigidly connected to the center of the table surface, and its output is connected to the vibration meter (see Figure 6). The vibration meter
accelerometer
reports the amplitude indication of the vibration table
most dynamic
4.7.2 Test method
Within the specified unloaded frequency range, evenly select no less than 3 frequencies, select 5 amplitude values at each frequency point and measure them in turn, and record the amplitude indication of the vibration table and the indication of the vibration meter. 4.7.3 The amplitude indication error is calculated as follows: at -aw
Where: ao
×100%
In the same measurement, the amplitude indication value of the vibration meter, mm In the same measurement, the amplitude indication value of the moving table, mm. 4.8 Verification method of background noise acceleration
4.8.1 Test conditions (same as 4.7.1)
4.8.2 Test method
GB5170.14—85
Connect the power supply of the vibration table, the excitation and cooling devices and the power amplifier are all in the T working state, the output signal of the control device is zero, and the effective value of the table surface noise acceleration is measured.
4.9 Verification method of fixed vibration accuracy
4.9.1 Test conditions
The vibration table is unloaded and fully loaded. The center of the table (or the top surface of the load) is rigidly connected to the accelerometer, and its output is connected to the level recorder through the vibration meter (see Figure 7).
Accelerometer
Vibration table
4.9.2 Test method
Camera
Level recorder
No-load and full-load vibration table. Within the specified frequency range, the sweep frequency rate is 1 octave/min, and the maximum acceleration and minimum acceleration values allowed by the vibration table are respectively used to position and shift a certain acceleration reciprocating sweep frequency vibration. The maximum unevenness of the fixed vibration frequency characteristic measured by the level recorder is the fixed vibration accuracy. bZxz.net
.10 Method for determining the maximum sound level of radiated dish sound The vibration table is no-load. Within the specified frequency range, the vibration table is swept frequency with the maximum amplitude allowed by the vibration table. The maximum sound level value is measured and recorded with a sound level meter (A-weighted network) at a height of 1m away from the edge of the vibration table. 4.11 Verification method of magnetic leakage
The excitation device of the vibration table is in the working state, and the magnetic flux density of the plane parallel to the lower table surface and the space above the surface is measured with a gauss meter, which is 1/4H away from the table surface and the maximum bolt point diameter (or diagonal dimension). All positions where the screw sleeves are installed should be used as measurement points, and the maximum value of the magnetic field intensity at each point is measured. 4.12 Verification method of table surface temperature
The vibration table surface is unloaded. At the electromechanical resonance frequency, the maximum acceleration amplitude of the unloaded state is used for fixed frequency vibration, and it is continuously operated according to the specified continuous working time, and the maximum value of the table surface temperature is measured. 4.13 Verification method of continuous working time
4.13.1 No-load test
The vibration table is unloaded. The accelerometer is rigidly connected to the center of the table surface, and its output is connected to the recorder through the vibration meter. Within the specified no-load frequency range, the vibration table shall be vibrated reciprocatingly with a certain acceleration at a sweep rate of 1 octave/min and the specified no-load maximum acceleration value and the corresponding displacement amplitude. The table shall operate normally and the vibration accuracy shall meet the specified requirements.
4.13,2 Load test
The vibration table is fully loaded. The vibration table shall be vibrated at a fixed frequency at the upper frequency limit of the specified maximum displacement amplitude and the maximum displacement value. The table shall operate normally in the vertical and horizontal directions according to the specified continuous working time. 1. 4.14 Verification method of sweep rate error
(to be determined)
GB5170.14-85
Appendix A
Method for measuring equivalent mass of moving parts
(reference)
The equivalent mass m of the moving parts can be measured by the following method A.1 Determine the resonance frequency of the unloaded suspension of the vibration table 1. The vibration table is subjected to constant speed sweep frequency vibration (the frequency range is generally between 1 and 100 Hz), and the frequency at which the moving coil current is the minimum is sn
A,2 Determine the first-order resonance frequency m of the vibration table under the specified load. The vibration table is subjected to constant voltage sweep vibration under the specified load. The frequency at the maximum acceleration amplitude is t. A.3 The vibration table is unloaded. The frequency is f (/ should be 3f. ~1/3/, selected between), and the corresponding moving coil reference current is 1. The unloaded table acceleration q is measured.
A.4 The vibration table is fully loaded. The load mass m is known, corresponding to the same frequency / and current I in A.3, the full-load acceleration d2 is measured. A .5 The equivalent mass is calculated as follows:
GB5170.14—85
Appendix B
Selection of verification items
(reference)
When the vibration table is subjected to type identification, factory inspection and regular verification, if there are no other provisions in the relevant standards, the verification item number can be selected according to the following table
Verification table name
Rated parameters of vibration table
a. Destructive force
b. No-load frequency range|| tt||Full load frequency range
Maximum acceleration amplitude at no load
Maximum acceleration amplitude at full load
f, maximum velocity amplitude
g, maximum displacement amplitude
Acceleration waveform sharpness
Lateral vibration
Uniformity of acceleration amplitude on table
Frequency indication error
Frequency stability
Movement indication error
Vibration fixing accuracy
Background noise Speed
Table surface magnetic field
Maximum sound level of radiated noise
Table surface turbulence
Continuous working time
Frequency error
Type verification
Factory inspection
Periodic verification
Test clause
Note: The symbol "" indicates the items that must be verified, and the symbol "△" indicates the items that are sampled or selected for verification (either the verification party or the verified party proposes the items that need to be verified).
GB 5170.14—B5
Appendix C
Basic parameter error requirements
(reference)
When the vibration table is regularly verified, the basic parameter error requirements can refer to the following table. No.
Test Item
Acceleration waveform distortion
Horizontal vibration
Table acceleration
Amplitude uniformity
Frequency indication error
Frequency stability
Amplitude indication error
Vibration fixation accuracy
Sweep rate error
Additional remarks:
Error requirements
For frequencies below 20Hz and above 2000Hz, no more than 25%For frequencies from 20Hz to 2000Hz, no more than 15%For frequencies below or equal to 500Hz, no more than 25%For frequencies above 500Hz, no more than 50%
For frequencies below or equal to 500Hz, not more than 15%Frequency over 500Hz, not more than 25%
< 5Hz, ±2n%
5Hz to 50Hz, +1Hz
> 50Hz, ±2%
< 5Hz, every 4h=20%
5Hz to 50Hz, every 4h±1Hz
> 50Hz, every 4h±2%
If the error requirement is not met, the value shall be recorded
If the error requirement is not met, the value shall be recorded
This standard is proposed by the National Technical Committee for Environmental Conditions and Environmental Testing of Electrical and Electronic Products. This standard is drafted by the Working Group on Verification Methods of Basic Parameters of Environmental Testing Equipment. The main drafter of this standard is Pan Xinghong of the 79th Factory of the Electronic Industry Department.14—B5
Appendix C
Basic parameter error requirements
(reference)
When the vibration table is regularly calibrated, the basic parameter error requirements can be referred to the table below. No.
Test Item
Acceleration waveform distortion
Horizontal vibration
Table acceleration
Amplitude uniformity
Frequency indication error
Frequency stability
Amplitude indication error
Vibration fixation accuracy
Sweep rate error
Additional remarks:
Error requirements
For frequencies below 20Hz and above 2000Hz, no more than 25%For frequencies from 20Hz to 2000Hz, no more than 15%For frequencies below or equal to 500Hz, no more than 25%For frequencies above 500Hz, no more than 50%
For frequencies below or equal to 500Hz, not more than 15%Frequency over 500Hz, not more than 25%
< 5Hz, ±2n%
5Hz to 50Hz, +1Hz
> 50Hz, ±2%
< 5Hz, every 4h=20%
5Hz to 50Hz, every 4h±1Hz
> 50Hz, every 4h±2%
If the error requirement is not met, the value shall be recorded
If the error requirement is not met, the value shall be recorded
This standard is proposed by the National Technical Committee for Environmental Conditions and Environmental Testing of Electrical and Electronic Products. This standard is drafted by the Working Group on Verification Methods of Basic Parameters of Environmental Testing Equipment. The main drafter of this standard is Pan Xinghong of the 79th Factory of the Electronic Industry Department.
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