Boggabri Coal Mine - Idemitsu · 2020. 4. 30. · 21328 CAT 785C APX01262 12/01/2016 1st gear forward 131 122 119. 3. Stock Standard N 21329 CAT 785C APX01263 12/01/2016 1st gear

Boggabri Coal Mine________________________________________

Mobile Plant Sound Power Survey

2016

Prepared for

Boggabri Coal Pty Limited

________________________________________

Boggabri Coal Mine - Mobile Plant Sound Power Survey 2016 Page i

Boggabri Coal Mine

Mobile Plant Sound Power Survey 2016

Reference: 15414_R01_Draft01

Report date: 26 February 2016

Prepared forBoggabri Coal Pty Limited

PO Box 12

Boggabri NSW 2382

Prepared byGlobal Acoustics Pty Ltd

PO Box 3115

Thornton NSW 2322

Prepared: Joel Curran

Chemical Engineer (Acoustics)

QA Review: Jeremy Welbourne

Civil Engineer (Acoustics)

Global Acoustics Pty Ltd ~ Environmental noise modelling and impact assessment ~ Sound power testing ~ Noise

control advice ~ Noise and vibration monitoring ~ OHS noise monitoring and advice ~ Expert evidence in Land and

Environment and Compensation Courts ~ Architectural acoustics ~ Blasting assessments and monitoring ~ Noise

management plans (NMP) ~ Sound level meter and noise logger sales and hire

Boggabri Coal Mine - Mobile Plant Sound Power Survey 2016 Page ii

Table of Contents

1 INTRODUCTION........................................................................................................................................................1

1.1 Terminology...........................................................................................................................................................1

2 METHODOLOGY........................................................................................................................................................2

2.1 Equipment Used....................................................................................................................................................4

2.2 Weather Conditions..............................................................................................................................................4

3 RESULTS........................................................................................................................................................................5

3.1 Criteria....................................................................................................................................................................5

3.2 Tonality...................................................................................................................................................................5

3.3 Overall Sound Power...........................................................................................................................................5

4 DISCUSSION..............................................................................................................................................................21

5 RECCOMENDATIONS.............................................................................................................................................22

Appendices

A CALIBRATION CERTIFICATES............................................................................................................................23

Boggabri Coal Mine - Mobile Plant Sound Power Survey 2016 Page 1

1 INTRODUCTION

This report provides sound power (LW) data for mobile equipment operating at Boggabri Coal Mine (BCM).

An assessment of tonality for each plant item is also provided.

Sound power level measurements in this report were taken between 11 January 2016 and 13 January 2016. A

total of 69 plant items were tested during this period.

1.1 Terminology

Some definitions of terminology, which may be used in this report, are provided in Table 1.1.

Table 1.1: TERMINOLOGY & ABBREVIATIONS

Descriptor Definition

dBDecibels. For sound pressure level this is 10 times the logarithm to the base 10 of the

ratio of the mean-square sound pressure to the square of the reference sound pressure (20micro-pascals)

dB(A)Noise level measurement units are decibels (dB). The “A” weighting scale is used to

describe human response to noise.

SPLSound pressure level (SPL), fluctuations in pressure measured as 10 times a logarithmic

scale, the reference pressure being 20 micro-pascals.

LWLinear sound power level, expressed in decibels, is the logarithmic ratio of the soundpower of a source in watts (W) relative to the sound power reference base of 10-12W

LWA A-weighted sound power level.

LAeq The average A-weighted noise energy during a measurement period, in dB


2 METHODOLOGY

Measurement and calculation was conducted using a reduced scope version of the following:

• AS 2012.1-1990 'Acoustics - Measurement of airborne noise emitted by earth-moving machinery and

agricultural tractors – Stationary test condition – Determination of Compliance With Limits for

External Noise';

• ISO 3744-2010 'Acoustics – Determination of sound power levels and sound energy levels of noise

sources using sound pressure – Engineering methods for an essentially free field over a reflecting

plane';

• ISO 6393:2008(E) 'Earth-moving machinery – Determination of sound power level – Stationary test

conditions'; and

• ISO 6395:2008(E) 'Earth-moving machinery – Determination of sound power level noise emissions –

Dynamic test conditions'.

The reduced scope uses fewer microphone positions than specified in the standards, with only ground

positions used. The rationale being to increase mobility of the testing team, provide flexibility in choice of

testing location, and to minimise disruption to mining production.

The test is mainly used as a screening tool. A more precise equipment sound power that would result from

full adherence to the above standards was not required. A minimum of two test runs were recorded for each

plant item with the aim to have less than 1.5 dB difference between results. It is considered that the results

are of sufficient accuracy and repeatability for the purpose of this survey.

Typical test areas showing microphone positions are presented in Figure 1 and Figure 2. The majority of

tests for mobile plant were undertaken using a dynamic test only, where the plant item passes through the

test area shown in Figure 1 under full power on level ground. The measurement is commenced and

completed when the plant item (centre of) passes between microphone positions 2 & 3 and 1&4 respectively.

Haul trucks, water carts, service carts, front end loaders, graders and dozers were all tested on a flat test area

at high idle using the test area shown in Figure 1. Drills were tested in-situ during normal operations using

the test area shown in Figure 2. Excavator testing involved measurement at one or more locations at a

known distance whilst normal truck loading operations were undertaken. This method provides the most

convenient means to test diggers as it presents minimal disruption to production. Excavator testing was

performed using some of the positions in Figure 2 (microphone positions being dependant on the excavator

immediate working environment. A more accurate and repeatable test would cause significant disruption to

production.

A more detailed test methodology document can be provided upon request.

hamish.russell

Note

remove bracket



2.1 Equipment Used

The equipment used to measure and record noise levels are listed in Table 2.1. Calibration certificates are

provided in Appendix A.

Table 2.1: SOUND LEVEL MEASUREMENT EQUIPMENT

Model Serial Number Calibration Due Date

SVAN 958 noise and vibration analyser 14216 19/03/2017

Rion NC74 sound level calibrator 50941314 18/11/2017

2.2 Weather Conditions

Weather conditions at the time of testing are presented in Table 2.2.

Table 2.2: ATMOSPHERIC CONDITIONS

Date Temperature (oC) Wind Speed (m/s) Barometric Pressure(hPa)

Relative Humidity (%)

11/01/2016 38 1 – 4 1015 38

12/01/2016 37 1 – 3 1015 37

13/01/2016 38 0 – 3 1017 11


3 RESULTS

3.1 Criteria

Sound power results for this report have been assessed against EA requirements as advised by Boggabri

Coal Mine. Dozers have been assessed against the mentioned limits for 1st gear tests only.

3.2 Tonality

The INP states that a noise is determined to be tonal when the level of an individual one-third octave band

exceeds the level of the adjacent bands on both sides by:

• 5 dB or more if the centre frequency of the band containing the tone is above 400Hz;

• 8 dB or more if the centre frequency of the band containing the tone is 160 Hz to 400 Hz inclusive;

• 15 dB or more if the centre frequency of the band containing the tone is below 160 Hz.

Tonal plant (Y/N) is listed in Table 3.1.

3.3 Overall Sound Power

Overall A-weighted sound power levels determined from measured SPL are shown in Table 3.1. Overall A-

weighted sound power results which exceeded the relevant criterion are presented in bold red type.

Single and one-third-octave graphs for equipment tested can be useful in identifying noise sources or

differences between like machines. These graphs have not been included in this report but are available

upon request.

Note that overall linear sound power levels are a better indicator of low frequency noise content of plant

than overall A-weighted sound power levels. Low frequency noise can propagate further than higher

frequency noise, and so can indicate items with higher potential for off-site noise impacts.

A comparison between sound power screening results from 2016 (Global Acoustics) and 2014 (another

consultant) is provided in Table 3.2.


Table 3.1: 2016 SOUND POWER LEVELS

Plant No. Make/Model Serial No. Test Date Test Type Result dB ResultdB(A)

LimitdB(A)

ExceedancedB(A)

Comments Tonal

Excavators/Loaders

22217 Hitachi EX3600 HCM18800L00000135 13/01/2016 Dynamic 126 119 120 Nil Stock Standard N

22249 CAT 6060/RH340FS

340106 NA NA Notoperating

Notoperating

120 NA NA NA

22255 CAT 6060/RH340 340133 12/01/2016 Dynamic 131 121 120 1 Stock Standard N

22256 CAT 6060/RH340 6060143 12/01/2016 Dynamic 128 122 120 2 Stock Standard N

22257 CAT 6030/RH120 120210 12/01/2016 Dynamic 125 119 120 Nil Stock Standard N

22266 LIE R9800 48013 12/01/2016 Dynamic 133 120 120 Nil Stock Standard N

22267 HIT ZX470 HCM1J200T00024717 NA NA InsignificantPlant

InsignificantPlant

120 NA NA NA

31298 HIT EX1900 HCM18K00J00001051 12/01/2016 Dynamic 125 115 120 Nil Stock Standard N

34278 HIT EX2600 HCMKBF90C0009001 13/01/2016 Dynamic 125 118 120 Nil Stock Standard N

34323 HIT MISC HCM1V100A00026670 NA NA InsignificantPlant

InsignificantPlant

120 NA NA NA

33449 CAT 998H BXY2723 NA NA InsignificantPlant

InsignificantPlant

117 NA NA NA

35137 CAT 993K Z9K00388 12/01/2016 Dynamic 125 117 117 Nil Stock Standard N

Caterpillar Trucks

380 CAT 785B 6HK00128 NA NA Idle plant Idle plant 119 NA NA NA



LimitdB(A)

ExceedancedB(A)

Comments Tonal






21327 CAT 785C APX01261 12/01/2016 1st gear forward 129 122 119 3 Stock Standard N




21551 CAT 789B 7EK00432 11/01/2016 1st gear forward 127 121 119 2 Stock Standard N


21553 CAT 789B 7EK00434 NA NA Idle plant Idle plant 119 NA NA NA






21571 CAT 789C 2BW01031 12/01/2016 1st gear forward 125 120 119 1 Stock Standard N



LimitdB(A)

ExceedancedB(A)

Comments Tonal

21593 CAT 789C 2BW01031 NA NA Notoperating

Notoperating

119 NA NA NA

Komatsu Trucks

21712 Komatsu 930E-4 A30986 11/01/2016 Forward 133 123 119 4 Stock Standard N










21723 Komatsu 930E-4 A31336 NA NA Notoperating

Notoperating

119 NA NA NA







LimitdB(A)

ExceedancedB(A)

Comments Tonal










Hitachi Trucks

31304 Hitachi EH3500 HCM8R800C00010178 12/01/2016 Forward 130 117 119 Nil Stock Standard N


31306 Hitachi EH3500 HCM8R800H00010175 12/01/2016 Forward 130 119 119 Nil Stock Standard N


33938 Hitachi EH3500 HCM8R00V00010060 11/01/2016 Forward 128 117 119 Nil Stock Standard N

Dozers

23779 CAT 85GG 0AMP00285 13/01/2016 NA Idle plant Idle plant 116 NA NA NA

33447 CAT 854K 22100367 13/01/2016 1st gear forward 121 117 116 1 Stock Standard N



LimitdB(A)

ExceedancedB(A)

Comments Tonal

23837 CAT D10T RJG01766 13/01/2016 1st gearforward/reverse

124/125 114/117 116 Nil/1 Stock Standard N

23868 CAT D10R 3KR01770 13/01/2016 NA Idle plant Idle plant 116 NA NA NA

23881 CAT D10R AKT00807 13/01/2016 NA Idle plant Idle plant 116 NA NA NA

23869 CAT D10R AKT00245 13/01/2016 NA Notoperating

Notoperating

116 NA NA NA




127/128 120/122 116 4/6 Stock Standard N


126/127 118/120 116 2/4 Stock Standard N


126/127 119/122 116 3/6 Stock Standard N

23902 CAT D11R 7PZ00902 13/01/2016 NA Idle plant Idle plant 116 NA NA NA

23905 CAT D11R AAF00135 13/01/2016 NA Idle plant Idle plant 116 NA NA NA

23922 CAT D11R 7PZ01382 13/01/2016 NA Idle plant Idle plant 116 NA NA NA

23925 CAT D11R 7PZ01663 13/01/2016 1st gearforward/reverse


23923 CAT D11R 7PZ01387 13/01/2016 1st gearforward/reverse

122/125 117/123 116 1/7 Stock Standard N

23918 CAT D11R 7PZ01241 13/01/2016 1st gear 122/125 117/122 116 1/6 Stock Standard N



LimitdB(A)

ExceedancedB(A)

Comments Tonal

forward/reverse

23926 CAT D11T GEB00223 13/01/2016 1st gearforward/reverse

126/127 120/122 116 4/6 Stock Standard N


126/129 119/120 116 3/4 Stock Standard N


126/128 118/122 116 2/6 Stock Standard N


128/129 122/124 116 6/8 Stock Standard N

Graders

22618 CAT 16H ATS00383 NA NA Notoperating

Notoperating

115 NA NA NA

22621 CAT 16H ATS00556 11/01/2016 1st gear forward 117 110 115 Nil Stock Standard N

33021 CAT 24M B9K00325 NA NA Notoperating

Notoperating

115 NA NA NA

33907 CAT 24M B9K419 NA NA Notoperating

Notoperating

115 NA NA NA

Service Trucks

21099 CAT 773D-ST 7ER00298 NA NA Notoperating

Notoperating

Nonespecified

NA NA NA

21299 CAT 773E-ST BDA01064 NA NA Notoperating

Notoperating

Nonespecified

NA NA NA



LimitdB(A)

ExceedancedB(A)

Comments Tonal

25648 ISU SERVICETRUCK

JALFSS90JE7000003 NA NA Notoperating

Notoperating

Nonespecified

NA NA NA

27649 MACK SERVICETRUCK METRO

6FME06D575D710827 NA NA Notoperating

Notoperating

Nonespecified

NA NA NA

27976 KEN LUBE TRUCK 6F500000BA444698 NA NA Notoperating

Notoperating

Nonespecified

NA NA NA

Water Trucks

270150 ISU WATERTRUCK

JALFVZ34SE7000040 NA NA Notoperating

Notoperating

117 NA NA NA

27482 MACK WATERTRUCK

6FME06D575D710827 NA NA Notoperating

Notoperating

117 NA NA NA

21017 CAT 775F-WT BDA00946 11/01/2016 1st gear forward 123 115 117 Nil Stock Standard N

21172 CAT 777C-WT 4XJ00701 NA NA Notoperating

Notoperating

117 NA NA NA

33749 CAT 777F-WT JRP02850 NA NA Notoperating

Notoperating

117 NA NA NA

35134 CAT 777F-WT JRP03165 11/01/2016 1st gear forward 122 116 117 Nil Stock Standard N

35135 CAT 777F-WT JRP00879 NA NA Idle plant Idle plant 117 NA NA NA

35136 CAT 777F-WT JRP02435 NA NA Notoperating

Notoperating

117 NA NA NA

Drills

850 REICHDRILL 750 34679 13/01/2016 Stationary 132 118 117 1 Stock Standard N



LimitdB(A)

ExceedancedB(A)

Comments Tonal

853 REICHDRILL 700 34748 13/01/2016 Stationary 128 114 117 Nil Stock Standard N


858 REICHDRILL 700 34695 13/01/2016 NA Notoperating

Notoperating

117 NA NA NA




Table 3.2: 2014 – 2016 SOUND POWER LEVEL COMPARISON

Plant No. Make/Model Serial No. 2014 Spectrum Result dB(A) 2016 GA Result dB(A) Change dB(A)

Excavators/Loaders

22217 Hitachi EX3600 HCM18800L00000135 117.7 119 1

22249 CAT 6060/RH340 FS 340106 120.9 Not operating NA

22255 CAT 6060/RH340 340133 Result not available 121 NA

22256 CAT 6060/RH340 6060143 120.7 122 1

22257 CAT 6030/RH120 120210 119.4 119 0

22266 LIE R9800 48013 118.2 120 2

22267 HIT ZX470 HCM1J200T00024717 107.1 Insignificant Plant NA

31298 HIT EX1900 HCM18K00J00001051 116 115 -1

34278 HIT EX2600 HCMKBF90C0009001 Not on-site 118 NA

34323 HIT MISC HCM1V100A00026670 Not on-site Insignificant Plant NA

33449 CAT 998H BXY2723 109.2 / 112.3 Insignificant Plant NA

35137 CAT 993K Z9K00388 Maintenance 117 NA

Caterpillar Trucks

380 CAT 785B 6HK00128 Idle plant Idle plant NA








21327 CAT 785C APX01261 Not operating 122 NA

21328 CAT 785C APX01262 119.6 122 2



21551 CAT 789B 7EK00432 118.2 121 3

21552 CAT 789B 7EK00433 119.2 121 2

21553 CAT 789B 7EK00434 Not operating Idle plant NA

21554 CAT 789B 7EK00456 118.7 121 2

21555 CAT 789B 7EK00457 118.8 121 2

21556 CAT 789B 7EK00509 119.4 121 2

21557 CAT 789B 7EK00610 119.6 121 1

21558 CAT 789B 7EK00611 118.9 121 2

21571 CAT 789C 2BW01031 119 120 1

21593 CAT 789C 2BW01031 Not on-site Not operating NA

Komatsu Trucks



21712 Komatsu 930E-4 A30986 119.9 123 3

21713 Komatsu 930E-4 A30987 119.2 124 5

21714 Komatsu 930E-4 A30988 119.6 122 2

21715 Komatsu 930E-4 A30995 118.9 123 4

21717 Komatsu 930E-4 A30997 119.2 123 4

21718 Komatsu 930E-4 A30998 119.2 123 4

21719 Komatsu 930E-4 A30999 118.9 122 3

21720 Komatsu 930E-4 A31271 119.3 122 3

21721 Komatsu 930E-4 A31303 120.2 124 4

21722 Komatsu 930E-4 A31305 119.6 124 4

21723 Komatsu 930E-4 A31336 118.9 Not operating NA

21724 Komatsu 930E-4 A31360 120 123 3

21725 Komatsu 930E-4 A31415 119.5 122 3

21747 Komatsu 930E-4 A31215 119.2 123 4

21748 Komatsu 930E-4 A31164 118.9 123 4

21749 Komatsu 930E-4 A31166 119.5 122 3

21750 Komatsu 930E-4 A31217 120.4 122 2

21751 Komatsu 930E-4 A31231 119.9 123 3



21752 Komatsu 930E-4 A31232 119.2 123 4

21753 Komatsu 930E-4 A31255 119.3 123 4

21754 Komatsu 930E-4 A31288 Not operating 123 NA

21755 Komatsu 930E-4 A31243 Not operating 123 NA

21756 Komatsu 930E-4 A31244 119.7 123 3

21757 Komatsu 930E-4 A31257 118.1 122 4

Hitachi Trucks

31304 Hitachi EH3500 HCM8R800C00010178 Not on-site 117 NA

31305 Hitachi EH3500 HCM8R800C00010177 Not on-site 117 NA

31306 Hitachi EH3500 HCM8R800H00010175 Not on-site 119 NA

31307 Hitachi EH3500 HCM8R800C00010132 113.5 117 4

33938 Hitachi EH3500 HCM8R00V00010060 114.1 117 3

Dozers

23779 CAT 85GG 0AMP00285 108.9/ 111.5 Idle plant NA

33447 CAT 854K 22100367 107.9 / 108.1 117 NA

23837 CAT D10T RJG01766 116.6 / 122.9 114/117 NA

23868 CAT D10R 3KR01770 116.5 / 123.5 Idle plant NA

23881 CAT D10R AKT00807 115.4 / 120.5 Idle plant NA



23869 CAT D10R AKT00245 Not on-site Not operating NA

33031 CAT D10T RJG02086 116.3 / 123.1 115/119 NA

34222 CAT D10T RJG01936 115.4 / 122.4 120/122 NA

23834 CAT D10T RJG01564 Not on-site 118/120 NA

23836 CAT D10T RJG01782 Not on-site 119/122 NA

23902 CAT D11R 7PZ00902 119.7 / 123.9 Idle plant NA

23905 CAT D11R AAF00135 Not operating Idle plant NA

23922 CAT D11R 7PZ01382 120.9 / 125.7 Idle plant NA

23925 CAT D11R 7PZ01663 114.0 / 118.1 116/119 NA

23923 CAT D11R 7PZ01387 Not on-site 117/123 NA

23918 CAT D11R 7PZ01241 Not on-site 117/122 NA

23926 CAT D11T GEB00223 117.6 / 124.4 120/122 NA

23928 CAT D11T GEB00251 118.8 / 125.5 119/120 NA

34438 CAT D11T GEB00362 116.3 / 122.6 118/122 NA

34439 CAT D11T GEB00351 116.6 / 122.9 122/124 NA

Graders

22618 CAT 16H ATS00383 Not operating Not operating NA

22621 CAT 16H ATS00556 Not operating 110 NA



33021 CAT 24M B9K00325 Not operating Not operating NA

33907 CAT 24M B9K419 108.8 Not operating NA

Service Trucks

21099 CAT 773D-ST 7ER00298 Not operating Not operating NA

21299 CAT 773E-ST BDA01064 Not operating Not operating NA

25648 ISU SERVICE TRUCK JALFSS90JE7000003 Not operating Not operating NA

27649 MACK SERVICE TRUCKMETRO

6FME06D575D710827 Not operating Not operating NA

27976 KEN LUBE TRUCK 6F500000BA444698 Not operating Not operating NA

Water Trucks

270150 ISU WATER TRUCK JALFVZ34SE7000040 Not operating Not operating NA

27482 MACK WATER TRUCK 6FME06D575D710827 Not operating Not operating NA

21017 CAT 775F-WT BDA00946 114.4 115 1

21172 CAT 777C-WT 4XJ00701 Not on-site Not operating NA

33749 CAT 777F-WT JRP02850 Not on-site Not operating NA

35134 CAT 777F-WT JRP03165 Result not available 116 NA

35135 CAT 777F-WT JRP00879 Not operating Idle plant NA

35136 CAT 777F-WT JRP02435 112.4 Not operating NA

Drills



850 REICHDRILL 750 34679 Not operating 118 NA

853 REICHDRILL 700 34748 111.9 114 2

855 REICHDRILL 700 34837 Not operating 116 NA

858 REICHDRILL 700 34695 Not on-site Not operating NA

861 REICHDRILL 700 610050 110.3 113 3

863 REICHDRILL 700 69614 111 112 1


4 DISCUSSION

Table 3.1 highlights:

• All CAT 785C haul trucks exceeded the relevant sound power limit by 3 dB or more;

• All Komatsu 930E haul trucks exceeded the relevant sound power limit by 3 dB or more; and

• The majority of dozers exceeded the relevant sound power limit during either the 1st gear forward or

reverse test.

Table 3.2 highlights:

• Truck 551 increased by 3 dB over 2014 sound power levels;

• The majority of Komatsu 930E trucks increased by 3 dB or more over 2014 sound power levels;

• Trucks 307 and 938 increased by 3 dB or more over 2014 sound power levels;

• Drill 861 increased by 3 dB over 2014 sound power levels; and

• No comparison has been made for dozers as 2014 results from another consultant were presented as

a combined forward/reverse cycle for 1st and 2nd gear, whilst Global Acoustic results are presented

as separate forward and reverse test results for 1st gear only.

Due to the uncertainty over test methodology differences between 2014 and 2016 sound power testing, the

above points of note for Table 3.2 must be interpreted with a degree of caution. A much better comparison

will be available once sound power screening has been completed again at the end of 2016.


5 RECOMENDATIONS

Global Acoustics would normally recommend that any plant with a sound power level change between test

periods of greater than 2 dB and/or an exceedance of a sound power limit by more than 2 dB, be initially

inspected for damaged or missing sound attenuation, further action to be determined from the outcomes of

said inspection. As BCM plant are not attenuated (with the exception of truck 938) this inspection would be

limited to the muffler/exhaust system.

Specific recommendations:

• A single CAT 785C truck to be tested under ISO/AS conditions to determine a more accurate sound

power level (the screening sound power level my be artificially elevated due to the test

methodology, but still be correct for the test methodology used);

• A single Komatsu 930E truck to be tested under ISO/AS conditions to determine a more accurate

sound power level (the screening sound power level my be artificially elevated due to the test

methodology, but still be correct for the test methodology used);

• A single Caterpillar D10T, D11T and D11R dozer to be tested under ISO/AS conditions to determine

a more accurate sound power level (the screening sound power level my be artificially elevated due

to the test methodology, but still be correct for the test methodology used);

• Dozer track tension is a significant contributor to dozer 'track slap' noise and should be monitored

and adjusted at regular intervals. Initially, these intervals would be close together until the

variability of track tension is determined (how well a dozer holds its set track tension); and

• Site noise levels at sensitive receptors with a source to receptor distance of greater than 4 km are

much more dependant on plant linear (dB) sound power levels than plant A-weighted (dBA) sound

power levels, as low frequency noise is attenuated to a lesser degree by molecular absorption. It is

recommended that the relevant linear sound power limits be sourced and used from this point

forward.

We trust this information is per your requirements. Please contact us if you require further details or advice.

Global Acoustics Pty Ltd


APPENDIX

A CALIBRATION CERTIFICATES



Documents

Boggabri Coal Mine - Idemitsu · 2020. 4. 30. · 21328 CAT 785C APX01262 12/01/2016 1st gear forward 131 122 119. 3. Stock Standard N 21329 CAT 785C APX01263 12/01/2016 1st gear