Some standard content:
Mechanical Industry Standard of the People's Republic of China
High Voltage Oscilloscope for Impact Test
JB/T7089-93
The high voltage oscilloscope is a pulse oscilloscope specially designed for high voltage and high current impact test. It is used to measure and record the transient process of a single impact wave. It has the characteristics of high recording speed, strong anti-interference and impact resistance. There is no amplifier installed between the measurement signal input end and the deflection plate of the high voltage oscilloscope, only a passive attenuator, and a single scan function with external synchronous triggering.
High voltage oscilloscopes usually use high voltage oscilloscope tubes with good shielding and low deflection sensitivity. The oscilloscope should be equipped with a voltage scale signal (amplitude scale) for verifying the vertical deflection sensitivity and a time scale signal (time scale) for verifying the scanning speed. The measurement accuracy of the high voltage oscilloscope must meet the requirements of GB311.4-83.
1 Subject content and scope of application
This standard defines the terms related to high-voltage oscilloscopes; specifies the measurement accuracy that the oscilloscope must achieve, and proposes the technical conditions that must be met to achieve the specified accuracy; specifies the performance test items and test methods that must be carried out to meet these technical conditions. This standard applies to high-voltage oscilloscopes that measure impulse voltage and impulse current waves. 2 Reference standards
GB4793
GB6593
3 Terms
3.1 Transmission characteristics
High voltage test technology
Safety requirements for oscilloscopes and peak voltmeters for impulse tests
Inspection procedures for electronic measuring instruments
Quality inspection rules for electronic measuring instruments
Transmission characteristics refer to the relationship between the output and input of a high-voltage oscilloscope, which is usually expressed as a function of frequency or time. The transmission characteristics can be obtained through experiments, and are usually expressed in the form of rate response or square wave response with the constant part as the unit value. Time.
The square wave response of the oscilloscope is expressed by the square wave rise time t, where t is the time it takes for the square wave front edge to rise from 10% to 90% of the steady-state value. The frequency response characteristics of the oscilloscope are expressed by bandwidth or upper and lower cut-off frequencies. The upper and lower cut-off rates are defined as the frequency band where the constant part of the amplitude response curve of the sine wave input signal drops by 3dB (0.707), and the bandwidth is the difference between the upper and lower frequencies f2 and f,. The transmission characteristics of the high-voltage oscilloscope include the influence of the internal attenuator. 3.2 Attenuation ratio
The measured signal input is attenuated by the internal attenuator of the oscilloscope and output to the vertical deflection plate of the oscilloscope tube. The ratio of the input signal amplitude to the auxiliary output signal amplitude is called the attenuation ratio. Proper adjustment of the attenuation ratio can place the measured signal waveform in the effective screen area specified in 3.11. 3.3 Attenuation ratio nominal value
At a certain attenuation gear, the attenuation ratio value given by the manufacturer after verification is called the nominal value at that gear. Approved by the Ministry of Machinery Industry on October 8, 1993
Implemented on January 1, 1994
3.4 Amplitude calibration voltage
JB/T7089-93
The internal DC reference voltage used for routine calibration to determine the amplitude of the waveform being measured is called the amplitude calibration voltage (amplitude standard). 3.5 Nominal value of amplitude calibration voltage
At a certain gear, the voltage value given by the manufacturer after calibration for routine calibration to determine the vertical deflection sensitivity is called the nominal value of the amplitude calibration voltage.
3.6 Time scale
The reference value used for routine calibration to determine the horizontal scanning time, that is, the time represented by this reference value for each deflection of the light track in the horizontal direction is called the time scale, and the time scale unit is ns, us, ms. 3.7 Nominal value of time scale
At a certain gear, the time scale value given by the manufacturer after calibration is called the nominal value of the time scale. 3.8 Linearity
Under the same gear, the maximum deviation of the actual deflection value of each point on the screen from the nominal value of the gear is called nonlinearity. Nonlinearity can be characterized by the ratio of this deviation to the nominal value. This ratio is called nonlinearity. Nonlinearity includes vertical deflection nonlinearity and horizontal deflection nonlinearity. 3.9 Measuring screen area
The measuring screen area is a part of the entire screen. The specified accuracy can be obtained in this part. This accuracy and the measuring screen area range are given by the manufacturer or calibrated.
3.10 Rated deflection
The maximum deflection value in the measuring screen area is defined as the rated deflection. 3.11 Effective screen area
The measuring screen area that can obtain the accuracy specified in 4.4 is called the effective screen area. Measurement can be performed outside the effective screen area, but the accuracy is reduced.
3.12 Recording speed
The recording speed is the maximum speed at which the oscilloscope's light spot can display a visible trace on the photographic film under certain conditions of use. 3.13 Warm-up time
The time from the oscilloscope being powered on to the oscilloscope reaching normal working state under the reference conditions of 4.1.1 is called warm-up time. In order to ensure the measurement accuracy under unfavorable working conditions such as low temperature and high humidity, the warm-up time can be appropriately extended. 3.14 Absolute error and relative error
Absolute error is the difference between the measured value and the comparison value; relative error is the ratio of absolute error to comparison value. It is usually expressed as a percentage, and the comparison value can be a true value or a conventional value.
3.15 Single error and total error of oscilloscope The single error of oscilloscope is the measurement error caused by a certain specified parameter or characteristic. The total error of oscilloscope is the combination of all single errors. Both the single error and total error of oscilloscope can be expressed by absolute error and relative error. 4 Technical requirements
4.1 Working conditions
4.1.1 Reference conditions
The various performance characteristics of the oscilloscope must be measured under the reference conditions specified in Table 1 and the basic accuracy of the instrument must be verified. Table 1 Reference conditions for AC power supply
Ambient temperature
Reference value
Allowable deviationbZxz.net
±2℃
Ambient relative humidity
Power supply voltage
Power supply rating
Atmospheric pressure
JB/T7089-93
Continued Table 1
45%~75%
220V(effective value)
86-106kPa
4.1.2 Normal use conditions
The oscilloscope should be able to work normally within the range of use conditions specified in Table 2 and meet the accuracy requirements. Table 2 Range of normal operating conditions
Ambient temperature
Ambient relative humidity
Power supply voltage
Power supply frequency
Atmospheric pressure
4.2 Safety requirements
Allowable deviation
±1% (effective value)
±2% (peak value)
+5℃~+40℃
10%~90%
, ±10% (effective value)
220V (effective value)
±12% (peak value)
50Hz±5%
70.0~106.0kPa
4.2.1 The safety of high-voltage oscilloscopes shall comply with the requirements for Class 1 electronic instruments specified in GB4793, except for those that must meet the requirements of this standard.
The high-voltage components inside the high-voltage oscilloscope must have good insulation measures, and discharge or ionization is not allowed. The shell and accessible parts of the oscilloscope should not be charged, and the operating parts on the panel should not be charged. The power input terminal of the oscilloscope should be able to withstand the impact of 30kV standard lightning waves to the ground terminal. The maximum input voltage of the oscilloscope measurement terminal is 1600V peak. The power input terminal and measurement input terminal of the oscilloscope should have internal overvoltage protection devices. The oscilloscope must be equipped with a grounding terminal and meet the following requirements: The grounding connection should not use a screwless terminal and have sufficient strength; the resistance value between the grounding terminal and the part required to be connected to it should not be greater than 0.5α; there should be a clear and durable grounding symbol "士" near the grounding terminal, and the symbol cannot be recorded on detachable parts such as screws.
Appearance quality of high-voltage oscilloscope
The shell of the oscilloscope should be flat and free of sharp thorns, and the shell coating should not have delamination and peeling. 4.3.1
4.3.2 The text symbols of various quantities and units on the oscilloscope panel should comply with relevant regulations, and the characters should be clear and not easy to erase. 4.3.3 All knobs and switches on the oscilloscope panel should be complete, reliable in operation, clear in steps, and accurate in positioning. 4.4 Requirements for measurement accuracy
The total measurement error caused by the oscilloscope should meet the following requirements: The measurement error of the impulse voltage (current) peak value is not greater than 2%; the time measurement error is not greater than 4%;
If the single error related to the total error (ei, et, es\***e.) is an independent random quantity, the statistical total error E. is E,=ei+ei+.+e.
JB/T7089-93
When the probability of the error being greater than E, is not greater than 5%, the estimated E, can be considered to be the maximum error. The allowable limit of the single error is shown in the limit required by 4.54.13. As long as the total error meets the requirements, individual single errors are allowed to exceed the limit required by 4.54.13. 4.5 Requirements for transmission characteristics
4.5.1 The square wave response of the oscilloscope must meet the following requirements: The rise time should meet
≤2 yuan fg
Where f. The highest oscillation frequency that may appear in the test product far4 (H,+H)
Where: c: The propagation speed of electromagnetic waves 300; m/μsH: The height of the impulse generator loop; m
H: The height of the wave head capacitor used, m
And t,≤0.03T.
T. 1. The shortest cutoff time expected for measurement, as defined in GB311.3. (2)
At the same time, the decay time constant of the square wave response should not be less than 100T,, or the decay of the unit square wave response should not be greater than 0.04 in 4T (i.e. the amplitude of the square wave response drops to 0.96 at most). T is the maximum shock wave half-peak time expected to be measured, as defined in GB311.3.
When the oscilloscope square wave response has oscillation, the overshoot of the square wave response should be less than 10%. 4.5.2 The upper cutoff frequency f should not be less than 2f., and the lower cutoff frequency should not be greater than 0.005/T. 4.5.3 The accuracy of the oscilloscope attenuation factor should not be less than 0.5%. 4.6 Requirements for deflection coefficient corrector
The amplitude voltage error should not be greater than 0.5%; the error of the time signal should not be greater than 1%. 4.7 Requirements for linearity
4.7.1 Requirements for vertical deflection linearity
When there is only one amplitude calibration voltage (except for the zero line, there is only one amplitude calibration trace), only one vertical deflection coefficient can be determined. At this time, the amplitude of the measured signal should be located near the calibration trace, otherwise, within the effective screen, the linearity of the vertical deflection should not be greater than 1%. If the number of amplitude calibration levels is increased, the measurement error caused by nonlinearity can be reduced, and the linearity requirement can be relaxed. Note: The amplitude of the measured signal should be located between the two amplitude calibration traces. 4.7.2 Requirements for horizontal (time) deflection linearity When there is only one time scale, the horizontal deflection linearity should not be greater than 2%. If the density of the time scale interval is increased, the measurement error caused by nonlinearity can be reduced, and the linearity requirement can be relaxed. Generally, when the time scale interval is 10, the linearity requirement can be relaxed to 10%. Note: Since geometric changes affect the vertical and horizontal linear errors, they must be reduced as much as possible. 4.8 Requirements for stability
When the working conditions remain unchanged, the stability of the oscilloscope deflection coefficient should not exceed the values listed in Table 3. Table 3 Requirements for stability
Use the calibrator for each photo
Vertical display
Horizontal display
Short-term stability
Long-term stability
Short-term stability
Long-term stability
Not applicable
Not applicable
Not applicable
After the oscilloscope is preheated, when each oscilloscope graph has amplitude and time scales, the short-term stability shall meet the above requirements for at least 30 minutes. When not every oscilloscope graph has amplitude and time scales, the oscilloscope shall be calibrated at least twice during the continuous use of the oscilloscope. The stability between the two calibrations shall meet the long-term stability requirements for 50
JB/T7089-93
otherwise, it shall meet the long-term stability requirements for at least 8 hours. If the instrument attenuator is not included when calibrating with the instrument internal calibrator, the long-term stability period should be longer, for example one year. The manufacturer should ensure the stability indicators listed in Table 3. 4.9 Requirements for input impedance
The impact measuring instrument is usually connected to the voltage divider or shunt through the measuring cable. When connected to the resistor voltage divider or shunt, the input impedance value should be equal to the wave impedance of the cable. When connected to the capacitor voltage divider or the resistor-capacitor voltage divider, the input impedance should be as high as possible. In general, the equivalent input impedance can be a resistor of not less than 1MQ in parallel with a capacitor of less than 50pF; at the same time, the instrument should generally have an internal or external impedance converter to obtain an input impedance that is the same as the cable wave impedance. Note: It must be noted that when measuring a shock wave with a very long duration with a capacitive voltage divider, the time constant of the low-voltage arm of the voltage divider is not long enough compared to the duration of the shock wave because the input impedance of the instrument is not large enough, and the voltage divider ratio and the scale factor of the measuring system cannot be considered constant; but as long as the voltage divider ratio changes within 5% during the half-peak time of the measured shock, it is sufficient to meet the requirement that the voltage divider ratio is constant (the change does not exceed 1%, see GB311.4) during the time when the measured shock reaches the peak value.
4.10 Requirements for DC power supply voltage pulsation The change in the deflection coefficient caused by the pulsation in any pulsation cycle of the DC voltage cannot be greater than 0.5%. 4.11 Requirements for the width of the recording trace
Under all specified conditions of use, the width of the recording trace should generally not exceed 1% of the rated deflection. 4.12 Requirements for the error in the reading process of the oscilloscope The error caused by the reading process of the oscilloscope should not exceed 1% of the rated deflection. 4.13 Allowable limit of interference
The oscilloscope should be tested for anti-interference ability. The deflection of the baseline caused by interference should not be greater than 1% of the expected deflection. A deflection exceeding 1% is allowed only when it is confirmed that the interference does not affect the measurement accuracy. 5 Performance test items
5.1 The technical data provided by the manufacturer or verified and determined by the user should be consistent with the provisions of SJ945. The following performance indicators are particularly important for oscilloscopes used for impact measurement:
Accuracy of amplitude scale voltage
Accuracy of time scale signal
Linearity of deflection coefficient
Determination of effective screen area
Transmission characteristics (including attenuator ratio and square wave response) Stability of internal attenuator
Maximum input voltage value and duration
Anti-interference test
The long-term performance verification and short-term verification tests of the following items should be carried out during use. 5.2
Accuracy of the calibrator;
Effective screen area;
Linearity (vertical and horizontal);
Transmission characteristics.
6 Performance test method
The following performance test is carried out under the reference conditions specified in 4.1.1, with the purpose of determining certain characteristics that may cause measurement errors. 6.1 Determination of calibrator accuracy
6.1.1 Determination of amplitude calibration signal
JB/T7089-93
The amplitude calibration signal is generally a DC voltage signal. The amplitude of the signal is directly measured using a digital voltmeter with an accuracy better than 0.1. The input impedance of the digital voltmeter should be high enough, generally greater than 10Mn. The amplitude error is: [(U,-U,)/U,JX100%
Where, U. : Nominal voltage standard value
U.: Digital voltmeter reading
The relative error between the test result and the nominal value shall meet the requirements of Article 4.6. 6.1.2 Determination of time standard signal
The time standard signal is generally a sine wave of equal amplitude, a peak pulse or a light and dark line. The time interval (or signal rate) in one cycle of the signal can be measured by a frequency meter with an accuracy higher than 1×10-*. Time standard error = [(T.-T,)/T,]×100% Where: T. is the nominal value of the time standard (ns/grid, us/grid, ms/grid) T, is the measured value of the rate meter (μs/cycle) Note: Here, "grid" means that the relative error between the time standard pulse interval test result and the nominal value shall meet the requirements of Article 4.6. 6.2 Linearity of deflection coefficient
6.2.1 Linearity of vertical deflection coefficient
Set the attenuator of the oscilloscope under test to the *X1" position, apply a series of known DC voltage signals with an accuracy higher than 0.1% to the input of the oscilloscope, manually trigger the oscilloscope to record the waveform, and the applied signal must evenly divide the effective area of the display screen, with 6 to 10 levels being appropriate. According to the known amplitude of the signal and the distance of the waveform displayed on the screen, the deflection coefficient Y of each waveform is obtained. , from Y; the deflection linearity of the vertical system is:
[(Ym.—Y,)/YJ×100%...
[(Ym-Y,)/YJX100%
Take the value with the largest absolute value in the above formula.
In the formula: Yim, Yini are the maximum and minimum deflection coefficients Y is the average value of the deflection coefficient
The test results should meet the requirements of Article 4.7.1. 6.2.2 Determination of the linearity of the horizontal deflection (time) system 8.Determination method 1
Set the oscilloscope under test at a fixed attenuation level (generally 1), input a standard square wave or standard sine wave signal with a known frequency into the oscilloscope so that 10 cycles can be displayed on the screen, record the waveform and analyze it, and obtain the horizontal deflection linearity: [(Tx-T>/T]X100%.
[(TT>/TJ×100%
Take the value with the largest absolute value in the above formula
Where: T, T. are the maximum and minimum deflection distances of one cycle in 10 cycles, and the average cycle deflection distance
b. Determination method 2
Set the oscilloscope under test at a fixed attenuation level (generally 1), use the internal time stamp signal determined in 6.1.2, manually trigger the oscilloscope to record the waveform and analyze it, and obtain the horizontal deflection linearity: [(T m*—T,)/T,J×100%
Take the maximum absolute value in the above formula
[(TT)/TJ×100%.
Wherein; T, Tm are the maximum and minimum deflection distances of one cycle in several cycles 52
T: is the average cycle deflection distance
JB/T7089-93
The results obtained by the two measurement methods a and b shall meet the requirements of Article 4.7.2. 6.3 Determination of transmission characteristics
6.3.1 Determination of attenuation ratio
Set the attenuator of the oscilloscope to be tested to "X1" and other gears in turn, input a DC signal with a known voltage accuracy of more than 0.1% into the oscilloscope to be tested, and use a digital voltmeter with an accuracy of not less than 0.1 and an input impedance of not less than 10Mn to measure the output signal of the attenuator, and calculate them respectively. Calculate the attenuation factor. The difference between the attenuation factor and the nominal attenuation factor shall comply with the provisions of Article 4.5.3. -KK.
Where: U, is the input voltage
U is the output voltage
K, is the measured factor
K. is the nominal factor
8 is the factor accuracy
6.3.2 Square wave response of oscilloscope
The fast-front square wave is input into the oscilloscope under test via a coaxial cable. The front edge of the attenuator output square wave is measured with a high input impedance wide-band oscilloscope. To ensure the authenticity of the measurement results, the output load of the attenuator, including the leads and vertical deflection plate, remains intact, and the test point is placed on the vertical deflection plate.
Input and output waveforms of the oscilloscope under test
Test requirements:
<3%);
The front edge overshoot of the input square wave should be less than 5% (i.e. × 100%<5%); the top unevenness should be less than 3% (i.e. % length × 100%
the output square wave front overshoot should be less than 10% (i.e. × 100%<10%);
the horizontal width from 10% to 90% of the steady-state amplitude (A) is the response time ts; in this test, the input square wave rise time t. should be less than 1/3 of the rise time of the oscilloscope under test, otherwise tuVe-t is corrected according to formula (12).
where: t, is the rise time measured by the oscilloscope under test t is the rise time of the input square wave signal
e. In order to reduce the measurement error, it is recommended to use an oscilloscope probe with an input impedance of 100Ma//2pF and a bandwidth greater than 100MHz; (12)
JB/T7089-93
r, the square wave response must be measured for each attenuator level. If the response characteristics of the oscilloscope are ignored, the above measurement can replace the measurement of the transmission characteristics of the whole machine, and the measurement results must meet the requirements of Article 4.5.
6.4 Determination of the effective screen area
The effective screen area is related to the size of the single error, the amplitude mark voltage level and the trace position, and the time mark interval density and position. For example, if the relevant single error reaches the limit value specified in 4.5 to 4.13, and there is only a zero line and an amplitude mark trace, and this amplitude mark trace is close to half of the rated deflection, the effective vertical deflection should be limited to 0:5 to 1 times the rated vertical deflection. Similarly, if there is only one time mark interval and it is located in the central part of the full screen scan, the effective horizontal deflection should be limited to the range of 0.3 to 1 of the full screen scan. The above range is the effective screen area, as shown in Figure 1. Within the effective screen area, the voltage and time measurement errors can meet the requirements of 4.4. If there are more than one amplitude mark trace or more than one time mark interval, when measuring within the effective area specified in Figure 1, the single error is allowed to exceed the specified value of 4.5~4.13. If the single error does not exceed the limit value of 4.5~4.13, the screen effective area can be increased; but when the effective vertical deflection is expanded to an area significantly lower than 0.5 and the horizontal effective deflection is expanded to an area significantly lower than 0.3, the reading error should be reduced. Measurements can be made outside the effective area of the screen, but the accuracy is reduced. YI
Horizontal effective screen area, time measurement error is not more than 4.0%
Vertical effective screen area
Voltage (current) measurement error is not more than 2.0%
Figure 2 Screen effective area
6.5 Anti-interference ability test
The instrument manufacturing department shall conduct the following four anti-interference ability tests on the oscilloscope, and the test results shall meet the requirements of 4.13. The interference level test of the entire measurement system including the oscilloscope under actual test conditions can be carried out by the user department. The test method is shown in Appendix B. 6.5.1 Test of transient quantity superimposed on the power supply voltage The transient quantity waveform can be an initial pulse with a rise time of no more than 100ns superimposed on a decaying oscillation with a frequency of more than 100kHz. The test circuit is shown in Figure 3. Its open circuit charging voltage U. should be no less than 5kV and the short circuit current should be no less than 200.A. 54
6.5.2 Electromagnetic field interference test
JB/T.7089—93
Connect to power supply
Figure 3 Power supply voltage superposition test circuit ground terminal
The instrument should have effective shielding for the fast changing electric field and magnetic field of 10kV/m and 1000A/m. The test circuit shown in Figure 4 can be used to generate interference magnetic field by discharging capacitors through the spherical gap; this circuit can generate square wave voltage with a rise time of about 50ns and attenuated oscillating current with a frequency of about 0.5MHz respectively.
Grounded metal plate
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The instrument is close to the lead end
Z-characteristic impedance
C=20 nF
6.5.3 Interference test between lines of two-line oscilloscope Electromagnetic field interference test
During electric field test
U. =40kV(R=Z)
During magnetic field test
U,=100kV(R=0)
For two-line oscilloscope, the deflection induced by the other ray should be recorded under the condition that one ray of the oscilloscope produces full-screen deflection, and the scanning speed is about 10us.
6.5.4 Trigger interference test
The trigger interference test should be carried out in two cases. The first is that no signal is added to the input end of the oscilloscope and it is open (no measuring cable), the time scan is about 104s, and the scanning trace is recorded under a certain trigger signal waveform and a given maximum allowable trigger voltage. The second is to apply a 1MHz to 5MHz sinusoidal voltage at the input end of the oscilloscope, the amplitude of which should be able to produce a vertical deflection of 5% to 10% of the full screen, and the time scan is also about 10us. The waveform of the sinusoidal oscillation is recorded under the above trigger voltage to observe the interference in the horizontal scan. 6.5.5 Evaluation of interference test
In the above four interference tests, if the vertical deflection caused by the interference is within 1% of the rated deflection, or the distortion of the recorded sinusoidal oscillation waveform can be ignored, the single anti-interference ability of the instrument is satisfactory. Failure to pass a single interference test indicates that the instrument is not suitable; however, passing a single interference test does not guarantee that the instrument can work satisfactorily under the actual impact test circuit. 55
6.6 Waveform measurement method
JB/T7089-93
When the linearity of the oscilloscope meets the requirements, a trace with amplitude marker can be used to determine the voltage amplitude. When the linearity requirements cannot be strictly met, in order to ensure the accuracy of the amplitude reading of the oscilloscope, 5 traces can be recorded simultaneously on an oscilloscope at the same scanning speed, as shown in Figure 4. The 5 traces are: trace 1 is the measured voltage trace, and the maximum vertical deflection on the trace is D. Trace 2 is the time marker trace;
Trace 3 is the trace when there is no input signal (zero line); Trace 4 is the trace of the amplitude marker voltage U, and its deflection is Di, D is less than D, Trace 5 is the trace of the amplitude marker voltage U, and its deflection is D, D, is greater than D,. D, and D, should be as close to D, as possible.
When the short-term stability of the deflection coefficient meets the requirements, traces 4 and 5 only need to be included in a few oscillograms, or only in the first and last oscillograms.
The peak value of the measured voltage is determined by formula (13): The waveform time is determined by formula (14):
U,=U,+
Trace 1
Trace 3
Figure 5 Example of oscilloscope scene measurement program
Trace 5
A1 Recommendations on full screen scan time and recording speed JB/T7089-93
Appendix A
Special recommended items
(Supplement)
The scan time of an oscilloscope ranges from 0.5uμs to 50ms and can be divided into 1, 2, and 5 scale magnifications. The scan time coverage range of an oscilloscope can be selected according to actual needs. The required recording speed is determined by the maximum steepness of the deflection to be recorded and the scan time used. The recording speed depends on the performance of the oscilloscope (accelerating voltage and phosphor type) and the recording system used (camera type, object-to-image ratio, film material, film processing method, etc.). When indicating the recording speed value, the camera and film used should also be indicated. The minimum recording speed and scanning time required for recording various impact waveforms on the oscillogram can be selected according to Table A1. The values in this table correspond to the "standard oscillogram size" of 6×10cm. When the recording oscillogram size is smaller than the "standard size", the actual required recording speed can be reduced according to the size ratio.
Determine the measurement system response time wavefront truncation impact 0.4μ by high-voltage square wave method
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