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Instruction Manual

www.gras.dk

LI0196 – 19 July 2017

G.R.A.S. 42AG Multifunction Sound Calibrator 

Содержание 42AG

Страница 1: ...Instruction Manual www gras dk LI0196 19 July 2017 G R A S 42AG Multifunction Sound Calibrator ...

Страница 2: ...tp www gras dk Any technical documentation that is made available by G R A S is the copyrighted work of G R A S and is owned by G R A S The content in this document is subject to change without notice G R A S Sound Vibration A S 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 r...

Страница 3: ... 6 Using the 42AG 7 Microphone Calibration 7 Calibration Considerations 9 Accuracy 9 Background Noise 9 Corrections 9 Maintenance and Calibration 11 Replacing Batteries 11 Calibrating the 42AG Sound Calibrator 11 Adjusting the 42AG s Levels 11 Delivered Items 13 Technical Specifications 13 Warranty Service and Repair 14 ...

Страница 4: ...uded in the delivery Green LED lights when calibration level is OK Automatic compensation for ambient air pressure temperature and humidity Measurement of ambient air pressure temperature in C or F and humidity Automatic power off after 10 to 20 seconds Automatic shut off when batteries are too low About this Manual This manual contains the main sections listed below When referring to 42AG s butto...

Страница 5: ...ibrator complies with IEC 60942 2003 Class 1 and has been designed to serve 1 and smaller microphones and sound level meters equipped with such microphones 42AG is designed for use in the field The accuracy that can be achieved is within 0 2 dB which is more than adequate for field checks For proper laboratory calibration we recommend the use of a pistonphone or sending the micro phone to a calibr...

Страница 6: ... during power on Hz Toggles between 1 kHz and 250 Hz Default is 1 kHz dB Toggles between 94 dB and 114 dB Default is 94 dB Status Indicator Lights green when the pressure in the coupler has stabilized Display Displays the actual values for calibration and ambient conditions o N l a i r e S 888888888 G R A S 42AG Multifunction Sound Calibrator ANSI ASA S1 40 2006 R2011 Class1 IEC 60942 Batteries 2x...

Страница 7: ... frequency is indicated in the display of the calibrator After powering the sound calibrator the first combination of frequency level is 94 dB re 20µPa and 1 kHz Select the appropriate level and frequency for your calibration by pressing dB or Hz respectively Normally the background level should be more than 20 dB lower than the level from the calibrator in order to not influence the reading There...

Страница 8: ...output voltage is Vo and the sound pressure level in the Pistonphone s coupler is LC decibels the microphone sensitivity S is given by Vo 20 μPa 10 Lc 20 S The value 20 μPa is the standard reference sound pressure The result here includes the load ing effect of the preamplifier s input impedance as well as the gain or attenuation within the preamplifier To measure the Open Circuit Sensitivity of t...

Страница 9: ... to the nominal level Nevertheless it is considered good practice to note the ambient calibration conditions as part of each calibration routine Temperature The temperature may be displayed in either degree Celsius C or degree Fahrenheit F ln order to change the unit keep the button Met depressed during power on Load Volume Various types and makes of microphones may have different effective load v...

Страница 10: ...ree field microphone is designed to compensate for the pressure build up that takes place when it is used in a free field When calibrated with a sound calibrator at 1 kHz the output from the microphone will be lower compared to the output at free field conditions because the calibrator performs a pressure calibration of the microphone Therefore the result of a calibration of a free field microphon...

Страница 11: ...ivities at the different frequencies are known with a sufficiently high accuracy Adjusting the 42AG s Levels Caution It is possible to adjust 42AG s levels the SPL the displayed temperature air pressure and relative humidity However if you do this you will invalidate the factory calibration and break the link to previous measurements For this reason we have sealed the access to this function which...

Страница 12: ...ashing 3 While the display is flashing press Hz to increase the reading or dB to reduce the reading 4 When the correct value is displayed press Met and the value for air pressure starts to flash 5 While the display is flashing press Hz to increase the reading or dB to reduce the reading 6 When the correct value is displayed press Met and the value for humidity start to flash 7 While the display is...

Страница 13: ...evel 94 dB 0 2 dB 114 dB 0 2 dB Distortion 2 0 Sensitivity to environmental conditions IEC 60942 Class 1 Display of temperature air pressure and humidity Temperature 10 C to 50 C accuracy 2 C resolution 0 1 C Atmospheric pressure 65 kPa to 108 kPa accuracy 0 4 kPa resolution 0 1 kPa Relative humidity 25 to 90 accuracy 6 resolution 1 Microphone sizes 1 1 2 1 4 1 8 Power Two 1 5V LR03 AAA Size alkal...

Страница 14: ...are damaged due to negligent use an incorrect power supply or an incorrect connection to the equipment Service and Repairs All repairs are made at G R A S International Service Center located in Denmark Our Service Center is equipped with the newest test equipment and staffed with dedicated and highly skilled engineers Upon request we make cost estimates based on fixed repair categories If a produ...

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