🦺 Tsaron aiki — fallasa ga ƙara Samfurin kai-tsaye
Kai ne shugaban tsaro na ƙungiyar mutum shida a aiki na sa'o'i takwas. Wuri ɗaya yana da hayaniya — aikin gyara ko na'ura — sauran masana'antar kuma suna ƙara a ƙananan matakai. Kowane mintuna goma samfurin yana ƙara adadin hayaniyar kowane ma'aikaci bisa ƙa'idar fallasa da OSHA ta yarda da ita da iyakar da NIOSH ta ba da shawara, yana ƙirga kariyar da kayan kare kunnensu ke bayarwa a zahiri, kuma yana ƙididdige abin da ƙungiyar ke samarwa. Kwaikwayon ilimi kawai — ba shawarar doka, bin ƙa'ida ko likita ba.
Abin da za ka koya
Yadda kashi na ƙara ke taruwa: kowane 5 dB (OSHA) ko 3 dB (NIOSH) na ƙari yana raba lokacin da mutum zai iya zama zuwa rabi.
Dalilin da yasa alamar mai kariya ke ƙara girman kariyarsa, da kuma dalilin da yasa 'yan mintuna ba a sa ba a ƙara mai ƙarfi suke soke mafi yawanta.
Matsayin sarrafawa a aikace: da farko a rage ƙarar tushe, sannan a iyakance lokaci ta jujjuyawa, sannan a kare kunne.
Na'urar koyi
Lokaci 0 min
·Ma'aikaci, kashi ƙasa da 50 %
!Ma'aikaci, kashi 50–100 %
‼Ma'aikaci, kashi sama da 100 %
◉Yana da mai kariyar ji
≋Yanki a 95 dBA ko fiye
▭Shinge (an shigar / ana shigarwa)
Sarrafawa
Wanda ke cika matsayin masu ƙara. Tabbatattu = mutane iri ɗaya duk aikin; kowace sa'a = matsayin masu ƙara suna wucewa ta ƙungiya kowace sa'a; bisa kashi = kowace sa'a ma'aikata masu ƙarancin kashi suke ɗauka.
Aikin gyara yana ci gaba da mutum biyu a mafi yawa a wurin aiki; na'ura tana samarwa ga kowane mai aiki. Kowa a can yana fallasa.
Kowane ma'aikaci yana kashe mintuna 10 a kowace sa'a a ɗakin shiru, a jere. Ƙarancin fallasa, ƙarancin hannaye.
Raguwar da aka rage a fili (NRR − 7)/2: toshe na kumfa NRR 29 → 11 dB, murfin kunne NRR 25 → 9 dB, duka tare → 16 dB.
Yana ɗaga kason lokacin da ake sa masu kariya da gaske daga kusan 80 % zuwa kusan 97 %.
Yana dakatar da tushe nan take. Ƙungiyar mai ƙara tana tafiya zuwa layi; aikin ko fitarwar na'ura tana jira.
Allunan da ke kewaye da tushe suna rage shi da 10 dB bayan shigarwa na mintuna 60; aiki a ciki yana tafiya a hankali da kusan 10 %.
Yana zuwa bayan mintuna 30 da sabon kashi. Ƙungiya har zuwa takwas.
Alamomi
Mafi girman kashi na OSHA PEL
0%
daidai
Mafi girman kashi na NIOSH a kunne
0%
daidai
An kammala aiki mai ƙara
100%
daidai
Samarwa da shirin aiki
0%
mai tsanani
Mafi girman TWA na awa 8 (OSHA, ƙofar 80-dB)
40.0 dBA
Mafi girman TWA na awa 8 a kunne (NIOSH)
40.0 dBA
Hasashen kashi na PEL a ƙarshen aiki (da saurin yanzu)
0 %
Ma'aikata sama da kashi 100 % na PEL
0
Mataki a aiki mai ƙara
85.0 dBA
Mataki a layi
82.0 dBA
Ƙimar fitarwa
0 units/h
Ƙungiya a aiki
6
Ma'aikata masu masu kariya
0
Shigarwar shinge da ta rage
-1 min
Yanayi
Yanayin rikici
Mataki 1 · Aikin gyara mai ƙara
A 07:30 dole a fasa a maye rufin hopper: awannin ma'aikata uku a 104 dBA, a wannan aikin, kuma mutum biyu ne kawai ke shiga wurin aiki. Ba za a iya kafa allunan rufewa a cikin hopper ba, kuma ba a ba da wani kayan kare kunne ba da safen nan. Dole layi ya ci gaba da gudu. Kada kowa ya ƙare aiki sama da 100 % na adadin OSHA, kuma kunnuwa dole su kasance cikin iyakar NIOSH ma.
Mafi girman kashi na OSHA PEL ≤ 100 % a ƙarshe
Mafi girman kashi na NIOSH a kunne ≤ 100 %
An kammala aikin gyara a wannan aikin
Samarwa ≥ 95 % na shirin aiki
Mataki 2 · Ƙarancin masu kariyar ji
Isar da toshen kunne bai zo ba kuma akwai nau'i biyu na murfin kunne kawai a wurin. Na'urar yin siffa tana gudu duk aikin a 96 dBA da masu aiki biyu, kuma allunan shinge suna wani aiki. Ku tsara aikin don kada kowa ya wuce kashi na OSHA ko iyakar kunne ta NIOSH — kuma samarwa har yanzu ya cim ma shiri.
Mafi girman kashi na OSHA PEL ≤ 100 % a ƙarshe
Mafi girman kashi na NIOSH a kunne ≤ 100 %
Samarwa ≥ 95 % na shirin aiki
Mataki 3 · Matsin samarwa, sabuwar na'ura mai ƙara
Sabuwar na'urar yanka tana farawa a 07:30 don cika ɗaga tsari. Tana auna 103 dBA a wurin mai aiki kuma tana buƙatar masu aiki biyu. Matosai na kumfa suna hannu. Cika tsarin ba tare da kowa ya wuce adadin OSHA ko iyakar kunne ta NIOSH ba.
Mafi girman kashi na OSHA PEL ≤ 100 % a ƙarshe
Mafi girman kashi na NIOSH a kunne ≤ 100 %
Samarwa ≥ 95 % na shirin da aka ɗaga
Tushe — samfurin da ke bayan lambobin
Kowace alaƙa da na'urar koyi ke amfani da ita, tare da tushenta. Ƙayyadaddun ƙimomin da aka yi wa alama a matsayin zato daidaitawa ne na misali.
Matakan sauti suna haɗuwa a matsayin makamashi: tushe biyu daidai suna da ƙarfi da 3 dB fiye da ɗaya. Kowane yanki yana jin yanayinsa tare da tushen mai ƙara, wanda nisa da bango suka rage.
L_area = 10·log10(10^(L_bg/10) + 10^((L_src − spill − IL)/10)) + N(0, 1 dB)[6]Zato: yanayin yankuna, zubewa, asarar shigarwa ta shinge da lokacin isarwa, bin ka'idar sanyawa, ƙimar samarwa da bambancin matakai ƙimomi ne na misali don masana'anta ta gama-gari; ƙa'idodin kashi kansu waɗanda aka buga ne.
Kashi na OSHA: kowane lokaci C a mataki L yana amfani da C/T na yini, inda T ke raguwa zuwa rabi kowane 5 dB sama da 90 dBA. Jimilar 100 % ita ce iyakar fallasa da aka yarda da ita (PEL).
T = 8 / 2^((L − 90)/5) h; D = 100·Σ Cᵢ/Tᵢ (levels ≥ 90 dBA for the PEL, ≥ 80 dBA for the action level)[1][2][3]
Kashi da matsakaicin awa 8 mai la'akari da lokaci (TWA) bayani ɗaya ne: 50 % = 85 dBA (matakin aiki na shirin kare ji), 100 % = 90 dBA.
Iyakar da NIOSH ta ba da shawara: 85 dBA na awa 8, ana raba lokaci biyu kowane 3 dB — ƙa'idar makamashi daidai. A 100 dBA hakan mintuna 15 ne.
T = 8 / 2^((L − 85)/3) h (80–140 dBA integrated); TWA_NIOSH = 10·log10(D/100) + 85[4]
Alamomin masu kariya ƙimomin dakin gwaji ne. OSHA tana cire 7 dB don karatun A-weighted sannan ta raba sauran biyu; sa toshe da murfin kunne tare yana ƙara kusan 5 dB kawai ga wanda ya fi kyau.
Mintunan da ba a sa ba ana ƙirga su a cikakken mataki. Saboda makamashi yana haɗuwa, mai kariya da aka sa 80 % na lokaci a 100 dBA yana ba da ƙasa da ƙimarsa sosai.
ear dose per tick = w·r(L − A) + (1 − w)·r(L); w ~ N(c, 0.05) clipped to [0,1], c = 0.80 (0.97 enforced)[7][4]Zato: yanayin yankuna, zubewa, asarar shigarwa ta shinge da lokacin isarwa, bin ka'idar sanyawa, ƙimar samarwa da bambancin matakai ƙimomi ne na misali don masana'anta ta gama-gari; ƙa'idodin kashi kansu waɗanda aka buga ne.
Shinge yana rage matakin ga kowa kusa da tushe; jujjuyawa da hutu suna raba ko rage lokacin da ake kashewa a can kawai.
enclosure: L_src − 10 dB after 60 min, task productivity × 0.9; rotation/breaks change Cᵢ, not L[5][6]Zato: yanayin yankuna, zubewa, asarar shigarwa ta shinge da lokacin isarwa, bin ka'idar sanyawa, ƙimar samarwa da bambancin matakai ƙimomi ne na misali don masana'anta ta gama-gari; ƙa'idodin kashi kansu waɗanda aka buga ne.
Samarwa yana bin wurin da aka sanya ƙungiya: matsayi a kan layi da na'ura suna samarwa, ɗakin shiru ba ya samarwa.
output = Σ workers rate(area)·(1 + 0.1·z); loud job progress = min(n_loud, 2) × 10 minZato: yanayin yankuna, zubewa, asarar shigarwa ta shinge da lokacin isarwa, bin ka'idar sanyawa, ƙimar samarwa da bambancin matakai ƙimomi ne na misali don masana'anta ta gama-gari; ƙa'idodin kashi kansu waɗanda aka buga ne.
Sauran ƙayyadaddun ƙimomin aiki da samfurin ke amfani da su.
backgrounds: loud area 85, line 82, assembly 78, quiet room 62 dBA · source spill −20 dB at the line, −26 dB at assembly, −45 dB in the quiet room · line 3 posts at 1 unit per 10 min, assembly 0.5 · 10-min quiet break per hour, staggered · extra worker arrives after 30 min, crew ≤ 8Zato: yanayin yankuna, zubewa, asarar shigarwa ta shinge da lokacin isarwa, bin ka'idar sanyawa, ƙimar samarwa da bambancin matakai ƙimomi ne na misali don masana'anta ta gama-gari; ƙa'idodin kashi kansu waɗanda aka buga ne.
Rashin tsari: mai samar da mulberry32 mai iri; rarrabawar da aka yi amfani da su — uniform, exponential (inverse CDF), normal (Box–Muller), Poisson (Knuth). Ana nuna iri kuma ana iya raba shi.
D. A. Bies, C. H. Hansen, C. Q. Howard — Engineering Noise Control (decibel addition, enclosures and barriers, insertion loss) — CRC Press, 5th ed., 2017
E. H. Berger et al. (eds.) — The Noise Manual, 5th ed. (hearing protector field performance; effect of wearing time on effective attenuation) — American Industrial Hygiene Association, 2003