BRUEL & KJAER 4294 - CHAPTER 1 Introduction

1
Chapter 1
Introduction
USES
• Precise field calibration of vibration transducers
• Rapid calibration and checking of vibration transducer sensitivity
• Quick, easy field calibration of vibration measurement and recording systems
FEATURES
• Small, lightweight, and battery-driven
• Leather case for impact protection
• Designed for everyday use in harsh environments
• Acceleration, velocity and displacement calibration
• High-precision, crystal-controlled servo operating at 159.15 Hz (1000 rad s
–1
)
• Drop- and environment-tested according to IEC 60068
• Splash-proof according to IP 54 (IEC 60529)
Description
Type 4294 enables accurate adjustment of measuring instrumentation at a standard acceleration
level of 10 ms
–2
(0 – 70 gram load). The reference signal can also be used for velocity and
displacement calibration at 10 mms
–1
and 10 µm, respectively.
Type 4294-002 enables accurate adjustment of measuring instrumentation at a standard
acceleration level of 3.16 ms
–2
(0 – 200 gram load). The reference signal can also be used for
velocity and displacement calibration at 3.16 mms
–1
and 3.16 µm, respectively.
The calibrator contains an electromagnetic exciter driven by a crystal oscillator at a frequency
of 159.15 Hz (1000 rad s
–1
). A small accelerometer on the underside of the vibration table
provides servo feedback to maintain a constant, accurate vibration level independent of the
mass of the transducer under test (maximum 70 gram for Type 4294 and 200 gram for
Type 4294-002).