[{"data":1,"prerenderedAt":616},["ShallowReactive",2],{"site-footer-common":3,"glossary:osha-29-cfr-1910-95":45,"glossary-related:osha-29-cfr-1910-95":161},{"id":4,"extension":5,"footer":6,"meta":40,"navbar":41,"stem":43,"__hash__":44},"common\u002Fcommon.yml","yml",{"tagline":7,"links":8,"sections":9},"Acoustic cleaning intelligence for industrial fouling, soot, ash, dust and build-up.",[],[10,19,31],{"title":11,"links":12},"Product",[13,16],{"label":14,"to":15},"How it works","\u002F#product",{"label":17,"to":18},"Cost assessment","\u002F#hero",{"title":20,"links":21},"Company",[22,25,28],{"label":23,"to":24},"What we build","\u002F#about",{"label":26,"to":27},"Careers","\u002F#careers",{"label":29,"to":30},"Contact","\u002F#contact",{"title":32,"links":33},"Resources",[34,37],{"label":35,"to":36},"Blog","\u002Fresources\u002Fblog",{"label":38,"to":39},"Glossary","\u002Fglossary",{},{"links":42},[],"common","YocmZRy1AYfBbpgGVms-zhdiABlF8VTxHx6h4rDmZBA",{"id":46,"title":47,"aliases":48,"body":52,"category":142,"description":143,"extension":144,"meta":145,"navigation":146,"path":147,"relatedTerms":148,"seo":152,"sources":155,"stem":159,"term":47,"__hash__":160},"glossary\u002Fglossary\u002Fosha-29-cfr-1910-95.md","OSHA 29 CFR 1910.95",[49,50,51],"OSHA noise standard","29 CFR 1910.95","OSHA Occupational Noise Exposure",{"type":53,"value":54,"toc":136},"minimark",[55,62,78,83,92,95,113,117],[56,57,58,61],"p",{},[59,60,47],"strong",{}," is the US Occupational Safety and Health Administration's standard for occupational noise exposure in general industry. Two thresholds matter:",[63,64,65,72],"ul",{},[66,67,68,71],"li",{},[59,69,70],{},"Action level"," — 85 dBA TWA (time-weighted average over an 8-hour shift) — triggers a hearing-conservation programme",[66,73,74,77],{},[59,75,76],{},"Permissible exposure limit (PEL)"," — 90 dBA TWA — at which engineering controls or hearing protection are mandatory",[79,80,82],"h2",{"id":81},"how-it-interacts-with-sonic-horn-installations","How it interacts with sonic-horn installations",[56,84,85,86,91],{},"A ",[87,88,90],"a",{"href":89},"\u002Fglossary\u002Fsonic-horn","sonic horn"," at the work area can exceed 130 dBA SPL at close range. Operators within ear-shot of firing horns require hearing protection; permanent personnel exposure must be calculated as time-weighted average given the horn duty cycle and operator distance.",[56,93,94],{},"Mitigation options:",[63,96,97,104,107,110],{},[66,98,99,103],{},[87,100,102],{"href":101},"\u002Fglossary\u002Fsound-attenuation-enclosure-sonic-horn","Sound-attenuation enclosures"," at the bell",[66,105,106],{},"Operator-station relocation outside the near-field",[66,108,109],{},"Hearing-protection requirements during horn operation",[66,111,112],{},"Acoustic monitoring during operator-presence audits",[79,114,116],{"id":115},"related-terms","Related terms",[63,118,119,125,131],{},[66,120,121],{},[87,122,124],{"href":123},"\u002Fglossary\u002Fsound-pressure-level","Sound pressure level",[66,126,127],{},[87,128,130],{"href":129},"\u002Fglossary\u002Feu-directive-2003-10-ec","EU Directive 2003\u002F10\u002FEC",[66,132,133],{},[87,134,135],{"href":101},"Sound-attenuation enclosure (sonic horn)",{"title":137,"searchDepth":138,"depth":138,"links":139},"",2,[140,141],{"id":81,"depth":138,"text":82},{"id":115,"depth":138,"text":116},"standards-regulations","OSHA 29 CFR 1910.95 is the US Occupational Safety and Health Administration's standard for occupational noise exposure in general industry. Two thresholds matter:","md",{},true,"\u002Fglossary\u002Fosha-29-cfr-1910-95",[149,150,151],"sound-pressure-level","eu-directive-2003-10-ec","sound-attenuation-enclosure-sonic-horn",{"title":153,"description":154},"OSHA 29 CFR 1910.95 — US occupational noise exposure standard","OSHA 29 CFR 1910.95 sets US occupational noise exposure limits. The action level is 85 dBA TWA; the permissible exposure limit is 90 dBA TWA. Calculated from time-weighted average exposure.",[156],{"title":157,"url":158},"OSHA — Occupational Noise Exposure","https:\u002F\u002Fwww.osha.gov\u002Flaws-regs\u002Fregulations\u002Fstandardnumber\u002F1910\u002F1910.95","glossary\u002Fosha-29-cfr-1910-95","hQ4_HWPAzxwdcLfEZpimG9KRjWxsXOs-TaAZIXPg29c",[162,354,498],{"id":163,"title":164,"aliases":165,"body":168,"category":334,"description":335,"extension":144,"meta":336,"navigation":146,"path":123,"relatedTerms":337,"seo":342,"sources":345,"stem":352,"term":124,"__hash__":353},"glossary\u002Fglossary\u002Fsound-pressure-level.md","Sound pressure level (SPL)",[166,167],"SPL","sound pressure level dB",{"type":53,"value":169,"toc":328},[170,188,192,268,272,285,289,303,305],[56,171,172,174,175,179,180,182,183,187],{},[59,173,164],{}," is the logarithmic measure of sound pressure relative to the 20 µPa human-hearing reference, expressed in ",[87,176,178],{"href":177},"\u002Fglossary\u002Fdecibel","decibels",". It is the primary specification figure for any ",[87,181,90],{"href":89}," or ",[87,184,186],{"href":185},"\u002Fglossary\u002Facoustic-cleaner","acoustic cleaner"," and the metric used to size noise-exposure controls at the work area.",[79,189,191],{"id":190},"industrial-reference-values","Industrial reference values",[193,194,195,208],"table",{},[196,197,198],"thead",{},[199,200,201,205],"tr",{},[202,203,204],"th",{},"SPL (dB)",[202,206,207],{},"Reference",[209,210,211,220,228,236,244,252,260],"tbody",{},[199,212,213,217],{},[214,215,216],"td",{},"0",[214,218,219],{},"Threshold of human hearing",[199,221,222,225],{},[214,223,224],{},"60",[214,226,227],{},"Normal conversation",[199,229,230,233],{},[214,231,232],{},"120",[214,234,235],{},"Threshold of pain",[199,237,238,241],{},[214,239,240],{},"140",[214,242,243],{},"Industrial sonic horn (lower-output models)",[199,245,246,249],{},[214,247,248],{},"160",[214,250,251],{},"Typical cement \u002F ESP sonic horn",[199,253,254,257],{},[214,255,256],{},"180",[214,258,259],{},"Upper limit of pneumatic industrial sonic horns",[199,261,262,265],{},[214,263,264],{},"194",[214,266,267],{},"Theoretical maximum for an undistorted sine wave in air",[79,269,271],{"id":270},"spl-and-cleaning-effectiveness","SPL and cleaning effectiveness",[56,273,274,275,279,280,284],{},"Cleaning energy scales with intensity, which doubles for every 3 dB rise. A 150 dB horn delivers roughly twice the energy of a 147 dB horn at the same distance. SPL is not, however, the only selection criterion: ",[87,276,278],{"href":277},"\u002Fglossary\u002Ffrequency","frequency"," determines ",[87,281,283],{"href":282},"\u002Fglossary\u002Fwavelength","wavelength"," and therefore penetration. A 150 dB low-frequency horn typically out-cleans a 160 dB high-frequency horn in a large open vessel.",[79,286,288],{"id":287},"spl-and-exposure","SPL and exposure",[56,290,291,292,296,297,299,300,302],{},"Reported nameplate SPL is measured at 1 m on the bell axis. Real exposure at the work area falls with distance per the ",[87,293,295],{"href":294},"\u002Fglossary\u002Finverse-square-law","inverse-square law"," and through enclosure attenuation. Compliance with ",[87,298,47],{"href":147}," and ",[87,301,130],{"href":129}," is calculated from exposure, not from nameplate SPL.",[79,304,116],{"id":115},[63,306,307,312,317,323],{},[66,308,309],{},[87,310,311],{"href":177},"Decibel",[66,313,314],{},[87,315,316],{"href":277},"Frequency",[66,318,319],{},[87,320,322],{"href":321},"\u002Fglossary\u002Fsound-power-vs-sound-pressure","Sound power vs sound pressure",[66,324,325],{},[87,326,327],{"href":294},"Inverse-square law",{"title":137,"searchDepth":138,"depth":138,"links":329},[330,331,332,333],{"id":190,"depth":138,"text":191},{"id":270,"depth":138,"text":271},{"id":287,"depth":138,"text":288},{"id":115,"depth":138,"text":116},"acoustics-physics","Sound pressure level (SPL) is the logarithmic measure of sound pressure relative to the 20 µPa human-hearing reference, expressed in decibels. It is the primary specification figure for any sonic horn or acoustic cleaner and the metric used to size noise-exposure controls at the work area.",{},[338,278,339,340,341],"decibel","sound-power-vs-sound-pressure","inverse-square-law","sonic-horn",{"title":343,"description":344},"Sound pressure level (SPL) — definition, industrial-cleaning ranges","SPL is the logarithmic measure of sound pressure in decibels relative to a 20 µPa reference. Industrial sonic horns operate at 140–180 dB SPL.",[346,349],{"title":347,"url":348},"Wikipedia — Sound pressure","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FSound_pressure",{"title":350,"url":351},"Acoustical Society of America — Sound Pressure Level","https:\u002F\u002Fasastandards.org\u002F","glossary\u002Fsound-pressure-level","ayEoQNuJweSv9WGpwDPcx5CMESsbiPd4QPUpIoyQA6M",{"id":355,"title":130,"aliases":356,"body":360,"category":142,"description":485,"extension":144,"meta":486,"navigation":146,"path":129,"relatedTerms":487,"seo":489,"sources":492,"stem":496,"term":130,"__hash__":497},"glossary\u002Fglossary\u002Feu-directive-2003-10-ec.md",[357,358,359],"2003\u002F10\u002FEC","EU noise directive","Physical Agents (Noise) Directive",{"type":53,"value":361,"toc":480},[362,371,391,395,406,410,461,464,466],[56,363,364,366,367,370],{},[59,365,130],{}," (also called the ",[368,369,359],"em",{},") sets workplace noise-exposure limits across EU Member States. Three thresholds matter:",[63,372,373,379,385],{},[66,374,375,378],{},[59,376,377],{},"Lower exposure action value"," — 80 dBA daily (Member States must provide hearing protection)",[66,380,381,384],{},[59,382,383],{},"Upper exposure action value"," — 85 dBA daily (must be used, engineering controls considered)",[66,386,387,390],{},[59,388,389],{},"Exposure limit value"," — 87 dBA daily (must not be exceeded, even with hearing protection)",[79,392,394],{"id":393},"industrial-sonic-horn-implications","Industrial sonic-horn implications",[56,396,397,398,401,402,405],{},"The directive applies to all EU industrial workplaces. Workplaces with installed ",[87,399,400],{"href":89},"sonic horns"," must conduct noise-risk assessments, often deploying ",[87,403,404],{"href":101},"sound-attenuation enclosures",", implementing operator-distance restrictions during horn firing, and requiring hearing protection in adjacent areas.",[79,407,409],{"id":408},"comparison-with-us-osha","Comparison with US OSHA",[193,411,412,427],{},[196,413,414],{},[199,415,416,419,422],{},[202,417,418],{},"Threshold",[202,420,421],{},"EU 2003\u002F10\u002FEC",[202,423,424],{},[87,425,426],{"href":147},"US OSHA 29 CFR 1910.95",[209,428,429,440,451],{},[199,430,431,434,437],{},[214,432,433],{},"Lower action",[214,435,436],{},"80 dBA",[214,438,439],{},"—",[199,441,442,445,448],{},[214,443,444],{},"Upper action \u002F PEL",[214,446,447],{},"85 dBA",[214,449,450],{},"90 dBA",[199,452,453,456,459],{},[214,454,455],{},"Exposure limit",[214,457,458],{},"87 dBA",[214,460,439],{},[56,462,463],{},"The EU directive is more stringent than the US OSHA standard in absolute terms, particularly at the upper action level.",[79,465,116],{"id":115},[63,467,468,472,476],{},[66,469,470],{},[87,471,47],{"href":147},[66,473,474],{},[87,475,124],{"href":123},[66,477,478],{},[87,479,135],{"href":101},{"title":137,"searchDepth":138,"depth":138,"links":481},[482,483,484],{"id":393,"depth":138,"text":394},{"id":408,"depth":138,"text":409},{"id":115,"depth":138,"text":116},"EU Directive 2003\u002F10\u002FEC (also called the Physical Agents (Noise) Directive) sets workplace noise-exposure limits across EU Member States. Three thresholds matter:",{},[488,149,151],"osha-29-cfr-1910-95",{"title":490,"description":491},"EU Directive 2003\u002F10\u002FEC — workplace noise exposure rules","EU Directive 2003\u002F10\u002FEC sets noise-exposure limits for EU workplaces. Lower action 80 dBA, upper action 85 dBA, exposure limit 87 dBA, all daily averages.",[493],{"title":494,"url":495},"EUR-Lex — Directive 2003\u002F10\u002FEC","https:\u002F\u002Feur-lex.europa.eu\u002Flegal-content\u002FEN\u002FALL\u002F?uri=CELEX:32003L0010","glossary\u002Feu-directive-2003-10-ec","hRoOXvEkDoKPXQONC3NVWwnFXe-7hcB2e1frGZQrQLA",{"id":499,"title":135,"aliases":500,"body":504,"category":603,"description":604,"extension":144,"meta":605,"navigation":146,"path":101,"relatedTerms":606,"seo":607,"sources":610,"stem":614,"term":135,"__hash__":615},"glossary\u002Fglossary\u002Fsound-attenuation-enclosure-sonic-horn.md",[501,502,503],"sound enclosure","acoustic enclosure","noise-attenuation enclosure",{"type":53,"value":505,"toc":598},[506,524,528,542,546,577,579],[56,507,85,508,511,512,514,515,517,518,299,521,523],{},[59,509,510],{},"sound-attenuation enclosure"," surrounds a ",[87,513,90],{"href":89}," installation to reduce the external ",[87,516,166],{"href":123}," experienced at the operator station, walkways and plant boundary. Typical SPL reduction is 10–25 dB depending on enclosure design — significant enough to bring exposures within ",[87,519,520],{"href":147},"OSHA",[87,522,421],{"href":129}," action limits at most realistic operator distances.",[79,525,527],{"id":526},"when-enclosures-are-specified","When enclosures are specified",[63,529,530,533,536,539],{},[66,531,532],{},"Sonic horns mounted close to operator-access walkways or maintenance positions",[66,534,535],{},"Multi-horn arrays where cumulative SPL exceeds the limit even at modest distance",[66,537,538],{},"Plant boundaries close to residential or commercial property",[66,540,541],{},"Indoor installations where reflection raises ambient SPL",[79,543,545],{"id":544},"trade-offs","Trade-offs",[63,547,548,554,565,571],{},[66,549,550,553],{},[59,551,552],{},"Cost"," — enclosures typically add 10–20% to the installed cost of the horn system",[66,555,556,559,560,564],{},[59,557,558],{},"Maintenance access"," — must be designed to allow routine ",[87,561,563],{"href":562},"\u002Fglossary\u002Fdiaphragm-replacement-sonic-horn","diaphragm replacement"," and inspection",[66,566,567,570],{},[59,568,569],{},"Thermal management"," — for hot-side installations, enclosure ventilation must prevent overheating of accessories",[66,572,573,576],{},[59,574,575],{},"Slight SPL reduction inside the vessel"," — usually marginal, but worth checking in marginal-coverage cases",[79,578,116],{"id":115},[63,580,581,586,590,594],{},[66,582,583],{},[87,584,585],{"href":89},"Sonic horn",[66,587,588],{},[87,589,124],{"href":123},[66,591,592],{},[87,593,47],{"href":147},[66,595,596],{},[87,597,130],{"href":129},{"title":137,"searchDepth":138,"depth":138,"links":599},[600,601,602],{"id":526,"depth":138,"text":527},{"id":544,"depth":138,"text":545},{"id":115,"depth":138,"text":116},"controls-ancillaries","A sound-attenuation enclosure surrounds a sonic horn installation to reduce the external SPL experienced at the operator station, walkways and plant boundary. Typical SPL reduction is 10–25 dB depending on enclosure design — significant enough to bring exposures within OSHA and EU 2003\u002F10\u002FEC action limits at most realistic operator distances.",{},[341,149,488,150],{"title":608,"description":609},"Sound-attenuation enclosure — reduces sonic-horn noise at the work area","A sound-attenuation enclosure surrounds the sonic horn to reduce SPL at the operator station. Typical 10–25 dB reduction; required where horn proximity exceeds OSHA \u002F EU action levels.",[611],{"title":612,"url":613},"Wikipedia — Noise control","https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FNoise_control","glossary\u002Fsound-attenuation-enclosure-sonic-horn","FR-H0qOqUvf8TGgdJbftenNX1Kg25JjWSxU9992_BLY",1782613756292]