GRAS RA4800 Adapter for Sensitivity Verification of Flush Instruction Manual
- June 12, 2024
- GRAS
Table of Contents
- GRAS RA4800 Adapter for Sensitivity Verification of Flush Instruction
- Revision History
- Copyright Notice
- Trademarks
- Introduction
- Description
- Procedure
- Correction values
- Warranty, Service and Repair
- Warranty, Service and Repairs
- Read More About This Manual & Download PDF:
- References
- Read User Manual Online (PDF format)
- Download This Manual (PDF format)
GRAS RA4800 Adapter for Sensitivity Verification of Flush Instruction
Manual
Revision History
| Revision | Date | Description |
|---|---|---|
| 1 | 2 November 2020 | First edition |
| 2 | 15 June 2022 | Update Correction table with 40PS-1 values |
Copyright Notice
© 2020-22 GRAS Sound & Vibration
http://www.grasacoustics.com
Any technical documentation that is made available by GRAS is the copyrighted
work of GRAS and is owned by GRAS.
The content in this document is subject to change without notice. GRAS Sound &
Vibration is not liable or responsible for any errors or inaccuracies that may
appear in this document.
Trademarks
Any product names mentioned in this document may be trademarks or registered trademarks of their respective companies and are hereby acknowledged.
Introduction
The RA4800 is an adapter intended for in situ verħfication of flush and
surface microphones. When using the RA4800, there is no need for dismounting
the microphone from the structure on which it is mounted, and therefore it
allows for a very quick and convenient verħfication of the integrħty of the
measurement setup.
It will normally be used with a sound calibrator such as the GRAS 42AG
Multifunction Sound Calibrator.
Description
The adapter has three main features.
- It has a 1² stud/collar for fit with any GRAS calibrator fitted for use with an 1²
- It has a soft cushion similar to those found on circum-aural It creates a closed cavity over the microphone to be calibrated.
- It has four spacers that ensure (when the cushion is depressed) that the cavity is well-defined and will be the same from one calibration to the next.
Procedure
Before verification, you must ensure that the microphone is properly connected
and powered up.
__ When you have turned on the calibrator and pressed it down over the
microphone, you must keep
it there until the reading on the analyzer is stable.
Refer to the manual for 42AG for further information about how to operate the
calibrator.
Correction values
| 250 Hz | 1 kHz | Accuracy | |
|---|---|---|---|
| 40LA | – 0.6 dB | -2.1 dB | ±0.2 dB |
| 40LS | – 0.6 dB | -2.1 dB | ±0.2 dB |
| 40PS-1 | 0.03 dB | 1.43 dB | ±0.29 dB*, ±0.44 dB† |
| 48LA | -0.8 dB | -3.0 dB | ±0.2 dB |
| 48LX-1 | -0.8 dB | -3.0 dB | ±0.2 dB |
| 48LX-4 | -0.8 dB | -3.0 dB | ±0.2 dB |
| 48LX-8 | -0.8 dB | -3.0 dB | ±0.2 dB |
- @ 250 Hz
† @ 1 kHZ
Warranty, Service and Repair
Warranty, Service and Repairs
GRAS products are made of components from our proven standard portfolio and
are all manu- factured of high-quality material and branded parts that were
chosen and processed to ensure life-long stability and robustness.
The warranty does not cover products that are damaged due to negligent use, an
incorrect power supply, or an incorrect connection to the equipment.
Further information about warranty and our repair service can be found at
grasacoustics.com/repair-center
GRAS Sound & Vibration continually strives to improve the quality of our
products for our
customers; therefore, the specifications and accessories are subject to
change.