BS 7285(1990) : 1990

Committees responsible
National foreword
Method
0. Introduction
1. Scope and field of application
2. References
3. Symbols
4. Units
5. Definitions
6. Characteristics to be supplied by the manufacturer
7. Hydraulic vibration generators
8. Control system
9. Hydraulic power system
10. Hydraulic vibration generator system
Annexes
A. Schematic diagrams
B. Methods for measuring or calculating various
     hydraulic vibration generator parameters
C. Selection of test mass
D. Servovalve control device
Tables
1. Values for displacement and acceleration PSDs
2. Vibration generator
3. Control system
4. Hydraulic power system
5. Complete hydraulic vibration generator system
6. Initial mode for a homogeneous test mass
Figures
1. Total distortion at a fixed frequency as a function
     of the acceleration
2. Total distortion as a function of the frequency at
     maximum acceleration for a given test mass
3. Example of system and single hydraulic stage
     servovalve drive requirements
4. Examples of rated sinusoidal characteristics
5. Example of a power spectral density acceleration
     (PSDa) profile
6. Schematic diagram of hydraulic test equipment for
     generating vibrations
7. Hydraulic linear vibration generator
8. Schematic diagram of a hydraulic power system
9. Boundary area defining values of D and L for
     different maximum operating frequencies
10. Typical servovalve control system block diagram

Hydraulic test equipment used for generating vibration has a wide range of characteristics. This standard establishes a list of the characteristics and the standard method of obtaining certain of these characteristics. Applies to hydraulic vibration generators, the servovalve control devices, the hydraulic power systems and the complete hydraulic vibration generator systems. Covers introduction, references, symbols, units, definitions, characteristics to be supplied by the manufacturer, hydraulic vibration generators, control system, hydraulic power system, hydraulic vibration generator system, schematic diagrams, methods for measuring or calculating various hydraulic vibration generator parameters, selection of test mass and servovalve control device.