User manual for the CR:261S Sound Level Meter
Contents
1. 51 Cirrus Research Offi CES wesc ne rec ec e Oo e X e ED P c Canta P o GO e EE cl 51 CR 261S Vehicle Noise Sound Level Meter Page 5 Preface Thank you for purchasing the CR 261S Series Sound Level Meter This instrument has been designed to be simple to use and to provide the functions and features needed from a modern Sound Level Meter This manual describes the procedure that should be followed to set up and operate the CR 261S Sound Level Meter as well as comprehensive technical information using optional accessories as well as troubleshooting If you are a new user of Sound Level Meters or new to the CR 261S Sound Level Meter first read Section 1 Introduction to familiarise yourself with the features components and accessories supplied Then read Section 2 Getting Started for step by step instructions on how to use the instrument Specification Standard Instrument Time Weighting Fast Frequency dB A Weighting Run Time Manual Measurements LAF Sound Level dB A Fast Time Weighting Larmax Maximum Sound Level dB A Fast Time Weighting Measurement Duration The CR 261S Sound Level Meter meets the requirements for IEC 61672 1 2003 standard for Class 1 Group X in all its modes Please refer to page 31 for full technical details of the CR 261S Sound Level Meter Manual Contents This manual is composed of the following sections Section 1 Introduction is an overvie2. 130 E Unstable The calibration level is unstable This maybe caused by high Not Calibrated background noise levels Move to a quieter location and retry the calibration Reset to measure To Remove the calibrator gently pull the calibrator whilst twisting the calibrator clockwise This will help to ensure that the microphone capsule does not become unscrewed from the instrument For more information refer to Appendix 4 Acoustic Calibrators Changing the Calibration Level The calibration level of the Sound Level Meter can be adjusted from the default level of 93 7dB To change the calibration level press and hold the Cal key for more than 2 seconds GO 130 l Press Cal to change level 93 7 Then Press Reset Use the Reset Key to cycle up through the levels Press CAL to accept the new level and to return to the main operation of the Sound Level Meter Setting the measurement range The CR 261S only has the one range which is 60 130 dB It is vital that the noise to be recorded is within this range otherwise the instrument will be in Overload or in Under range CR 261S Vehicle Noise Sound Level Meter Page 15 Setting the measurement modes Single Measurement Mode In Single Measurement Mode the instrument displays Lar and Larmax In this mode the instrument is controlled by the keypad Pressing the Reset key will reset the run duration and the Larmax hold value Multiple Measur
3. CR 261S Vehicle Noise Sound Level Meter Page 45 CR 261S Directional Response 0 30dwg Vertical with Windshield 100 1000 10000 100000 Frequency Hz o 0V WS 10V WS 20V WS 30V WS Page 46 CR 261S Vehicle Noise Sound Level Meter Influence of the UA 237 Windshield Influence of the windscreen on the frequency response with different angles 1 00 0 50 0 00 0 50 1 00 1 50 2 00 2 50 100 1000 10000 100000 0H 10H 20H 30H 40H 50H 60H 70H 80H 90H 100H 110H 120H 130H 140H 150H 180H Attenuation dB CR 261S Vehicle Noise Sound Level Meter UA237 windscreen influence on frequency response with 0 degrees Odeg and average attenuation over all directions AVG 0 60 0 40 Page 47 0 20 0 00 0 20 0 40 0 60 0 80 1 00 1 20 100 1000 10000 Frequency Hz AVG 0deg 100000 Page 48 CR 261S Vehicle Noise Sound Level Meter Data Table Frequency Hz UA 237 Windshield Free Field Microphone Response Pressure Freefield Case Reflection Data for Correction dB dB typical Correction dB CR 261S dB 10 0 03 0 25 0 22 0 13 0 03 0 27 0 22 0 16 0 03 0 29 0 22 0 20 0 03 0 3 0 22 0 25 0 03 0 3 0 22 0 32 0 03 0 3 0 22 0 40 0 03 0 3 0 22 0 50 0 03 0 3 0 22 0 63 0 03
4. 0 28 0 21 0 79 0 03 0 23 0 21 0 100 0 03 0 2 0 21 0 126 0 03 0 18 0 2 0 158 0 03 0 14 0 2 0 200 0 03 0 1 0 19 0 251 0 04 0 09 0 18 0 316 0 04 0 07 0 17 0 398 0 05 0 06 0 15 0 501 0 06 0 04 0 13 0 2 631 0 09 0 03 0 1 0 2 794 0 13 0 02 0 06 0 1 1000 0 17 0 01 0 0 1059 0 18 0 04 0 01 0 1122 0 21 0 11 0 03 0 1 1189 0 22 0 12 0 05 0 2 1259 0 23 0 13 0 08 0 2 1334 0 25 0 16 0 1 0 2 1413 0 28 0 0 13 0 2 1496 0 30 0 02 0 16 0 2 1585 0 32 0 05 0 19 0 2 1679 0 32 0 02 0 22 0 2 1778 0 33 0 0 26 0 2 1884 0 35 0 02 0 3 0 1 1995 0 35 0 04 0 34 0 2113 0 38 0 05 0 39 0 1 2239 0 42 0 05 0 45 0 1 237 0 45 0 05 0 5 0 1 2512 0 42 0 04 0 56 0 2661 0 43 0 03 0 63 0 1 2818 0 39 0 02 0 71 0 2 2985 0 34 0 05 0 79 0 1 3162 0 27 0 07 0 87 0 3350 0 16 0 08 0 97 0 3548 0 13 0 08 1 07 0 1 3758 0 02 0 07 1 18 0 1 3981 0 15 0 06 1 3 0 2 4217 0 05 0 02 1 43 0 1 4467 0 17 0 01 1 57 0 1 4732 0 13 0 02 1 72 0 2 5012 0 15 0 05 1 88 0 2 5309 0 06 0 06 2 05 0 1 5623 0 02 0 07 2 24 0 5957 0 09 0 07 2 44 0 1 6310 0 01 0 08 2 65 0 1 6683 0 13 0 06 2 87 0 2 7079 0 22 0 03 3 11 0 2 7499 0 29 0 01 3 37 0 1 7943 8414 8913 9441 10000 10593 11220 11885 12589 13335 14125 14962 15849 16788 17783 18836 19953 0 38 0 26 0 28 0 29 0 49 0 50 0 55 0 67 0 62 0 69 0 83 0 79 0 91 1 13 1 13 1 06 1 39 CR 261S Vehicle Noise Sound Level Meter 0 05 0 16 0 2
5. 31 5 Hz 63 Hz 125 Hz 250 Hz 500 Hz 630 Hz 800 Hz and 1000 Hz the lower limit of the linear working area for frequency weighting A is increased to 75dB For mechanical vibrations with an acceleration of 1m s parallel to the level of the membrane the lower limit of the working area for a frequency weighting A is increased to 64dB External Connections External switch connected via 8 pin mini DIN Output Cables ZL 261S Electromagnetic Performance EN 55022 1998 EN 61000 4 2 1995 EN 61000 4 3 2002 EN 61000 4 8 1994 Page 34 CR 261S Vehicle Noise Sound Level Meter Appendix 3 Further Information The unit s function is not affected by electrostatic discharges at 4kV contact discharges and 8kV air temperature increase The highest sensitivity to voltage change occurs if the antenna aerial is pointing towards the LCD screen via polaristion of the antenna aerial in the longitudinal axis of the sound level meter with the external cable connected and coiled in a figure eight configuration The meter s self noise is neither affected by external factors nor by the meter s configuration This is the case for both acoustic and electrical self noise The mini DIN socket is designed only for use by the manufacturer for test purposes Dummy microphone impedance of the microphone is 18pF in series with an input impedance of 50 ohm Such impedance can be supplied by the manufacturer as KP 66 The external cable for remote c
6. An instrument for measuring various noise parameters Sound Pressure Level the basic measure of noise loudness expressed in decibels Laboratory amp Field Grade for Sound Level Meters General Field Grade for Sound Level Meter The input to the Sound Level Meter is too low for the current measurement range Change the range Page 28 CR 261S Vehicle Noise Sound Level Meter Appendix 1 Rating Plate Information The CR 261S meets the requirements of IEC61672 1 2002 These specifications require that this manual provides detailed information to verify that the specifications are met While much of the data required is in the body of this manual the points required to be detailed are listed below in the order in which they occur in the IEC specification The CR 261S Sound Level Meter meets the requirements for IEC 61672 1 2003 standard for Class 1 Group X in all its modes The MK 226 Type 1 Electret microphone is the only microphone used with the CR 261S The reference direction of incidence is parallel to the sides of the case towards the microphone capsule The range of measurement for SPL measurement with a standard assembly is 60 to 130 dBA 60 to 130 dBC The self noise is both with A and when C evaluation under 54 dB C Weighting is provided for testing purposes This applies with the ZL 261S Remote Control Cable attached For signals with a crest factor of up to 10 the top span of the unit can be reduced by up to 17dB T
7. Instrument has two main modes the first being single measurement mode the second being multiple measurement mode Single Measurement Mode In Single Measurement Mode the instrument displays Lar and Larmax In this mode the instrument is controlled by the keypad Multiple Measurement Mode In Multiple Measurement Mode the instrument displays the currnet Larmax and the last two Larmax S In this mode the instrument is controlled through a push button on a lead that connects to the bottom of the instrument Options amp Accessories The CR 261S also available with a range of options and accessories that can enhance the performance and applications of the instrument For full details please contact Cirrus Research plc or your local representative The most commonly used accessories are listed below CR 511F Acoustic Calibrator with PTB Type Approval CR 590 Barometer for use with CR 511F Acoustic Calibrator UA 237 Windshield CK 250 Carrying Case CP 65 Carrying Pouch for Sound Level Meter CT 1 Tripod ZL 261S External Remote Control Cable 5m Page 8 CR 261S Vehicle Noise Sound Level Meter Section 2 Getting Started How to These example settings are designed to demonstrate the different configurations that are available from the CR 261S Sound Level Meter Make a Single Mode Measurement Switch on Calibrate Press the Reset Key Make Multiple Measurements Switch on Calibrate Insert external switch cable Hold
8. T WEE IRER E 32 Temperature sosna ninsi aa Er eat taaccd aa ia saaabeaeiae QUIE nes EPIS EISI a ans dace A EnA ka PURA EEEE UIDI FEE EE M 32 Humidity REL 32 Influence of Mechanical Vibration sse nnn nnns 33 External sCOnMECtion us eres XE rex ec ere xe nee dev er d Ex RE cer Y dk dc atdee renale 33 Output Cables mainii 33 Electromagnetic Performarice ite ea e eR seven yorkie e REA DEXR REX ERR ERRAT aaa a A 33 Appendix 3 Further nformation eee eee eee eee einen enne u neun unma nma n nun u nana n nana nnn 34 Overload Levels 2 osse euer rrt depen ex Rr ERE eR cults A da TERRENO ER ER senda busta ENS 34 CR 261S Directional Sensitivity cerei rere rhet a han ERR NR ecb ded ERERERRERDRRIR IR IRE ERE Ray ruina 36 Horizontal 2 24 nan eie eeiiurula oic pes aa sa esie exc ups ge regere Dr bee ce P eei ball wid evs Mace luadw pene ga dude 37 Vertical c Dc c tan a tae hae 39 Directional Sensitivity with UA 237 Windshield cece cece erect eee eee neat ene e nee ne ees 42 Influence of the UA 237 Windshield cccccccceesee eset nsec ee eee eee ee ae eens ease eeeeeeeaeenaennaneenees 46 DataTable sig nO ETE Ep 48 Appendix 4 CE Certificate of Comformance eeesseseseesea se nna unma naue annu 50 Equipment DESCrIPU ONS seii aam ea etx ere xx rx gassing DE TEO alegra uae ENTER HM E rA ERE Gu WR A a 50 CIIIICHI c MM
9. The calibration fails Too Low The Acoustic Calibrator is not switched on Switch on the Acoustic Calibrator and retry The Acoustic Calibrator is not fitted correctly Check that the Acoustic Calibrator is fitted according to the instructions supplied The microphone capsule is loose or not fitted Check that the microphone capsule is tight and fitted correctly Calibration level set to a different level Set the calibration level to the value provided by the Acoustic Calibrator The Microphone may be damaged Contact Cirrus Research plc or your local representative for assistance The calibration fails Too High The Acoustic Calibrator is set to a higher level than the expected level Set the Acoustic Calibrator to the correct level The calibration fails Unstable The background noise level is within 15dB of the calibration level Move to a location where the background noise level is more than 15dB below the calibration level The Microphone may be damaged Contact Cirrus Research plc or your local representative for assistance Page 26 CR 261S Vehicle Noise Sound Level Meter Measurements amp Settings Symptom Possible Cause Possible Remedy Overload symbol is shown The noise level is too high for the current range Under Range symbol is The noise level is too low shown for the current range Section 7 Glossary A Weigh
10. continuous use for average readings at 20dB below top of scale and at reference conditions This value will vary dependant on the quality of the Alkaline batteries used and will diminish if levels near top of scale are constantly monitored or if the batteries are at a low temperature Dummy microphone impedance is 18 pF in series with 50ohm Primary indicator range is 55dB to 95dB on the centre reference range An overload will always occur before non linear distortion takes place and before the linearity range is exceeded The microphone and associated electronics will be undamaged by sound levels in excess of 160dB The greatest peak to peak voltage applied electrically without damaging the SLM should not exceed 15V The Sound Level Meter corresponds the requirements of IEC 61672 1 2002 regarding RF Immunity and EMC Emmissons Page 30 CR 261S Vehicle Noise Sound Level Meter Calibration can be performed under the extremes of conditions within which the SLM meets the requirements of 61672 There is no AC output available on the CR 261S The microphone preamplifier is not removable A special RS232 cable and communication protocol can be provided on request for use by approved Test Houses requiring to access the continuous LAF level and LAFmax in either A weighting or C weighting for Pattern Approval purposes The operating mode that produces the highest RF emissions is when the unit is running with the ZL 261S cable attached coi
11. down the button to start measurement Release the button to end measurement Repeat Quick Start The information in this section is the same as that given in the CR 261 Quick Setup Guide For more detailed information please see section 3 1 Switch On Press the Power button to switch C r r on the Sound Level Meter I u S Research plc CR 261S 1 00 The instrument will display the start up screen and then will 60 130 f display the Single Mode screen LAF OB _LAFMax dB utl Oc n D JW Uu u t 00 01 23 CR 261S Vehicle Noise Sound Level Meter Page 9 2 Calibration Attach the Acoustic Calibrator to the Sound Level Meter and switch to the 94dB level setting Press the Cal key to start the calibration procedure Cal N Attaching the Calibrator EN Gently push and twist the When the calibration is complete calibrator clockwise the display will change to show the calibration level Remove the Acoustic Calibrator Calibrating switch off the calibrator and store Please wait 3 Mode Select With the cable not plugged in the instrument runs in single measurement mode 7 With the cable plugged in the a instrument goes into multiple 130 M 60 mmi 130 T measurement mode LAFmax dB LAFmax LAFmax LAFmax 05 5 Page 10 CR 261S Vehicle Noise Sound Level Meter 4 Start Measurement 60 sum 130 j Single Measurement Mode
12. ee Pressing the Reset key on the N keypad clears the Larmax hold o Ji X functions and starts a new LAFMax dB goH measurement t 00 01 23 Multiple Measurement Mode When the cable is inserted and C0 t 130 F the button is held in it displays the LAFmax value when the A g button is released and the dB dB dB depressed again it moves the last LAFmax value to the next t 00 01 23 slot along and then starts a new measurement 5 Switch off Press and hold the Power button to switch off the instrument CR 261S Vehicle Noise Sound Level Meter Page 11 Section 3 Using the CR 261S Sound Level Meter Unpacking and checking the Sound Level Meter Carefully remove the instrument from its shipping container and inspect it for possible damage or missing items If the meter appears to be damaged or something is missing contact Cirrus Research plc or your local representative immediately The CR 261S instrument is supplied with the following standard accessories CR 261S User Manual Batteries 2 x AA If you have ordered the instrument as a complete measurement kit you will have also received some further items such as an Acoustic Calibrator Carrying Case and Windshield Please refer to the manual supplied with the Acoustic Calibrator where supplied for details of fitting the battery and operation of this unit Batteries The batteries of the CR 261S are located behind the cover on the bottom of the
13. symbol will disappear t 00 01 23 CR 261S Vehicle Noise Sound Level Meter Page 17 Section 4 Vehicle Noise Measurements If measurements are being made in accordance with ISO 5130 or any other Standard Regulation or Guideline always refer to the appropriate documentation for test procedures and any other relevant information The information contain in this section is provided as a general guide as to the use of the CR 261S Sound Level Meter for vehicle noise measurements Reference to ISO 5130 in this manual refers to ISO 5130 1982 Text in italics below has been taken from the ISO 5130 1982 standard but is not a verbatim copy of the text in the standard Always refer the any Standard Regulations or Guidelines for details of test procedures the must be followed Overview Test Site To reduce the influence of the surroundings on the noise measurements a test site meeting the following requirements shall be used Any open space may be considered to be a suitable test site if it consists of a flat area made of concrete asphalt or hard material having a high acoustical reflectivity excluding compressed or other earth surfaces The edges of the test site shall be at least 3m from the extremities of the vehicle and there shall be no feature or object present on the test site likely to affect the reading of the Sound Level Meter in particular the vehicle shall be at a distance of not less than 1m from a pavement edge when
14. 6 0 39 0 52 0 61 0 7 1 1 3 1 61 1 92 2 24 2 55 2 82 3 08 3 5 3 91 3 63 3 92 4 21 4 53 4 86 5 21 5 57 5 97 6 39 6 85 7 36 7 93 8 6 9 39 10 35 11 55 13 08 0 1 0 1 0 1 0 1 0 2 0 2 0 2 0 3 0 4 0 3 0 4 0 4 0 4 0 4 0 4 0 4 Page 49 Page 50 CR 261S Vehicle Noise Sound Level Meter Appendix 4 CE Certificate of Comformance CE Manufacturer Cirrus Research plc Acoustic House Bridlington Road Hunmanby North Yorkshire YO14 OPH United Kingdom Telephone 44 1723 891655 Cirrus Research plc Hunmanby UK CE Certificate of Conformity Equipment Description The following equipment manufactured after 1 January 2006 CR 261S Sound Level Meter Along with their standard accessories According to EMC Directives 89 336 EEC und 93 98 EEC meet the following standards EN 50081 1 1992 Generic emission standard for residential commercial and light industry EN 50082 1 R Immunity implies sound level indications will not be affected by more than 0 5dB at a background level of 74dB A or less Signed dated 1st March 2006 SC S ORourke Director CR 261S Vehicle Noise Sound Level Meter Page 51 Guarantee Cirrus Research plc offers a 24 month guarantee on all of their units This covers all parts and labour excepting only damage caused by the user Because of the unique fragility of microphones only internal short or open circuits are accepted as faults and no
15. CR 261S Vehicle Noise Sound Level Meter Page 1 User Manual for the CR 261S Vehicle Noise Measurement Sound Level Meter Cirrus Research plc This manual the software to which it relates the program code and drawings are all Copyright Cirrus Research plc 1989 2007 Page 2 CR 261S Vehicle Noise Sound Level Meter The content of this manual any illustrations technical information and descriptions within this document were correct at the time of going to print Cirrus Research plc reserves the right to make any changes necessary without notice in line with the policy of continuing product development and improvement No part of this publication may be duplicated reprinted stored in a data processing system or transmitted by electronic mechanical photographic or other means or recorded translated edited abridged or expanded without the prior written consent of Cirrus Research plc No liability is accepted for any inaccuracies or omissions in this manual although due care has been taken to ensure that is it complete and accurate as possible Accessories supplied by Cirrus Research plc have been designed for use with the instrumentation manufactured by Cirrus Research plc No responsibility is accepted for damage caused by the use of any other parts or accessories In order to take account of a policy of continual development Cirrus Research plc reserves the right to change any of the information contained in this publicati
16. EENEN R NER AA RR AAEL EE NET 8 Make Multiple Measurerments 2 er retro avian dees decay ye re or a O wwe ded Erase RM UAE Va e EE RE 8 QUICK cir TECH 8 Section 3 Using the CR 261S Sound Level Meter esee esee nnne nnn 11 Unpacking and checking the Sound Level Meter ecceeceee eee eee eee teeta eee eee mene 11 Batteries e PM CM eored chee en oo aetna the Eaa aa oie dahudnt oie a eerie MET 11 Windshield iecit a rr can pore cR I erar ag auue cas ERARA A ud ide ERRARE UE MEE KDE Ea EEE Da ADU TES QURE ATRA Dadi 12 Keypad Functiofs 2 eot iue iiee erhebt EOE MARE Ea I REC EI ID RD ERE redu TREE VELO IDE REG 13 Calibrating the Sound Level Meter eise enne nt n Ra ARR ad ka RR ERGRRERERERR SN PRAE E RRRRNR EAR RRRIRRERS 13 Changing the Calibration bevel 5 cere von edel v e np Mrs a A d pa mW Ra c e TE RD VR DAD EAN TE 14 Setting the measurement range cece eee Eee eee se seen mense 14 Setting the measurement modes ics eese deese dee b naked erba ea FRED CIR RT Lara ed aieo ents 15 Single Measurement Modea aietara nE esee essen eene heme sies nemen esee nene nnne 15 Multiple Measurement Mode with the Remote Control Cable ssssssssssrsssrrssrrssrrnnsrrnnrrrnernrnrrrrsrnnns 15 Switching off the instrument sssini ena ea aana AE sehen eme senses 16 Overload and nder Range reno Re acre Ra ach xe evs er a crx e beeen Rd 16 Section 4 Vehicle Noise Measurements e
17. Sound Level Meter must be positioned as follows Vertical In line with the exhaust but not less than 0 2m from the ground Horizontal 0 5m from the outlet of the exhaust at an angle of 45 10 The microphone must be placed on the outside edge of the vehicle The CT 4 Tripod supplied with the CK 261S Sound Level Meter Measurement kit will position the microphone capsule at a height of 0 2m from the ground CR 261S Vehicle Noise Sound Level Meter Page 19 The Positioning Template supplied with the CK 261S Vehicle Noise Measurement Kit will put the microphone at 0 5m and 45 from the exhaust The figures below show the positioning of the microphone in relation to the vehicle height of exhaust pipe centreline 0 2m min l l o 0 5m Page 20 CR 261S Vehicle Noise Sound Level Meter L lt 0 3m 0 3m e i q 0 2m min height of exhaust pipe centreline CR 261S Vehicle Noise Sound Level Meter Page 21 0 2m min height of exhaust pipe centreline ao x gt 0 3m 70 3 0 2m min height of exhaust pipe centreline C Page 22 CR 261S Vehicle Noise Sound Level Meter gt 0 5m For vehicles with two or more exhausts spaced not more than 0 3m apart and connected to a single silencer only one measurement position shall be used The microphone position shall be related to the exhaust outlet nearest to the out
18. Start up screen will be displayed and after a short time the display will change to show the last measurement that was made Ci p q IFrUS If there are no measurements in memory the instrument Research plc baila P will indicate that there are no measurements in the CR 261S 1 00 memory Calibrating the Sound Level Meter Turn the acoustic calibrator level on the Acoustic Calibrator Gently push the calibrator onto the microphone capsule slowly twisting clockwise ox Press the CAL button to start the calibration procedure Calibrating During the calibration the instrument will display the FIR wait calibration status 60 130 T Calibrated If the calibration is successful the instrument will display to 93 7 dBA the calibration level Press the Start button to begin a new measurement or to return to the main screen Reset to measure If the calibration is not successful the instrument will display an error message These are shown below Page 14 CR 261S Vehicle Noise Sound Level Meter 60 m 130 B Scape The calibration level is below the set level Check that the DAE Calibrator is switched on and that it is connected correctly to the Sound Level Meter Reset to measure 60 m S 130 B SPL Too high Not Calibrated The calibration level is above the set level Check that the Calibrator is set to the correct level Reset to measure 60m
19. e cha IA Rar Rr ro nia KONE De iM Sica ATEOA vines aces ENDA cas sates e EN EE ENS 31 MICGFOPNONG E 31 Microphone Preamplifier esssesseeseeeeeeenenn emen nnnm LEA AA nena nna sena sena seen 31 Extension cable S Air ove Ex er e ER NE DER ADAE ATA EAT DER eX iva te UR TE eats 31 Time Welghtiigs isoliert aet teaser eese rhe dius eie ERE RYE CARRIADR URLUNDREE REO am RR iaaa E ELIT Edda 31 Frequency Welightihngs nits eit ter d e deter t tete cea e ree aa idence ee a 31 Amplitude Weighting ansin tinna na RA RERUM eae ane eee REN ee eed oe ER ed RR RA TER a 31 Measurement Range terre ce Rer Le pate enr e pex and coher dawned ange cose aad dented EROR ERE aAa 31 Noise Floor Typical ien en etcetera n e ations mad TENE EA EAA A aV E bua Ka cR E 31 Available Measurements nae deletes iE RE RE D ccr a o XX e E RR ER ER EE REO C RO A ER CR 31 Page 4 CR 261S Vehicle Noise Sound Level Meter Single Measurement MOde oi uie etn rines se ne pesa etate vse egal nega cheated EERa aa YR NESA FERRE ERR obverse d 31 Multiple Measurement Mode 5 eee rese dnas uu ka a ata siege EE SEGRE esed ESA kan usua na ada Fake aa dd 32 Measurermient Storage ss esee tede e eese eue 32 IBI ry eae 32 ls 32 Dimensions ess educ ce isaac ass ex xe t x ls x ee x rx e d tea ix t ae este Rn dx UR X dx 32 ilf s 32 Battery MCN EE 32 Environmental tte eer ex rete texere Mick ree Ek EXER exe Td e
20. ement Mode with the Remote Control Cable In Multiple Measurement Mode the instrument displays the currnet Larmax and the last two Larmax S In this mode the instrument is controlled through a push button on a lead that connects to the bottom of the instrument When the ZL 261S Remote Control cable is plugged into the CR 261S Sound Level Meter the instrument will automatically switch to the Multiple Measurement Mode When first entering this mode there are no levels displayed untill the first measurement is taken When a fourth measurement is taken the very first measurement is removed and so forth When in this mode the cable does not effect any measurement perameters 130 M 60 130 B LAFmax dB LAFmax LAFmax LAFmax 05 0 dB dB Page 16 CR 261S Vehicle Noise Sound Level Meter Switching off the instrument Press and hold the Power Button to switch off the Sound Level Meter Overload and Under Range If the noise level is over the instruments displayed range the 60 ue Gi 130 E LAFmax dB instrument will display the Overload symbol If during a measurement the 69 H e JU H level is exceeded OL appears on the display this stays present until the measurement is reset If the noise level is below the instruments displayed range the instrument will display the Under Range symbol When the level is no longer below the display range the UR
21. ese esee sense e nnn nn unu nun ununi n nnn nnn nnn 17 OVetrVIeW A T T E vem vat Ro Du UR eeu ev Du Pe Ee bu Gale etc P D ew HE Dub UR ew IR OR RR ele 17 arcc 17 Background Noise and Wind Interference 0 cceee cece e eee eee eee eee emen esee enemies 18 Numbertr of Measurements exer e ie reni cc deen e panne case UAR UE DERE E E i UnA E AMEENAA KETE E EENE CRM EARUM 18 Microphone POSITION see ex rk xr eeu evan E Y EXER IK Re Er E RES 18 Section 5 Maintenance amp Care cce esseeeeee see ne annu nn annu n manna nana nuum nnna 24 Section 6 Troubleshooting eseeeeieieseeseseuseunu nena nuum ua uana nau uu sauna aeu usan ua anu annu 25 LII etm 25 Cali ratio ii misrasi EET 25 Measurerrents amp Settings tip E e pe ERE E EE re Er E SEEE ARRERA EENEN Ee 26 Section 7 Glossary eeseeieieeieieesesuuueuuuauunanau Rua a RR RR RR RR RR RR RR Ru Rau usada adu ada uada annua 27 Appendix 1 Rating Plate I nformation leseseesesseseesesea enn nu nna u nna unauunaannun 28 Appendix 2 Specifications eee eeeeeeeer eene nn enne h nenne hne u nana nahm u nana nuum n raura n nnn 31 Instr rment Verslols c ee a ERR EE REX ETUR e DRAN QR DATA US KR RR RR D S ER BORGO NE ERA URGE 31 Applicable Standards entere ber deter iR hec ere De Fee pad Rd SER I RIRT PER IDA TEODROS 31 Sound Eevel Meterz ur ie rre Ie r
22. his means that a signal with a crest factor of ten will produce an overload at 17dB below the expected top of the range selected The reading of this signal will be within the tolerances of IEC60651 up to the point where the overload occurs With A Frequency Weighting the linearity range exceeds 70dB The reference sound pressure is 1 Pa 94dB The frequency weighting characteristic for measurements is A weighting F response is fitted with a Maximum Hold on the max RMS value of each This parameter can be read in all modes An acceleration of 0 1g over the frequency range 63 4kHz results in a reading of less than 50dB on any axis or weighting 1 oersted produces a reading of less than 50dB on any weighting The units operate from 10 degree C to 50 degree C with a maximum reading change of 0 5dB but is typically less than 0 3dB We recommend that the operator should be at least 1m from the microphone during measurement The specification is met at temperatures from 10 to 50 degrees C The maximum deviation amounts to 0 5 dB typical 0 3 dB The unit will meet its specification at any humidity from 0 to 95 9o RH CR 261S Vehicle Noise Sound Level Meter Page 29 Maximum storage temperature of 60 degree 50 degree extended period and 50 RH should be observed Care should be taken when taking an instrument rapidly from sub zero temperatures to room temperature or above as condensation can take place inside the ins
23. instrument Slide the cover to the right hand side to remove and to access the battery holder BATTERY COVER s Ensure the instrument is switched off Remove the battery holder from the instrument and insert the batteries The CR 260 instruments uses two AA type batteries also known as LR6 1 Batteries 2 External Interface Socket Not Used 3 Remote Control Socket JAN Ensure that the batteries are inserted correctly DO NOT reverse the polarity A of the batteries as this may cause damage to the instrument Page 12 CR 261S Vehicle Noise Sound Level Meter Windshield The CR 261S can be used with a UA 237 Foam Windshield which will reduce the noise levels generated by air turbulence over the microphone capsule The windshield can also be used to protect the microphone capsule of the Sound Level Meter from dust and fluids which may affect the performance of the instrument To use the UA 237 Windshield push the hole in the windshield over the microphone of the Sound Level Meter The UA 237 Windshield must be removed before the Sound Level Meter can be calibrated CR 261S Vehicle Noise Sound Level Meter Page 13 Keypad Functions Measurement Mode Select the measurement mode amp view the current measurement mode settings Ca Press the CAL button to start the calibration procedure Press the Power Button to switch on the Sound Level Meter amp OO When the instrument is switched on the
24. is can cause severe damage to the membrane Physical damage to the microphone capsule is not covered by the instrument warranty To remove the microphone from the pre amp make sure you grasp it by the bottom section of the microphone not by the microphone grill To unscrew the microphone turn bay cla ro A X s If you experience any problems with the operation of the instrument refer to page 25 for basic troubleshooting If this does not solve the problem contact Cirrus Research plc or your local representative for further assistance CR 261S Vehicle Noise Sound Level Meter Section 6 Troubleshooting Page 25 This section contains information which may solve simple operational problems you may encounter If you are unable to solve the problem or experience any problems with the assembly or operation of the instrument contact Cirrus Research plc or your local representative for further assistance Basics Symptom Possible Cause Possible Remedy The instrument does not switch on The batteries are not fitted Fit new batteries and switch on The batteries are flat or very low Fit new batteries and switch on The batteries are not correctly fitted Remove the batteries and check the polarity of the batteries The instrument has become corrupted Contact your local distributor or Cirrus Research plc Calibration Symptom Possible Cause Possible Remedy
25. l CR 261S Directional Response 0 150deg Vertical Relative Response dB 100 1000 10000 100000 Frequency Hz 0V 10V 20V 30V 40V 50V 60V 70V 80V 90V 100V 110V 120V 130V 140V 150V Page Relative Response dB 40 CR 261S Vehicle Noise Sound Level Meter CR 261S Directional Response 0 150deg Vertical 100 1000 10000 100000 Frequency Hz 0 0V 10V 20V 30V 40V 50V 60V 70V 80V 90V Relative Response dB CR 261S Directional Response 0 150deg Vertical 100 1000 10000 100000 Frequency Hz 0 0V 10V 20V 30V Relative Response dB CR 261S Vehicle Noise Sound Level Meter Page 41 CR 261S Directional Response 0 150deg Vertical 100 1000 10000 100000 Frequency Hz 0H WS 10H WS 20H WS 30H WS 40H WS 50H WS 60H WS 70H WS 80H WS 90H WS 100H WS 110H WS 120H WS 130H WS 140H WS 150H WS Page 42 CR 261S Vehicle Noise Sound Level Meter Directional Sensitivity with UA 237 Windshield CR 261S Directi
26. led in a figure of eight configuration The calibration procedure and the correction data apply within 65 kPa to 108 kPa for static pressure 0 C to 50 C temperature 25 to 90 r H without dew points from 10 C to 39 C The version of the firmware is displayed when the Sound Level Meter is switched on NOTE Do not open the Sound Level Meter Damage can be caused by electrostatic discharge when opening the equipment Os 8 i B io s CR 261S Vehicle Noise Sound Level Meter Page 31 Appendix 2 Specifications Instrument Versions CR 261S Type 1 Applicable Standards Sound Level Meter IEC 61672 1 2002 Class 1 Group X Microphone Type 1 Class Type 1 pre polarized Free field 7 Condenser Nominal Sensitivity of 50mV Pa at 1000Hz Capacitance 18pF Microphone Preamplifier Type 1 MV 200C Integral Preamplifier Extension cables None Time Weightings FY Fast to IEC 61672 1 2002 Class 1 Group X The response time for Fast being 0 125s Frequency Weightings A A Weighting C C Weighting Amplitude Weighting Q 3 True Energy Integration Measurement Range 60dB A to 130dB A Class 1 60dB C to 130dB C Class 1 Noise Floor Typical 54dB A Class 1 54dB C Class 1 The noise floor of the instrument is 6dB below the bottom of the measurement range of the ins
27. on without prior notice Produced by Cirrus Research plc Acoustic House Bridlington Road Hunmanby North Yorkshire YO14 OPH United Kingdom Copyright Cirrus Research plc 2007 Reference Number 07 01 CR 2615S 01 Document Printing Date Friday 02 February 2007 CR 261S Vehicle Noise Sound Level Meter Page 3 Preface esie reete UisYee vetsseuaUs ec veRa eaa eeR aUa eni ERA We VENE ERR EE RSEN PRRURS A N eaea riS 5 Manual Contents acc aitaverdecsatiads ree ir ot cess toi Lee eL a tr EPA FER Sra e DER pe er eau E a OLI DENTS 5 Messages and Symbols er o x Ba Dede AA AEAEE E Aa ADE RAT E PRENMTARANRRRYT RR e KE 6 Section 1 I ntroduction ee eeeeeeeieeieeiree ea ne annu neun annu amu aman mauu nuam u umana umana n nnn 7 Maim Features se i ree e Rex Ox vie Rr eve cad eu ans en Ro ae Rn er Da rh 7 Measurement FUNCTIONS pase ecu cR Etpe v Codex e envy eater ense va ae uuu ea EVA CE Ebr ERN eU Ee eV Rare bik vx Eae Y 7 Single Measurement Mode ssssssssssssssssesse eene heme hne he esses see en es men sese eene 7 Multiple Measurement Mode ccsssssssseseeeee nennen nnne nnn nnne rehenes rehenes nnn 7 Options amp ACCESSOME S sss s eese b eere re Salts x E ea e PI DARSANA PEENE E dE e arE delve EP dx EFE E T Er EXE 7 Section 2 Getting Started i iii ausan anasa raped erara u aua aa uak usua usan uana annu 8 POW TOn LEE ELE 8 Make a Single Mode Measurement reines asas ausa nana fa gana ERE RE
28. onal Response 0 30deg Horizontal w ith Windshield Relative Response dB 4 T 100 1000 10000 100000 Frequency Hz OH WS 10H WS 20H WS 30H WS CR 261S Directional Response 0 90deg Horizontal with Windshield Relative Response dB 100 1000 10000 100000 Frequency Hz 0H WS 10H WS 20H WS 30H WS 40H WS 50H WS 60H WS 70H WS 80H WS 90H WS Relative Response dB CR 261S Directional Response 0 150deg Vertical with Windshield Page 43 CR 261S Vehicle Noise Sound Level Meter 100 1000 10000 Frequency Hz 0V WS 10V WS 20V WS 30V WS 40V4 WS 50V WS 60V WS 70V WS 80V WS 90V WS 100V WS 110V WS 120V WS 130V WS 140V WS 150V WS 100000 Page 44 CR 261S Vehicle Noise Sound Level Meter CR 2618 Direcitional Response 0 90deg Vertical with Windshield Relative Response dB 100 1000 10000 100000 Frequency Hz 0V WS 10V WS 20V WS 30V WS 40V WS 50V WS 60V WS 70V WS 80V WS 90V WS Relative Response dB 2 4
29. ontrol use is a 5m long encased co axial cable with a one touch start trigger switch Overload Levels The start point for all tests of the linear operating range is 94dB except the A weighted linearity at frequencies lower than 50Hz for which the level is 74dB Limits of the linear working areas dB Lig Lc 31 5 Hz from 60 from 60 to 92 to 128 1 kHz from 60 from 60 to 130 to 130 12 5 kHz from 60 from 60 to 126 to 124 A Weighting Overload levels lowest level at which the overload signal appears 31 5 93dB 1k 131dB 4k 131dB 8k 131dB 12k5 127dB C Weighting Overload levels lowest level at which the overload signal appears 31 5 129dB 1k 131dB 4k 131dB 8k 128dB CR 261S Vehicle Noise Sound Level Meter Page 35 12k5 125dB Note C Weighting is used for test purposes only Frequency weightings and Tolerances for A and C Weighting Nominal Frequency Weighting Tolerance Frequency ad eas Ome s d de 63 262 68 15 89 zs es ms 0 os o as 259 ee o 4 s 8 o va o 8 o 4 o eg Jis wea SS SS 80 os o i4 1000 e 05 E e o 0 4 4000 1 08 6 16 0 6 ss 33 5179 Page 36 CR 261S Vehicle Noise Sound Level Meter CR 261S Directional Sensitivity Note The reference position is pa
30. rallel to the long side of the sound level meter All indicated angles are based on the longitudinal axis of a perfectly horizontal positioned sound level meter The following diagrams display information relating to tolerance and measurement values The blue line shows the positive tolerance whereas the red line indicates the negative tolerance CR 261S Vehicle Noise Sound Level Meter Page 37 Horizontal Relative Response dB Relative Response dB CR 261S Directional Response 0 150deg Horizontal 4 00 2 00 0 00 2 00 4 00 6 00 8 00 10 00 12 00 14 00 100 1000 10000 100000 Frequency Hz 0H 10H 20H 30H 40H 50H 60H 70H 80H 90H 100H 110H 120H 130H 140H 150H CR 261S Direction Response 0 90deg Horizontal 4 00 2 00 0 00 2 00 4 00 6 00 8 00 10 00 100 1000 10000 100000 Frequency Hz 0H 10H 20H 30H 40H 50H 60H 70H 80H 90H Page 38 CR 261S Vehicle Noise Sound Level Meter CR 261S Directional Response 0 30deg Horizontal Relative Response dB 2 100 1000 10000 100000 Frequency Hz 0H 10H 20H 30H CR 261S Vehicle Noise Sound Level Meter Page 39 Vertica
31. side edge of the vehicle For vehicles with a vertical exhaust for example commercial vehicles the microphone shall be placed at a height of the exhaust outlet orientated upwards and with the vertical axis of the exhaust It shall be placed 0 5m from the side of the vehicle nearest to the outlet orifice CR 261S Vehicle Noise Sound Level Meter Page 23 For vehicles provided with exhaust outlets spaced more than 0 3m apart one measurement shall be made for each outlet as if it were the only one and the highest level noted Page 24 CR 261S Vehicle Noise Sound Level Meter Section 5 Maintenance amp Care The CR 261S is a precision measurement instrument and should be treated with care Do not allow the instrument to be exposed to substances which may cause damage to the components of the unit If the instrument is to be used in an environment where particles such as dust may come into contact with the instrument always use a Windshield UA 237 to protect the microphone capsule The instrument is not waterproof and should not be used in situations where moisture will form or condense on the microphone capsule or the instrument body If the instrument becomes dusty wipe it down with a cloth that is lightly dampened with water or a mild detergent Do not use aromatic hydrocarbons chlorinated solvents or methanol based fluids when wiping down the meter YN Do not clean the microphone capsule Do not remove the microphone grill as A th
32. t accident damage The guarantee requires the user to return the unit to their nearest authorised Cirrus Research plc Agent This guarantee is in addition to any statutory rights in your country Cirrus Research Offices The addresses given below are the Cirrus Research plc offices Cirrus Research plc also have approved distributors and agents is many countries worldwide For details of your local representative please contact Cirrus Research plc at the address below Contact details for Cirrus Research authorised distributors and agents are also available from the Internet Web site at the address shown below Main Office Cirrus Research plc Acoustic House Bridlington Road Hunmanby North Yorkshire United Kingdom YO14 OPH Telephone 01723 891655 Fax 01723 891742 e mail sales cirrusresearch co uk Technical Support support cirrusresearch co uk Web Site www cirrusresearch co uk Germany Cirrus Research Buro Dresden Schlueterstrasse 29 01277 Dresden Germany Telephone 49 351 316 0950 Fax 49 351 316 0949 e mail vertieb cirrusresearch de Website www cirrusresearch de
33. the exhaust noise is measured Any obstacles outside the test site shall not be closer than 3m to the microphone during the test With the exception of the observer and the driver no person whose presence influences the meter readings shall remain in the test site during the test The measurements shall not be made in adverse weather conditions Gusts of wind shall not affect the measurements It is recommended that tests should not be made in wind speeds at microphone height that exceed 5 m s The figures below show the recommended distances of the test areas for cars and motorcycles Page 18 CR 261S Vehicle Noise Sound Level Meter Background Noise and Wind Interference The level of background noise including any wind at each measurement position shall be at least 10dB less than the levels measured during the tests Number of Measurements At least three measurements shall be carried out at each measuring position The measurements shall be considered to be valid if the range of three measurements made immediately one after the other is not greater than 2dB The arithmetic mean given by these three measurements shall constitute the results Microphone Position When the noise measurements are to be made close to the exhaust of the vehicle which is the common location of most measurements of this type the positioning of the microphone is important The microphone capsule of the instrument not the body of the
34. ting Acoustic Calibrator Broadband CE Marking dB A Decibel dB Fast Time Weighting IEC 61672 1 2003 Lar LaFmax Ler Lcrmax Overload Sound Level Sound Level Meter SPL Class 1 Classs 2 Under Range CR 261S Vehicle Noise Sound Level Meter Page 27 A standard weighting of the audible frequencies designed to reflect the response of the human ear to noise An instrument that provides a reference noise source that is used to calibrate and check the performance of a Sound Level Meter Noise Measurements using parameters which include all the audible noise such as dB A and dB C A label used to show that the Sound Level Meter conforms to the specification of a European Directive Decibels A weighted The units of sound level and noise exposure measurement A standard time weighting applied by the Sound Level Meter The International standard for Sound Level Meter and Integrating Averaging Sound Level Meters that replaces both IEC 60651 and IEC 60804 Sound level with A Frequency weighting and Fast Time weighting The maximum Sound level with A Frequency weighting and Fast Time weighting Sound level with C Frequency weighting and Fast Time weighting The maximum Sound level with C Frequency weighting and Fast Time weighting The input to the Sound Level Meter is too high for the current measurement range Change the range Sound Pressure Level with a Frequency weighting such as dB A
35. trument Available Measurements Single Measurement Mode Lar Sound Level Not Stored dB A Fast Time Weighting Page 32 CR 261S Vehicle Noise Sound Level Meter Larmax Maximum Sound Level dB A Fast Time Weighting Lcr Sound Level Not Stored dB C Fast Time Weighting Lcrmax Maximum Sound Level dB C Fast Time Weighting Measurement Duration Multiple Measurement Mode Larmax Maximum Sound Level dB A Fast Time Weighting Measurement Duration Measurement Storage No measurement data is stored Display Graphical LCD with Quasi Analogue Display Selected measurement parameter with level Warnings for Overload Under Range Battery Level Time amp Frequency Weighting Elapsed measurement time Measurement Range Refresh rate of twice per second Weight 450 gms Dimensions 340mm x 75mm x 25mm Batteries 2 x 1 5v Alkaline LR6 AA Battery Life Typically gt 12 hours Battery voltage is continuously monitored and warning is given on display of impending low battery condition When batteries approach end of life the unit will store any data required and switch off automatically Environmental Temperature Operating 10 C to 50 C Storage 20 C to 60 C Humidity Up to 95 RH Non Condensing CR 261S Vehicle Noise Sound Level Meter Page 33 Influence of Mechanical Vibration For mechanical vibrations with an acceleration of 1m s perpendicular to the level of the microphone membrane for the frequencies
36. trument and temporarily affect accuracy No long term damage should take place however The UA 237 Windshield has a small effect upon the measurement Between 1kHz and 10kHz this is less than O 5dB Please refer to page 46 for details The use of a pistonphone PF 101C is recommended to ensure long term compliance but for general short term compliance the CR 511F is used They should be returned to the factory annually to be checked against a secondary or transfer standard Any corrections specified in the calibrator or pistonphone manual should be applied for temperature or barometric pressure variation The observer should be behind the case for optimum results The operator should ever be at the side or in front of the unit When using cables which are not supplied by Cirrus Research plc the performance of the instrument cannot be guranteed The reference frequency used for calibration is 1kHz The reference range is 60dB to 130dB The warm up period is less than 10 secs although it is recommended that the unit should be switched on for at least one minute before calibration to provide optimum accuracy Never attempt calibration of an instrument that has not stabilised in temperature with its surroundings if you are seeking accurate results The settling time before valid Leq readings of constant signals are within 0 5dB of their final reading is 10secs and within 0 1dB within 1minute The battery life is greater than 12 hours with
37. w of the CR 261S Sound Level Meter features and capabilities Section 2 Getting Started provides a quick overview of how to begin using the instrument and how to carry out the basic measurements Section 3 Using the CR 261S describes the operation of the instrument Section 5 Maintenance amp Care describes the procedure that should be followed to ensure the instrument operates as efficiently as possible including changing batteries Section 6 Troubleshooting provides helpful information on how to perform some simple checks and suggests courses of action if the CR 261S Sound Level Meter does not seem to be working properly The Glossary defines general Acoustic terminology and includes a list of acronyms and abbreviations used in this manual The appendices contain technical information and specifications for the CR 261S Sound Level Meter Page 6 CR 261S Vehicle Noise Sound Level Meter Messages and Symbols Messages are used in this manual to bring important information to your attention The different message types are indicated as shown below failure to follow instructions may cause data loss or may damage the Pay attention A caution informs you that improper use of the equipment or A equipment Please read A note is a hint or advice that helps you make best use of the equipment and accessories CR 261S Vehicle Noise Sound Level Meter Page 7 Section 1 Introduction Main Features Measurement Functions The
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