Norsonic nor1218, Instruction Manual

Page 1: ...INSTRUCTION MANUAL Outdoor microphone nor1218 ...

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Page 3: ...Outdoor microphone nor1218 ...

Page 4: ...thermore Norsonic AS assumes no responsibility for any infringement of the intel lectual property rights of third parties wherever applicable which could result from such use Norsonic AS reserves the right to amend any of the informa tion given in this manual in order to take account of new developments If you wish to communicate with us please feel welcome Our address is Norsonic AS P O Box 24 N ...

Page 5: ...les and cable length 9 Directional response 10 Frequency response 11 Self noise and wind 12 Chapter 6 Connecting the Nor1218 to Sound Level Meter Nor131 or Environmental Noise Meter Nor139 13 Chapter 7 Maintenance 14 Chapter 8 Specifications 15 Mounting direction 15 Acoustic performance 15 General 15 Frequency response 15 Directional response 15 General 15 Conformity 16 Protection provided by the ...

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Page 7: ...ements according to IEC61672 1 and similar national standards for a sound level meter class 1 The microphone is intended for vertical mounting only since the act of gravitation forms a part of the rain pro tection system The reference direction may however be selected to be vertical or horizontal based on the applied frequency response compensation in the sound level meter The outdoor microphone m...

Page 8: ...he windscreen from this upper part as this may de stroy the weather protection and alter the acoustic per formance The unit is delivered with an adaptor for mounting on a tripod The cable is led through a slot in the side of the adaptor The base screw has a threaded hole like those commonly used for cameras 3 8 UNC The base screw also forms a tension relief for the cable Remove the base screw and ...

Page 9: ...e rod should be placed at least 25 cm to the side of the microphone assembly and have a diameter not more than 10 mm in order not to interfere with the directional properties of the microphone Safety considerations may require the screen of the microphone cable to be properly grounded and that the internal conductors are clamped for high voltage protection We recommend making the combined groundin...

Page 10: ...1 calibrator with a stated level of 114 dB This is only valid if the frequency response correction is turned off For the Nor131 and Nor139 the frequency correction is turned off when entering into the calibration menu Perform calibration and calibrate the microphone as a normal free field microphone I E 0 1 dB if using a 1000 Hz calibrator When leaving the calibration menu you will observe that th...

Page 11: ... dust mesh are made of a water repellent fabric open for the sound The sound is reaching the microphone through nine slots placed equidistantly around the circumference of the circular body of the upper part The mechanical part with the birdspike is also important for the directional response of the complete microphone system The upper part may be removed as one unit and will thus give easy access...

Page 12: ... in the field If disassembled in the field the performance may be reduced due to contamination from dust and hu midity When Nor1218 substitutes a normal measurement microphone on a sound level meter a correction of the frequency response is needed to retain the class of accuracy for the sound level meter see Specifications Based on the correction the reference direction may be selected to be eithe...

Page 13: ...system is therefore mainly deter mined by the microphone cartridge and the acoustic performance of the enclosure 0 1 1 10 100 Frequency Hz 1k 10k 100k 8 7 6 5 4 3 2 1 0 1 2 dB Typical frequency response for the preamplifier Nor1207 The combination of microphone and preamplifier has an additional typical attenuation of 6 dB relative to the open circuit sensitivity of the microphone ...

Page 14: ...ectrical noise when the microphone is substi tuted by an 20 pF capacitor is shown on the graph be low 0 dB corresponds to 1 µV For a microphone with a sensitivity of 50 mV Pa Nominal value of Nor1227 Nor1228 0 dB voltage also corresponds to the nor mal reference pressure for sound 20 µPa and the noise level may be compared with sound pressure level directly Typical self noise of the microphone sys...

Page 15: ...th of the ca ble A typical value for the Nor4531 microphone cable from Norsonic is 100 pF per metre Hence a cable with length 100 m will load the output with a capaci tance of 10 nF For lower frequencies there are seldom problems with long cables However when the signal contains the combination of high amplitude and high frequency the capacitive loading will lead to high out put current A limited ...

Page 16: ...onse The directional response of a microphone is the ratio of the free field response at a particular frequency as a function of angle of sound incidence to the response in the reference direction The upper adjacent figure shows the directional re sponse for Nor1218 when the reference axis is verti cal for the frequencies 1000 Hz 4000 Hz and 8000 Hz IEC 61672 1 specifies tolerance limits for any f...

Page 17: ...cified in the international standard IEC 61672 1 10 100 1k 10 k 20 k 30 25 20 15 10 5 0 5 10 Vertical Horizontal Sensitivity level dB Frequency Hz When the microphone system is used in connection with the precision sound level meter Nor131 or Nor139 for program version 3 0 and above select 1218 Verti cal or Horizontal in the input setup menu to enable the right settings If the large windscreen Nor...

Page 18: ...y The levels are measured without frequency compensation The correspond ing A weighted levels are 16 dB 40 dB and 48 dB Depending on the wind speed the noise levels are typically 20 dB to 30 dB lower than for an unprotected microphone 0 10 20 30 40 50 60 70 80 90 6 3 8 10 12 5 16 20 25 31 5 40 50 63 80 100 125 160 200 250 315 400 500 630 800 1 k 1 25 k 1 6 k 2 k 2 5 k 3 15 k 4 k 5 k 6 3 k 8 3 k 10...

Page 19: ...ical for Nor1218 for vertical fre quency correction to be applied and 1218 Horizontal for horizontal frequency correction If the large windscreen Nor4576 is fitted above the standard windscreen supplied with the Nor1218 an extra frequency compensation is needed This is only possible in the horizontal mode Select 2 corrections in the input menu and then 1 large windscreen in the next submenu to tur...

Page 20: ...ifted upward en sure that the lower part stay fixed otherwise the rain hood above may be harmed The outer part of the windscreen may be cleaned by washing by hand using standard household wash ing up detergents Ensure that it has been thoroughly rinsed in clean water and is completely dry before it is remounted Do not use excessive heat for the drying 85ºC maximum However we recommend to replace t...

Page 21: ...ise A weighted 18 dB re 20 µPa Z weighted 22 dB re 20 µPa 22 5 Hz 22 5 kHz Frequency response See Technical description Frequency correction is recommended for conform ance with the requirements in IEC 61672 for class 1 sound level meters Directional response The directional response satisfies the requirements for a Class 1 sound level meter according to IEC61672 1 See section 4 4 Directional resp...

Page 22: ...gory IP55 according to IEC 60529 DnV report No 2009 3124 Accessories and spare parts Windshield upper part Norsonic part no Nor4529 Assembled upper part with windscreen Norsonic part no Nor4560 Microphone Nor1227 or Nor1228 Microphone preamplifier Nor1207 Sound calibrator Nor1251 or Nor1253 Microphone cable Nor4531 Standard lengths 5 10 15 30 and 50 metres other lengths on request Dummy microphone...

Page 23: ...07 EN 6100 6 2 2005 Sound Applicable parts of IEC61672 1 Configuration for test Connected to Nor131 Nor139 and Nor140 sound level meters This product has been manufactured in compliance with the provisions of the relevant internal Norsonic production standards All our products are tested individually before they leave the factory This Declaration of Conformity does not affect our warranty obligati...

Page 24: ...r acoustics from sound calibrators micro phones and preamplifiers via small handheld sound level meters to advanced yet portable real time analysers but also building acoustics analysers and complete community industry and airport noise monitoring systems Contact your local representative or the factory for information on our complete range of instrumentation ...