CIRRUS CR 514 Acoustic Calibrator User Manual

: June 3, 2024
: Cirrus

Table of Contents

CIRRUS CR 514 Acoustic Calibrator
INTRODUCTION
Operation
Changing the Battery
Specification
Technical Information
Free Field Correction
EU Declaration of Conformity
Type Approval Certification
Product Guarantee & Extended Warranty
Cirrus Research Offices
References
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CIRRUS CR 514 Acoustic Calibrator

INTRODUCTION

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 publication without prior notice. Produced by Cirrus Research plc, Acoustic House, Bridlington Road, Hunmanby, North Yorkshire, YO14 0PH, United Kingdom.

Operation

Switching on the Calibrator
Press the aPower 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.

Permanent-on Mode
For some applications there may be a need to have the calibrator switched on continuously. To allow for this, the calibrator can be turned on by pressing and holding the power button for three seconds. Release the button and the indicator will flash to show that the unit is in permanent-on mode. Press the power button to switch off the calibrator.

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. Most modern Sound Level Meters have electronic calibration with the level adjusted automatically. Adjust the Sound Level Meter to the correct level where applicable. When correcting the value generated by the calibrator a correction for the type of microphone capsule may need to be applied (see Appendix 2)

Background Noise
In order for the calibrator to operate as intended, the ambient acoustic noise level should be no greater than 80dBA.

Stabilisation
In order for the sound pressure level and frequency to stabilise after switching the calibrator on when coupled to a microphone, a period of at least 30 seconds should be allowed before performing a calibration.

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.

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. Ensure that the battery is inserted with the correct polarity with the negative terminal at the contact with the larger cutout.

CIRRUS-CR-514-Acoustic-Calibrator-2

Battery type.
The battery should be an alkaline battery, not an ordinary dry cell. The battery is 9 volts when new and will operate the calibrator down to 6.4 volts. When the battery voltage is below 6.6 volts but above 6.4 volts, the power LED will flash to indicate that the battery voltage is low. When the battery voltage is below 6.4 volts the calibrator will not turn on. A discharged battery may allow switch-on but will soon drop in voltage and indicate low battery or switch off.

Specification

Frequency 1kHz ± 1%
Sound Level 94dB re 20μPa
Standardization
- 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 Diamete r 0.525 inch
Battery 1 x 9v 6F22 (Neda 1604)
Battery Life Approx 15 Hours Continuous Use
Battery Voltage 9v Nominal (10v Maximum, 6.4v Minimum)
Weight with Battery 185g
Dimensions 135mm x Ø48mm

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.
The calibrator conforms to IEC 60942:2003 for a modulated root-mean-square electromagnetic field strength of 10 V/m.
The maximum susceptibility to power and radio frequency fields is with the cavity facing away from the emitter with the battery compartment facing the table, the antenna polarisation horizontal and the calibrator switched on.

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).
The table below shows the correction values for the standard microphones of Cirrus Research plc.
Calibration corrections are listed below for the Cirrus Research plc ½” Capsules and three microphone capsules commonly used in Calibration Laboratories:

Microphone Correction Values:

CIRRUS-CR-514-Acoustic-Calibrator-3

Example
An example of the procedure used to calculate the value for an MK:224 microphone is shown below :

Level = 94.0dB + Microphone Correction
Level = 94.0dB + ( -0.3dB)
Level = 93.7dB

Different microphones will have different correction values. Please check the operation manual for the Sound Level Meter or microphone concerned for details.

EU Declaration of Conformity

Manufacturer:
Cirrus Research plc
Acoustic House, Bridlington Road
Hunmanby, North Yorkshire, YO14 0PH United Kingdom

Equipment Description

The following equipment manufactured after 1st January 2017:

CR:514 Acoustic Calibrator
CR:515 Acoustic Calibrator

Along with standard accessories

According to:

EMC Directive 2014/30/EU
Low Voltage Directive 2014/35/EU
RoHS Directive 2011/65/EU

meet the following standards

EN 61000-6-3:2007+A1:2011
Electromagnetic compatibility (EMC). Generic standards. Emission standard for residential, commercial and light-industrial environments
EN 61000-6-1:2007
Electromagnetic compatibility (EMC). Generic standards. Immunity for residential, commercial and light-industrial environments

Type Approval Certification

CIRRUS-CR-514-Acoustic-Calibrator-4

Product Guarantee & Extended Warranty

The period of the initial guarantee starts from the date of purchase, as a new instrument, from Cirrus Research plc or their formally approved distributors. The periods are as follows unless otherwise stated by Cirrus Research plc in writing:

The initial guarantee covers all faults and accidental damage to the product.
Warranty extension
If the product is returned to Cirrus Research plc or one of its Authorised Service & Calibration Centres for routine verification & calibration after the initial guarantee period, upon completion of the verification the product will be given an additional free one (1) year warranty. This must be done with a 6-week window of the anniversary date of shipment. This is limited to 3 weeks either side of the anniversary date of the shipment. It follows that if an instrument is routinely verified by Cirrus Research plc (or an Authorised Service & Calibration Centre) every year after the initial warranty period, the warranty is effectively continuous to a maximum of fifteen (15) years from the original date of purchase. There will be a charge for the verification (or calibration) of the equipment.
Buying back into the warranty
Where the warranty has expired, the customer can buy back into the warranty scheme. This reactivates the warranty for a further 12 months and provides the same level of cover as for the initial period above. This must be purchased at the same time as a calibration or verification. The maximum period of any warranty, whether it had been extended or not, is 15 years from the original purchase date. This offer can only be redeemed once during the life of the instrument.
The initial guarantee, and any extended warranty is not transferrable and is provided to the original customer only.
Where a product is returned for routine verification or calibration, the customer is responsible for all transportation, duty and other charges.
The user shall be responsible for determining if the product is suitable for the use and that such use complies with any applicable laws, regulations or standards.
The customer must notify Cirrus Research plc in writing of any claimed defect in the product immediately upon discovering it.
Where an instrument is being returned under the guarantee or warranty, it must be returned to Cirrus Research plc without undue delay at the customer’s risk with transportation charges prepaid.
Where the product is deemed to be faulty due to manufacturing defects, Cirrus Research plc shall:
- a. Repair or replace the defective products
- b. Be given reasonable time by the customer to make such repairs or replacements
- c. Return the product to the customer at Cirrus Research plc’s expense
Cirrus Research plc reserves the right to decline an instrument under the initial guarantee or extended warranty where;
- a. The product has continued to be used after defect has been discovered
- b. There is clear evidence of damage or misuse that is deemed to be more than minor accidental damage
- c. The product has been modified or repaired by persons other than those authorised by Cirrus Research plc
- d. The defect arises from the use of the product in conjunction with products or materials not reasonably contemplated by Cirrus Research plc
- e. No fault is found with the product
The initial guarantee or extended warranty does not extend to products or materials not supplied by or manufactured by Cirrus Research plc. Consumable items, including dry-cell and alkaline batteries are not covered by the initial guarantee or extended warranty.
Where re-chargeable batteries are used as an integral part of the product design and the product is shipped with the batteries installed (for example the doseBadge5 Noise Dosimeter), the standard product guarantee and extended warranty applies provided that the user has used the correct charging instructions and has followed the charging regime stated in the product manual.
No warranty is offered for used equipment unless a special arrangement is made and is confirmed in writing by Cirrus Research plc
Cirrus Research plc reserves the right to amend or update these terms and conditions without notice.

This warranty does not in any way reduce or affect the legal rights of the buyer and is in additional to any statutory rights.

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 0PH