JJG 948-2018 Verification Regulation of Electrodynamic Vibration Testing Systems, English, Anglais, Englisch, Inglés, えいご
1 Scope
This regulation is applicable to initial verification, subsequent verification and in-service inspection of electrodynamic vibration testing systems (hereinafter referred as testing systems).
2 Normative references
The following documents are referenced in this regulation:
JJF 1156 Terminology and Definitions for Measurement of Vibration, Shock and Rotating Velocity
GB/T 7670-2009 Electrodynamic vibration generating systems (equipment) - Performance characteristics
For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
3 General
The electrodynamic vibration testing system is a dynamic mechanical environment test equipment used to generate different vibrations and shocks and other excitations (such as sinusoidal vibration, random vibration, sinusoidal broad band random vibration, narrow band random broad band random, classical shock, shock response spectrum, etc.) in accordance with the test standards. As shown in Figure 1, it is usually composed of digital vibration controller, electrodynamic vibration table, power amplifier, control accelerometer and other auxiliary equipment, etc.
Figure 1 Composition of testing system
4 Metrological performance requirements
This regulation covers the metrological performance requirements for various functions of testing system. If the testing system only has some functions, the performance verification of all the functions contained in the system must be conducted. For example, if only the sinusoidal vibration function is available, performance verification must be conducted on all sinusoidal vibration function items.
4.1 Vibration controller
4.1.1 The frequency indication error of vibration controller within an assigned frequency range as shown in Table 1.
Table 1 Frequency indication error
Frequency range Class A Class B Class C
f<100Hz ±0.05Hz ±0.1Hz ±0.5Hz
f ≥100 Hz ±0.05% ±0.1% ±0.5%
4.1.2 The harmonic distortion of sinusoidal signal of vibration controller does not exceed 0.1%.
4.1.3 The controlled dynamic range for random self-closed ring acceleration power spectrum of vibration controller shall be controlled at (59 to 61)dB..
4.1.4 The consistency between any two channels for multichannel vibration controller shall meet the requirements specified in Table 2.
Table 2 Consistency between channels
Class Class A Class B Class C
Amplitude ratio ≤ 0.1 dB ≤ 0.2 dB ≤ 0.3 dB
Phase displacement ≤1° ≤2° ≤3°
4.2 Sinusoidal vibration
4.2.1 The noise of testing system acceleration shall meet the requirements specified in Table 3.
Table 3 Noise of testing system acceleration
Contents
Introduction I
1 Scope
2 Normative references
3 General
4 Metrological performance requirements
5 General technical requirements
6 Control of metrological instruments
Annex A Testing of random signal
Annex B Verification certificate (inside pages) format
Annex C Verification result notification (inside pages) format
Annex D Format of verification records
