Ergonomics - Atlas Copco

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5 microphones Fig. 3.20 Testing noise levels in the laboratory according to ISO 15744. band frequency spectrum in cases where precise frequency information is important. The most common way to present noise is to let the signal pass a broad band filter that will give a single figure. There are a number of filters available. A, B, C and D filters, for example. The characteristics of the A filter correspond to those of the hu- man ear for low levels. However, the A filter is currently used at all levels to simplify the measurement process. The unit is dB(A). Noise test report Front end B&K Puls Standards There are standards for exposure measurements and laboratory measurements. Threshold Limit Values (TLV) for noise may differ from country to country. Computer with B&K Puls Software The European Directive 2003/10/EG, the Physical Agents (Noise) Directive, takes effect as national legislation not later than February 15, 2006. From that date it replac- es the old 86/188/EEC and gives the limit 117
118 value for 8 hours’ exposure to 87 dB(A) with attenuation provided by ear protectors taken into account. The directive also gives an upper and a lower action value of 85 and 80 dB(A), respectively, without ear protectors. When an action value is exceeded the employer must take actions defined in the directive. Dose meters that can be carried by the operator during a full working day are available for conducting these measurements. Laboratory measurements A standard was developed in the 1960’s for measuring the noise levels of hand-held power tools. It was the result of collabora- tion between Pneurop (the European Com- mittee of Manufacturers of Compressors, Vacuum Pumps and Pneumatic Tools) and CAGI (the Compressed Air and Gas Insti- tute, in the USA). The European Machine Directive states that machine manufacturers are required to declare noise emission levels from the tools. If the sound pressure level is above 85 dB(A), the sound power should also be stated. The latter statement has led to some confusion. Sound pressure levels and sound power levels use the same unit, dB(A). Sound power levels can be calculated from a number of sound pressure readings over a control surface. Pneurop and CAGI have r = 1m Fig. 3.21 Test surface containing five microphone positions. 1m produced two new standards incorporating estimation of sound power. They are now re- placed by the standard ISO 15744 published on March 15, 2002. At present, noise measurements are performed in accordance with ISO 15744 for pneumatic tools and EN 50144 or EN 60745 for electric tools. Test procedure The test object is held by an operator. The distance from the geometrical center of the machine to the microphones is 1 m. Four microphones are situated in a plane parallel to the floor, and one microphone is placed 1 m above the geometrical center of the machine.
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Power Tool Ergonomics E V A L U A T
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Acknowledgements While doing resear
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How to get the best out of this boo
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Work with international standards I
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Good ergonomics is good economics W
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10 SOCIOLOGY INDUSTRIAL SOCIOLOGY S
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12 Work organization No organizatio
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1 outside the production system, an
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1 A seated operator usually has goo
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1 without stretching the trunk. The
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20 The arm sling as a preventive me
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22 Extreme working postures in real
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2 Working with high feed forces req
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2 Working areas of a standing works
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2 body is lifted or tilted, or the
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30 The team is an important factor
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32 Grinders Grinders and sanders ar
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34 HanDle DeSiGn The hand grips on
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36 DUSt anD oil Although the machin
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38 Working environment In general,
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40 SHoCK reaCtion Sudden changes in
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42 practice. Sometimes the chisel h
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44 SHoCK reaCtion These tools do no
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46 heavy, assembly work is often hi
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48 depends on its inertia. The same
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50 bolts. Unfortunately there are a
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52 The low reaction torque in impul
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54 the working environment A typica
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56 Today, the angle nutrunner can b
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58 High torque nutrunners for use w
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60 Wheel nuts on trucks and buses a
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62 Introduction A basic ergonomic p
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64 Handle design The handle of a ha
Page 67 and 68: 66 Arteries Veins (superficial) Vei
Page 69 and 70: 68 Handle size Since a tool handle
Page 71 and 72: 70 However, if the texture is too c
Page 73 and 74: 72 Bibliography Chaffin, D.B. and A
Page 75 and 76: 74 Fig. 3.3 The same feed force app
Page 77 and 78: 76 Pushing and pulling Pushing a to
Page 79 and 80: 78 the object, the shape of the obj
Page 81 and 82: 80 Safety factor a 2 Frequency of t
Page 83 and 84: 82 Comments for different tool type
Page 85 and 86: 84 The trigger is either operated b
Page 87 and 88: 86 used in one handed operations. T
Page 89 and 90: 88 Weight The weight of a hand-held
Page 91 and 92: 90 stability of grip, the center of
Page 93 and 94: 92 Temperature Hand-held power tool
Page 95 and 96: 94 To ensure physical comfort durin
Page 97 and 98: 96 Score 40 30 20 10 0 Bibliography
Page 99 and 100: 98 the dynamic properties of the ma
Page 101 and 102: 100 High motor power and fast clutc
Page 103 and 104: 102 Score 40 30 20 10 0 shock react
Page 105 and 106: 104 piezo-electric crystal. When th
Page 107 and 108: 106 EN 50144 and EN 60745. Both ISO
Page 109 and 110: 108 hole of the wheel are wider tha
Page 111 and 112: 110 In the GTG 40 grinding machine,
Page 113 and 114: 112 RRH machines serves two functio
Page 115 and 116: 114 be noted that declared values b
Page 117: 116 Noise Noise was the first envir
Page 121 and 122: 120 We can start by looking at the
Page 123 and 124: 122 This is done with a minimum inc
Page 125 and 126: 124 microphones at a distance of 1
Page 127 and 128: 126 coated with dust or damaged by
Page 129 and 130: 128 This method has not been used b
Page 131 and 132: 130 tool cabinet. Many workplaces h
Page 133 and 134: 132 lubrication. Made from a compos
Page 135 and 136: 134 Grinder GTG 40 F085 The relevan
Page 137 and 138: 136 were simulated by fitting a whe
Page 139 and 140: 138 Drill LBB 26 EPX-060 The releva
Page 141 and 142: 140 applied to the center of the dr
Page 143 and 144: 142 Chipping hammer RRF 31 The rele
Page 145 and 146: 144 SHOCK REACTION There are no sho
Page 147 and 148: 146 Riveting hammer RRH 06 The rele
Page 149 and 150: 148 WEIGHT The weight is 1.3 kg, sc
Page 151 and 152: 150 Screwdriver LUM 22 PR4 The rele
Page 153 and 154: 152 This gives a score of 9. In pra
Page 155 and 156: 154 Impulse nutrunner EP9 PTX80-HR1
Page 157 and 158: 156 Due to friction in the hydrauli
Page 159 and 160: 158 Electric nutrunner ETP ST32-05-
Page 161 and 162: 160 WEIGHT The electric nutrunner i
Page 163 and 164: 162 Angle nutrunner LTV 29 R30-10 T
Page 165 and 166: 164 operator equal to installed tor
Page 167 and 168: 166 Electric angle nutrunner Tensor
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168 WEIGHT The electric nutrunner i
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170 High torque nutrunner LTP 51 Th
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172 Score 40 30 20 10 0 NOISE The d
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