CR:306 Sound Level Meter User Manual User Manual for the CR:306 Sound Level Meter This manual, the software to which it relates, the program code and drawings are all: © Copyright Cirrus Research plc 1989-2013 Page 1
Page 2 CR:306 Sound Level Meter User Manual 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.
CR:306 Sound Level Meter User Manual Page 3 Overview. ..................................................................................................................... 4 First time use. .............................................................................................................. 4 CR:306 Instrument Check List ...................................................................................... 4 Instrument Controls .....................................................................
Page 4 CR:306 Sound Level Meter User Manual Overview. Thank you for purchasing the CR:306 sound level meter from Cirrus Research plc. This entry level meter is designed to be quick and simple to use when taking basic sound measurements and we are sure it will meet your requirements. The CR:306 is a general purpose digital sound level meter which meets the full requirements of IEC 61672 to Class 2. The instrument has 'F' (Fast) response and has both 'A' and 'C' frequency weightings.
CR:306 Sound Level Meter User Manual Instrument Controls Page 5
Page 6 CR:306 Sound Level Meter User Manual
CR:306 Sound Level Meter User Manual Page 7 Taking Measurements Before taking measurements, ensure the instrument has a new or highly charged battery fitted. The instrument is supplied with a battery but it is not fitted for transit. See page 9 for details of fitting and changing the battery. Turn the instrument on by moving the OFF/F slide switch to the F position: > OFF >F = Instrument is powered off.
Page 8 CR:306 Sound Level Meter User Manual d) Wherever possible, always check the instrument calibration before and after each measurement. e) Whenever the instrument is not to be used for a long period of time (> one month) then remove the battery completely. This action will prevent leakage damage. Display and Indicators Display The LCD display of the CR:306 is scaled in decibels, either 'A' or 'C' weighted, depending on the position of the A/C slide switch.
CR:306 Sound Level Meter User Manual Page 9 Fitting a New Battery 1. Ensure the instrument is turned off before removing the battery cover. 2. Remove the battery cover. 3. The battery is made accessible by pressing the left hand side of the battery cover down slightly and then sliding it to the right. The spent battery can then be removed and disposed of safely. 4. A new battery, IEC 6F22 (NEDA 1604, PP3) can then be fitted. The battery can only be fitted in one orientation. 5.
Page 10 CR:306 Sound Level Meter User Manual Field Calibration It is vital that the calibration of ANY sound level meter is checked before and after each measurement. If this is done, it is reasonable to assume that the calibration during the measurement was correct. If this is NOT done, you will not subsequently be able to be certain that the instrument calibration was correct and you can never be certain the sound level was as measured. This process is commonly referred to as field calibration.
CR:306 Sound Level Meter User Manual Page 11 Technical Specification A full technical user manual, including mandated rating plate information is available upon request.
Page 12 CR:306 Sound Level Meter User Manual Appendix 1 - CE Declaration of Conformity Cirrus Research plc Hunmanby UK CE Certificate of Conformity Manufacturer: Cirrus Research plc Acoustic House, Bridlington Road Hunmanby, North Yorkshire, YO14 0PH United Kingdom Telephone +44 1723 891655 Equipment Description The following equipment manufactured after 1st January 2007: CR:306 Sound Level Meter CR:514 Acoustic Calibrator CR:515 Acoustic Calibrator Along with their standard accessories According to E
CR:306 Sound Level Meter User Manual Page 13 Appendix 2 Acoustic Calibrator Operation. Switching on the Calibrator Press the Power Button on the end of the Calibrator to switch the unit on. The Indicator will illuminate to show that the unit is operating. The calibrator will automatically switch off after 5 minutes to preserve battery power. To switch off the calibrator manually, press the power button again and the indicator will extinguish to show that the unit is switched off.
Page 14 CR:306 Sound Level Meter User Manual Calibrating a Sound Level Meter. Push the microphone of the Sound Level Meter into the cavity at the end of the calibrator. Ensure the microphone is fully inserted into the cavity and is past the ‘O’ ring seals. The microphone should be parallel to the body of the calibrator. Also ensure that the small bleed-hole next to the microphone cavity is not blocked as this could cause damage to the microphone.
CR:306 Sound Level Meter User Manual Page 15 Changing the Battery The CR:514 & CR:515 acoustic calibrators use a single 9v alkaline battery. This type of battery is known as 6F22 or NEDA 1604. It is also commonly known as PP3. 1. 2. Unscrew the screw holding the battery cover on, using a coin. The battery, type 6F22 (PP3) can now be eased out of its holder and replaced. The battery should be eased out terminal side first by pushing against the spring at the other end.
Page 16 CR:306 Sound Level Meter User Manual Specification. Frequency 1kHz ± 1% Sound Level 94dB re 20μPa Standardisation CR:514 - IEC 60942:2003 Class 2 CR:515 - IEC 60942:2003 Class 1 Distortion Less than 2% Operating Humidity 25 to 90% Relative Humidity Operating Static Pressure 65 kPa to 108kPa Operating Temperature -10oC to +50oC Storing Temperature -20oC to +60oC Effective Volume 6.19 cm3 ± 0.2 cm3 Cavity Diameter 0.
CR:306 Sound Level Meter User Manual Page 17 Technical Information The normal mode of operation of the calibrator is with the unit switched on. When the LED indicates the unit is switched on this produces the greatest radio frequency emissions. The calibrator continues to function after exposure to contact discharges up to 4kV and air discharges up to 8kV, for both positive and negative voltages relative to earth ground.
Page 18 CR:306 Sound Level Meter User Manual Free Field Correction When calibrating a microphone which is to be used for free field measurements, a small correction may be necessary to compensate for the difference between the microphone's free field response at 'zero degrees' or 'head-on' incidence and the pressure level generated by the calibrator. The correction is typically -0.3dB for ½ inch microphones (making the effective calibration level 93.7dB).
CR:306 Sound Level Meter User Manual Page 19 Warranty Information. 1. This document is a summary of the full warranty document and explains the Cirrus Research plc warranty in ordinary English; not in legal or complex terms. 2. The warranty covers any acoustic instrument such as a sound level meter, acoustic calibrator, real time acoustic analyser or personal sound exposure meter (dosemeter) manufactured by Cirrus Research plc after 1st September 2011. 3.
Page 20 CR:306 Sound Level Meter User Manual 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.
