Related Manuals for G.R.A.S. 90AA
Summary of Contents for G.R.A.S. 90AA
- Page 1 Instruction Manual G.R.A.S. Audiometer Calibration Systems 90AA/90AB www.gras.dk LI0039 – 5 July 2017...
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Page 2: Revision History
Revision History Any feedback or questions about this document are welcome at gras@gras.dk. Revision Date Description 19 December 2011 First publication 5 July 2017 42AG substituted for the obsolete 42AB Copyright Notice © 2011-17 G.R.A.S. Sound & Vibration A/S http://www.gras.dk Any technical documentation that is made available by G.R.A.S. -
Page 3: Table Of Contents
Contents Introduction .................. 5 Getting Started with the 90AA and 90AB .......... 7 Using this manual ................8 General tips for using the HW1001 ............. 9 Calibrating the HW1001 Audiometer Analyzer ......... 10 When to calibrate ..................10 Adjusting the scale settings ............... 10 Carrying out the calibration ................ - Page 4 Memory handling ................ 20 Memory structure ..................20 SD-card memory..................20 Select the device for storing ..............21 Storing a measurement setup ..............21 Retrieving stored setups and data .............. 23 Deleting files and folders in the memory ............. 23 Technical Specifications ..............
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Page 5: Introduction
Introduction This manual contains information about operating and calibrating the components of the 90AA and the 90AB. Due to their similarities, both products are described in this one manual. Both systems include the Audiometer System Calibrator HW1001. This portable system makes acoustical measurements of frequency and levels of the test signal, as well as harmonic distortion. - Page 6 The 6cc coupler setup (43AF) has a test jig and an ear simulator (RA0075) that is designed to follow the specifications of the IEC 60318-1 standard. The RA0075 is designed with a volume of 5.6 cm , which approximates the volume of 6 cm when a human ear is wearing a supra-aural earphone.
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Page 7: Getting Started With The 90Aa And 90Ab
Getting Started with the 90AA and 90AB Before you begin using your G.R.A.S. Audiometer Calibration System, use these lists to check that you have the following components. The 90AA packing list Included Items Part Number Ear Simulator Kit according to IEC 60318-1 & -2 43AA * 1"... -
Page 8: Using This Manual
Using this manual The following conventions are used in this manual. Menu navigation For the HW1001 Audiometer Calibration Analyzer, the menu navigation is described by each of the menus you must go through. For example, SETUP > 1 (Instrum.) > 1 (Storing) means press the SETUP button, then 1 on the number pad to choose the first item on the menu, and then 1 on the number pad to choose the first item on the new menu. -
Page 9: General Tips For Using The Hw1001
General tips for using the HW1001 Use the INC and DEC keys to increase or decrease the current setting of the parameter. Alternatively use the keypad to type in the required value, whenever applicable. When the # sign appears in the lower line of the display, you can type in data. If you use the number keypad, press ENTER before moving to the next field. -
Page 10: Calibrating The Hw1001 Audiometer Analyzer
Calibrating the HW1001 Audiometer Analyzer Calibration is done through the menus and buttons on the HW1001. No special tools are required. When to calibrate Calibration of the HW1001 should take place before a measurement session begins, or when required by the standards in use. Note: This step does not replace calibration with a sound calibrator because the sensitivity adjustment procedure will be unable to reveal possible microphone, preamplifier, or extension cable malfunctions. -
Page 11: Db Value
Pressure microphones must be adjusted to a value equal to the output level of the sound level calibrator. 5. Set the sensitivity. To set the sensitivity correctly, use INC and DEC while watch- ing the level read-out. Alternatively, you may enter the required sensitivity using the numerical keypad. -
Page 12: Calibrating Hda-200 Circumaural Earphones
Calibrating HDA-200 Circumaural Earphones The HDA-200 circumaural earphones are standardized earphones used with audiom- eters. They are also known as high-frequency earphones, headphones, and headsets. They must be calibrated with an ear simulator that is designed according to the IEC 60318-1 standard. -
Page 13: Calibrating The Sensitivity Of 43Aa
2. Use the force gauge to hold the top bar of the clamp at precisely a 90° angle to the vertical bar. In that position, measure the force as you turn the finger screw and adjust the force to 4.5 N. You may need a slightly different force for your particular measurement. - Page 14 4. Create an “As Found” certificate For the “As left” measurement: 1. Measure the Level, Frequency and Distortion at each test frequency at the preset level. 2. Create an “As Left” certificate LI0039 – 5 July 2017...
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Page 15: Calibrating Tdh-39 Supra-Aural Earphones
Calibrating TDH-39 Supra-Aural Earphones The TDH-29 supra-aural earphones are standardized earphones used with audiometers, also knowns as audiometric earphones, headphones, or headsets. They must be cali- brated with a 6cc coupler. Fig. 3. A typical setup with supra-aural earphones. Setting up a 6cc coupler calibration The steps for a 6cc coupler calibration are 1. -
Page 16: Calibrating The Sensitivity Of 43Af
2. Use the force gauge to hold the top bar of the clamp at precisely a 90° angle to the vertical bar. In that position, measure the force as you turn the screw and adjust the force to 4.5 N. You may need a slightly different force for your particular measure- ment. - Page 17 3. Enter the new corrections factors in the audiometer 4. Create an “As Found” certificate For the “As left” measurement: 1. Measure the Level, Frequency and Distortion at each test frequency at the preset level. 2. Create an “As Left” certificate LI0039 –...
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Page 18: Calibrating Insert Earphones
Calibrating Insert Earphones Insert earphones are another type of earphone used with audiometers. Calibrating the EAR 3A ear-insert Fig. 4. A typical setup with insert earphones. The 3A and 5A are de-factor standardized earphones, also known as ear inserts. They are calibrated with a 2cc coupler. Mounting the RA0113 in 43AF 1. -
Page 19: Calibrating The Microphone On The Jig
Calibrating the microphone on the jig Before measuring with the audiometer, calibrate the microphone on the jig. 1. Loosen and remove the ear simulator. This exposes the microphone. 2. Place the sound level calibrator over the microphone. 3. Make sure that the calibration level is 114.0 dB ± 0.1 dB. Now you can begin the measurement process. -
Page 20: Memory Handling
Memory handling The instrument has a large built-in, non-volatile memory which can hold large amounts of measured data and measurement setups. Data can also be stored on an SD card with up to 2 GB storage. Memory structure The memory structure of the HW1001 is quite similar to that of a PC using both folders and files. -
Page 21: Select The Device For Storing
4. Press the left cursor, then ENTER. 5. Scroll down to FORMAT and press ENTER. 6. Confirm the FORMAT selection and press ENTER. 7. Wait until the format operation has been completed before performing other actions on the HW1001. Select the device for storing Select either the internal memory or the optional SD card as the location for storing data. - Page 22 • Calendar/clock settings • Serial interface on/off and baud rate or USB-selection • Second weighting-network (C-weighting or Z-weighting) • Level range (Normal/High) • Units (dB or engineering units) • Correction on/off • Printer • Language (for print) • Instrument identification (Option 11) Mode dependent parameters The parameters that are not global can be adjusted in one mode of operation for the instrument without affecting the value of the same parameters in another mode of...
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Page 23: Retrieving Stored Setups And Data
The data will now be stored in a folder with the name of today’s date. If this folder does not exist, it will be created by the HW1001. The first file is given the number 0001, the next file is given the number 0002, and so on. If you choose to delete one of the files already stored, you will leave a gap in the file list. - Page 24 Deleting a single file 1. When you have found the file or folder to delete, make sure that it is selected, that is highlighted as white text on black background. 2. Press DEL. 3. Press ENTER. 4. You will be prompted to confirm your action. The cursor is positioned by default on CANCEL to avoid deletion of the wrong file.
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Page 25: Technical Specifications
Technical Specifications Unless stated otherwise, the specifications are for the complete audiometer analyzer 90AA equipped with the 40AG ½” pressure microphone and the 26AB preamplifier. Values are based on the sensitivity set to the nominal value for the microphone: –26.0 dB corresponding to 50 mV/Pa. - Page 26 Self-noise levels The self-noise is measured with the calibration set to –26.0 dB corresponding to a microphone sensitivity of 50 mV/Pa. For voltage input, the level 0 dB then corresponds to 1 mV. Typical values for the self-noise are 5 dB lower than the values stated. The noise levels are measured without light in the display.
- Page 27 • I–time-weighted sound pressure level Instantaneous Maximum Minimum • Integrated-averaged sound pressure level • Sound exposure level • Peak sound level • Exceeding level for F–time-weighted sound pressure level (cumulative distribution) Level distribution As an optional extension, the HW1001 may be fitted to calculate the exceeding level (cumulative level distribution) for the F time weighted level.
- Page 28 The primary indicator range for compliance with IEC 60651 type 1 is 24 dB to 117 dB. For compliance with IEC 60804 type 1, the linearity range is 24 to 137 dB, and the pulse range 24 dB to 140 dB, respectively Total range for measurement of C-weighted levels The linear operating range is identical to the total range.
- Page 29 • Accuracy: 0.3% (1/10 of indication) • Resolution: 0.1% Power supply The lower, right-hand button on the front of the HW1001 is the power button. Press quickly to turn the device on, but press and hold for more than one second to turn the device off.
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Page 30: Ac-Out
If the HW1001 is connected to an external DC source, the external source voltage will be displayed (EV). If the external power fails during a measurement without any internal batteries installed (or the installed batteries have no power left), the HW1001 will be turned off immediately without storing the ongoing measurement. - Page 31 USB interface • USB type: 2.0 • USB socket: B411 SD-Card and Data Storage You can use the SD card to store setup information, sound recordings, and measurement results. The memory size can be up to 2 GB. Measured data is stored in the internal memory of the HW1001 or on the SD-card. The internal memory is a flash memory that retains data without the battery.
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Page 32: Ordering Information
—RA0184 Force Gauge Audiometer Calibration System Suitcase KM0076 * * Applies only to the 90AB because this option is already included in 90AA. Calibration Before leaving the factory, all G.R.A.S. products are calibrated in a controlled laboratory environment using traceable calibration equipment. -
Page 33: Warranty
Warranty All G.R.A.S. products are made of high-quality materials that will ensure life-long stabil- ity and robustness. The 90AA/90AB is delivered with a 5-year warranty. Damaged diaphragms in microphones can be replaced. The warranty does not cover products that are damaged due to negligent use, an incor- rect power supply, or an incorrect connection to the equipment.