GRAS 48LA Manuale utente

LI0273 – 2 November 2020

Instruction Manual

GRAS 48LA and 48LX-1 UTP

Level and Frequency Calibration

Instruction Manual 48LA and 48LX-1 – Level and frequency calibration | 2

Revision History

Revision Date Description

1 2 November 2020 First edition

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.

Do not touch the diaphragm

Instruction Manual 48LA and 48LX-1 – Level and frequency calibration | 3

Contents

Introduction ......................................................................................................................4

Sensitivity Calibration ..........................................................................................................................5

Frequency Calibration ..........................................................................................................................6

Warranty, Service and Repair......................................................................................... 7

Warranty, Service and Repairs............................................................................................................ 7

Instruction Manual 48LA and 48LX-1 – Level and frequency calibration | 4

Introduction

Proper calibration requires the use of dedicated calibration equipment in a controlled environ-

ment, i.e. a laboratory or similar. For this purpose, we have developed two dedicated adapters

• RA4801 Adapter for sensitivity calibration of 48LA/48LX-1.

• RA4802 Actuator for frequency calibration of 48LA/48LX-1.

The RA4801 can be used with a pistonphone such as the GRAS 42AP Intelligent Pistonphone or

the GRAS 42AA Pistonphone.

The RA4802 is an electrostatic actuator for frequency calibration, integrated in a stand with a

mechanism for holding and locking the microphone during calibration.

The RA4802 requires connection to a proper supply and signal source. For this purpose, we rec-

ommend microphone calibration system, such as the GRAS 90CA Microphone Calibration System

which oers all the hardware and software required for proper laboratory calibration.

For further information, visit www.grasacoustics.com/90CA

Instruction Manual 48LA and 48LX-1 – Level and frequency calibration | 5

Sensitivity Calibration

Before calibration, the microphone must be connected to the analyzer to warm up. About three

minutes are required.

Neck for pistonphone

with ½"collar

Lever for holding and

releasing the microphone

Fig. 1. Mounting a UTP microphone in the RA4801 Adapter for sensitivity calibration of 48LA/48LX-1.

1. Insert the neck into the pistonphone's collar and tighten the collar.

2. While holding the pistonphone-adapter assembly at the top with one hand, insert the micro-

phone into the slot, with the backside turned upwards.

3. Turn the lever to lock the microphone.

4. Turn on the pistonphone.

Correction Factor (Pistonphone)

Frequency Correction Factor Accuracy

250 Hz 0 dB ± 0.2 dB

Calibration with the 42AG Multifunction Sound Calibrator

The procedure for using a 42AG is the same as described for a pistonphone.

Correction Factors

Frequency Correction Factor Accuracy

250 Hz -0.3 dB ± 0.2 dB

1 kHz -1.0 dB ± 0.2 dB

Instruction Manual 48LA and 48LX-1 – Level and frequency calibration | 6

Frequency Calibration

For frequency calibration, a setup like the one shown in Fig. 2 is needed, we recommend a com-

plete microphone calibration system like the GRAS 90CA Microphone Calibration System.

Power

G.R.A.S.

Actuator Supply

Type 14AA

AC Output

+200VDC

AC Output

Max. 1Vrms

+800VDC

AC Output

GND

AC Input

Overload

Signal generator 14AA Actuator Supply RA4802 Actuator Analyzer

48LA/LX-1

Fig. 2. Block diagram of a setup for frequency calibration

Procedure

When the calibration system and microphone are connected, proceed as described below.

Lever for holding

and releasing the

microphone

Electrostatic actuator

Slot for

microphone

Microphone

locked in place,

ready for

calibration

Fig. 3. The RA4802 Actuator for frequency calibration of 48LA/48LX-1.

1. With the RA4802 in the open position, place the microphone with the diaphragm facing

upwards in the slot as shown above.

2. Turn the lever to lock the microphone in place.

You are now ready to perform the calibration.

Instruction Manual 48LA and 48LX-1 – Level and frequency calibration | 7

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

www.grasacoustics.com/repair-center

WEEE directive:

2002/96/EC

CE marking directive:

93/68/EEC

Manufactured to conform with:

RoHS directive:

2002/95/EC

GRAS Sound & Vibration continually strives to improve the quality of our products for our

customers; therefore, the specications and accessories are subject to change.

Altri manuali per 48LA

Questo manuale è adatto per i seguenti modelli

Indice

Altri manuali GRAS Apparecchiature di prova

GRAS

GRAS 45CA-1 Manuale utente

GRAS

GRAS 90CA Manuale utente

GRAS

GRAS 43AG Series Manuale utente

GRAS

GRAS 43AC Manuale utente

GRAS

GRAS RA4803 Manuale utente

GRAS

GRAS 42AA Manuale utente

GRAS

GRAS 50GI-R Manuale utente

GRAS

GRAS 45CC Series Manuale utente

GRAS

GRAS 42AP Manuale utente

GRAS

GRAS AL0030 Manuale utente

Manuali Apparecchiature di prova popolari di altre marche

SMART

SMART KANAAD SBT XTREME 3G Series Manuale utente

Agilent Technologies

Agilent Technologies BERT Serial Manuale utente

Agilent Technologies

Agilent Technologies N3280A Manuale utente

Vernier

Vernier Go Direct Voltage Manuale utente

Lifeloc

Lifeloc R.A.D.A.R. Manuale utente

Fluke

Fluke T5-600 Istruzioni per l'uso e l'installazione

Mercury

Mercury TSL01 Manuale utente

MAHA

MAHA MBT Series Manuale utente

Fuji Electric

Fuji Electric P-61 Manuale utente

ETC

ETC SealerAtor Manuale utente

Skyfine

Skyfine ETHYWAY V2 Manuale utente

Appion

Appion G5 Twin Manuale utente

PCB Piezotronics

PCB Piezotronics 8159-0112A Manuale utente

BW Technologies

BW Technologies MicroDock II Manuale utente

Sun Nuclear

Sun Nuclear 1027 Manuale utente

Biomark

Biomark HPR LITE READER Manuale utente

Hioki

Hioki 3169-20 Manuale utente

Ashcroft

Ashcroft ATE-100 Manuale utente