Cirrus Research CR308, CR310 Handbook

Instrument Handbook

CR308/310 Sound Level Meters

The contents of this manual, including any illustrations, technical informaiton and descriptions, were correct at the time of printing. 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 it is complete and as 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.

Version 1.1 cr308-310/rev2/1018/en

CR:308 & CR:310 sound level meters - instrument handbook

Contents

1. Overview

2. First time use

3. Instrument features

4. Display interface

5. Keypad interface

6. Instrument operation

6.1 Selecting the frequency and time weighting

6.2 Maximum, minimum and LCpk values

6.3 Setting the level alarm (CR:308)

6.4 Performing and printing a measurement (CR:310)

7. Calibrating the meter

8. Speciﬁcation and technical information

9. Reference information for periodic testing

10. Options and accessories

11. Serial connection

12. Appendix A - CE Declaration of Conformity

13. Appendix B - Warranty information

14. Cirrus Research oces

4 4 5 8 10 11 11 11 12 13 14 15 17 20 21 22 23 26

CR:308 & CR:310 sound level meters - instrument handbook

1. Overview

Welcome to your new CR:308/310 series sound level meter. You’ve taken a great step towards protecting people’s hearing and this entry level meter will make it quick and easy for you to take simple noise measurements, providing you with the basic data you need.

The CR:308 is a general purpose digital sound level meter, designed to IEC 61672 to Class 2. The instrument has ‘F’ (fast) and ‘S’ (slow) time response and ‘A’ and ‘C’ frequency weightings. Additional features include max and min hold for the duration of the measurement, LCpk, and limit alarm, which you can set to indicate if the threshold you have set has been exceeded.

With the exception of the alarm indication, the CR:310 includes the features of the CR:308, with the addition of increased measurement capability, including integrating averaging, and the ability to print results directly from the meter.

CR:308 & CR:310 sound level meters - instrument handbook

Microphone

2. First time use

Before using your meter for the ﬁrst time, please check the contents of your instrument’s case, which should include the following:

• Sound level meter and Class 2 microphone

• Windshield

• 2 x AA batteries

Before starting a measurement, remove the black microphone protective cap (if ﬁtted) and where necessary, place the windshield carefully over the end of the microphone capsule.

Backlit display

Control keypad

Model number

Connectors

CR:308 & CR:310 sound level meters - instrument handbook

Tripod mount

Serial number label

AC/DC out

Serial connector for printer*

USB power input

*Printer functionality only available on the CR:310 model.

Battery compartment

CR:308 & CR:310 sound level meters - instrument handbook

4. Display interface

CR:308 & CR:310 sound level meters - instrument handbook

CR:308 & CR:310 main display

Under-range indicator

Measurement type

Battery level

Calibration display (press the CAL button) - see page 14

Alarm indicator (CR:308 only)

Measurement indicator

Overload indicator

Measurement

Calibrator level

Correction to be applied

CR:308 alarm set display (press ) - see page 12

Threshold level set

Alarm level enabled/disabled

CR:310 measurement display - see page 13

Overall measurement value

Under-range/ overload indicator

Current measured level

Measurement duration

CR:308 & CR:310 sound level meters - instrument handbook

5. Keypad interface

CR:308 keypad

Set alarm

Perform calibration

Softkey: CAL/OK

Fast/Slow toggle

Reset max/min

A or C weighting toggle

Calibration display (press the CAL button) - see page 14

CR:310 keypad

As per the CR:308 (above) with the following dierences.

Measurement start/stop

Perform calibration

Softkey: CAL/Print

Power on/o

Softkey: Exit

Select measurement view

6. Instrument operation

Fit new batteries by sliding the battery cover open and inserting two AA batteries in the correct orientation.

Switch on and allow the instrument to settle for 60 seconds before calibrating.

Before starting a measurement, calibrate the instrument as per the guidance in Chapter 7 of this handbook.

6.1 Selecting the frequency and time weighting

Select the measurement frequency and time weighting required:

To toggle between A and C weighting, press

To toggle between fast and slow weighting, press

The measurement type is displayed in the main window:

LAF - A frequency weighting and fast time weighting LCF - C frequency weighting and fast time weighting LAS - A frequency weighting and slow time weighting LCS - C frequency weighting and slow time weighting

To toggle the measurement values, press

measurement values if the meter is set to LAF:

LAF > LAFMax > LAFMin > LCpk > LAF

Integrating averaging measurements Lxeq1s and Lxeq8h are available for measurements on the CR:310 instrument.

. This will toggle through the following

6.2 Maximum, minimum and LCpk values

Maximum, minimum and LCpk values are shown for the duration of time since the meter was switched on, or since the reset button was last pressed.

These values can be reset by pressing

6.3 Setting the level alarm (CR:308)

CR:308 & CR:310 sound level meters - instrument handbook

6.4 Performing and printing a measurement (CR:310)

CR:308 & CR:310 sound level meters - instrument handbook

The level alarm function can be used to trigger an alert if the noise level exceeds a predetermined value, which is set by you.

To set the alarm level, press to enter the alarm set up display.

Set the desired level using the arrow buttons and enable the alarm using the arrow buttons to select the tick (a cross denotes that the level alarm is disabled). When set, press (OK).

NB: the alarm level must be set to less than 129dB.

With the alarm level enabled, the main display will show if the level has been exceeded by showing an Asterix (*) next to the sound level reading. The triggered threshold limit

can be reset by pressing .

Press to start or stop a measurement. Whilst a measurement is running, the latest values will be displayed on the screen, with the measurement duration shown at the bottom. Alternative measurement parameters can be viewed by pressing the up/down arrow buttons.

Overload and under-range are denoted by the ^ and indicators in the top right corner of the screen.

After stopping a measurement, the overall measurement values are displayed. Press the up/down arrows to scroll through the overall measurement values.

NB: this will also reset the maximum, minimum ad LCpk measurement.

If a printer is attached, the results can be printed by pressing (Print).

The measurement view can be canclled by pressing (Exit).

CR:308 & CR:310 sound level meters - instrument handbook

7 Calibrating the meter

Before making a measurement, it is important that you calibrate your instrument with an acoustic calibrator, such as the Cirrus Research CR:514 1kHz 94dB calibrator.

To start the process of calibration, ensure the microphone is ﬁtted correctly and place the acoustic calibrator over the microphone.

Press to enter the calibration menu.

Use the arrow keys to set the CAL LEVEL to the acoustic calibration level (94.0dB for the CR:514 calibrator).

Use the arrow keys to set the CORRECT value to 0.2dB, which will make the adjustment for the gap between the calibrator and the microphone (pressure ﬁeld of the acoustic calibrator and the free ﬁeld of the instrument and microphone) (for HY205 microphone). This will result in the meter reading 93.8dB when a 94dB calibrator is used.

Switch on the acoustic calibrator and press to automatically calibrate the meter.

Press to exit from the calibration display and to return back to the main display.

8 Speciﬁcation and technical information

Standards: IEC 61672-1:2013 Class 2

Measurement range: 30dB (A)~130dB (A) 40dB (C)~130dB (C)

Frequency weighting: A and C

Time weighting: Fast (F) and Slow (S)

Display functions: Normal, Maximum, Minimum, C peak

Measurement functions: LAF, LAS, LCF, LCS, LCpk

Noise ﬂoor < 25dB (A) and 35dB (C)

Display ﬂags: Alarm Limit, Overload, Under-range

Auto calibration range: ±4.5dB

Reference point: 94dB (1kHz), 92.9dB (8kHz)

Settling time: 60s

Display: Backlit 128×64 LCD

Resolution: 0.1dB

Electrical inputs: 5V power in via mini USB

Power: 2 x AA/LR6 1.5V batteries or 5V DC via Mini USB input

Battery life: 24 hours with alkaline batteries

Microphone: ½” pre-polarised electret condenser type HY:205

Operating temperature: 0°C to +40°C

Operating humidity: 25%~90%

Atmospheric pressure: 65kPa~108kPa

Storage Temperature: -20°C to +60°C

CR:308 & CR:310 sound level meters - instrument handbook

9 Reference Information for Periodic Testing

Dimensions: 215mm×68mm×32 mm

Weight: 220g (including battery)

Electrical Outputs: AC (tip 3.5mm jack) and DC (middle

3.5mm jack)

DC Output: voltage 15mV/dB, range 450mV~1950mV

AC Output: RMS 2V

Reference level (1kHz) 94dB

Reference level (8kHz) 92.9dB (A)

Linear range 8kHz 30-130dB

Linear range 4kHz 30-130dB

Linear range 1kHz 30-130dB

LCPeak maximum (500Hz, 1kHz, 8kHz) 133dB

Self-generated noise ﬂoor A weight = 25dB C weight = 35dB

Self-generated noise ﬂoor with mic ﬁtted A weight = 25dB C weight = 35dB

Dummy microphone capacitance 18pf

Recommended dummy microphone KP:66

Multifrequency acoustic calibrator correction data (set to pressure and test on A weighting)

Frequency Correction

125Hz 0.0

1kHz 0.2

8kHz 2.6

Free ﬁeld correction for HY205 microphone.

CR:308 & CR:310 sound level meters - instrument handbook

Directionality plots and case reﬂection plots

CR:308 & CR:310 sound level meters - instrument handbook

Frequency / kHz Free ﬁeld

correction / dB

1 0.1 6.3 1.7

1.25 0.1 8 2.6

1.6 0.2 10 4.4

2 0.3 12.5 5.3

2.5 0.5 16 6.5

3.15 0.7 18 7. 1

4 1.0 20 7.8

5 1.4 --- ---

Case reﬂection and windshield attenuation data.

Frequency / kHz Case correction Windshield

63 0 0 0.27

125 0 0 0.27

250 0.13 0.05 0.27

500 0.18 0.08 0.27

1000 0.09 0.1 0.27

2000 -0.16 0.26 0.27

4000 0.01 0.53 0.32

8000 -0.10 0.26 0.30

16000 -0.17 -0.58 0.29

Frequency / kHz Free ﬁeld

correction / dB

Uncertainty

correction

Add the above data to your measurement to correct.

CR:308 & CR:310 sound level meters - instrument handbook

10 Options and accessories

The following table contains information about the model options and accessories available with this sound level meter.

Cirrus part number Description

CR:308 Basic sound level meter with threshold

CR:310 Basic sound level meter with

measurement

PR:310 Thermal printer (for CR:310 only)

CR:514 Acoustic calibrator

CK:380 Kit case (empty)

CK:381 CR:308 kit including case, meter and

calibration

CK:382 CR:310 kit including case, meter and

calibrator

UA:30X Spare windshield

CP:65 Carrying pouch (sound level meter and

calibrator)

11 Serial connection

DB9, RS232 communication rate at 9600 Baud.

1 bit start, 8 bits data, 1 bit stop, No parity

CR:308 & CR:310 sound level meters - instrument handbook

12 Appendix A - CE Declaration of Conformity

Manufacturer:

Cirrus Research plc Acoustic House Bridlington Road, Hunmanby North Yorkshire YO14 0PH

Telephone: 01723 891655

Equipment manufactured after June 2018.

Equipment description

CR:308 sound level meter CR:310 sound level meter

Along with their standard accessories.

According to:

EMC Directive 2014/30/EU Low Voltage Directive 2014/35/EU

13 Appendix B - Warranty Information

1. 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:

Products manufactured by Cirrus Research plc

Repairs 3 months

Replacement microphone capsules 12 months

Spare parts (excluding replacement microphone capsules)

Products manufactured by a third party (see clauses 12 & 14 below)

2. The initial guarantee covers all faults and accidental damage to the product.

3. 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.

24 months

3 months

Based on the individual manufacturer’s warranty

Signed June 2018

Martin Williams Director

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 eectively 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.

4. 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 oer can only be redeemed once during the life of the instrument.

5. The initial guarantee, and any extended warranty is not transferrable and is provided to the original customer only.

6. Where a product is returned for routine veriﬁcation or calibration, the customer is responsible for all transportation, duty and other charges.

7. 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.

8. The customer must notify Cirrus Research plc in writing of any claimed defect in the product immediately upon discovering it.

9. 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.

10. 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

11. 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

CR:308 & CR:310 sound level meters - instrument handbook

14. No warranty is oered for used equipment unless a special arrangement is made and is conﬁrmed in writing by Cirrus Research plc

15. 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 aect the legal rights of the buyer and is in additional to any statutory rights.

CR:308 & CR:310 sound level meters - instrument handbook

12. 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.

13. 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.

CR:308 & CR:310 sound level meters - instrument handbook

14 Cirrus Research oces

The addresses given below are the Cirrus Research plc oces. Cirrus Research plc also have approved distributors and agents in many countries worldwide. For details of your local representative, please contact Cirrus Research plc using the information below. Contact details for Cirrus Research authorised distributors and agents are also available from the website at the address shown below.

Head Oce

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

Telephone: 0845 230 2434 +44 (0)1723 891655 Fax: +44 (0)1723 891742

Email: sales@cirrusresearch.com Website: www.cirrusresearch.co.uk

Cirrus Germany

Cirrus Research plc Deutschland Arabella Center Lyoner Strasse 44 – 48 D-60528 Frankfurt Germany

Telephone: +49 (0)69 95932047 Fax: +49 (0)69 95932049 Email: vertrieb@cirrusresearch.de Website: www.cirrusresearch.de

Cirrus France Ltd

679 avenue de la République 59800 Lille France

Telephone: 0 805 111 570 Email: sales@cirrusresearch.fr Web: www.cirrusresearch.fr

Cirrus Environmental

Unit 2 Bridlington Road Industrial Estate Hunmanby North Yorkshire YO14 0PH United Kingdom

Telephone: +44 (0) 1723 891722 Email: sales@cirrus-environmental. com Website: www.cirrus-environmental.com

Cirrus Spain

Av. Diagonal 468, 6° 08006 Barcelona España

Telephone: +34 933 622 89 Email: infos@cirrusresearch.es Website: www.cirrusresearch.es

cr308-310/rev2/1018/en

www.cirrusresearch.co.uk

sales@cirrusresearch.co.uk

Cirrus Research CR308, CR310 Handbook

Specifications and Main Features

Frequently Asked Questions

User Manual