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[MERGED] Occupational Safety & Health /NIOSH
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Post Last Edit by DewaGanaZ at 5-2-2010 23:39
earmuff tak tentu berkesan kalau noise level terlalu tinggi...
ikutkan, earplug lagi berkesan daripada earmuff
kalau nak beli ear muff or ear plug, tengok NRR dia kat kotak/packet dia
NRR= Noise Reduction Rating. Unit dB(C)..selalu kat kotak tulis sebagai dB aje sebab NRR memang dalam C...so kalau jumpe kat kotak jgn keliru db tu adalah pada pemberat C.
utk tukar weigthing C ke A, tolak 7dB pada NRR (correction factor=7)
contoh ear plug dengan 20 db (C) NRR
bunyi kawasan sekitar yg diukur = 90dB(A)
so bunyi yg masuk kat ear plug ke telinga = 90 -(NRR-7)
so, 90-(20-7)=90-13=77dB
so maknanya earplug tu dapat sekat sebanyak 13db(A) noise and bunyi yg sampai ke gegendang telinga adalah 77dB(A)
utk bacaan lanjut
http://www2.cdc.gov/hp-devices/pdfs/calculation.pdf
http://www.elvex.com/NRR.htm
so kalau nak beli earplug/earmuff, pilih betol2 based on noise level di tempat kerja n NRR
kalau utk repirator/mask depa guna APF (Assigned Protection Factor)
leh baca sini http://www.trustcrm.com/ectny/re ... expose/apf/apf.html
ni panduan utk pilih the right PPE
sekian kelas saya...kalau tak paham angkat tangan |
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Post Last Edit by DewaGanaZ at 5-2-2010 23:39
earmuff tak tentu berkesan kalau noise level terlalu tinggi...
ikutkan, earplug lagi berkesan daripada earmuff
kalau nak beli ear muff or ear plug ...
DewaGanaZ Post at 5-2-2010 23:29 
mcmane pulak ngn SNR tuh??..apa dia??
pastu utk respirator tuh...fit testing kuanti dan kuali tuh mcmane?? |
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leh tanye member aku ni..shamsul sho kat airport takpun mas ehs korporat |
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Post Last Edit by DewaGanaZ at 5-2-2010 23:39
earmuff tak tentu berkesan kalau noise level terlalu tinggi...
ikutkan, earplug lagi berkesan daripada earmuff
kalau nak beli ear muff or ear plug ...
DewaGanaZ Post at 5-2-2010 23:29 
oh,ada calcualation...tq..tq |
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Post Last Edit by DewaGanaZ at 6-2-2010 22:09
mcmane pulak ngn SNR tuh??..apa dia??
pastu utk respirator tuh...fit testing kuanti dan kuali tuh mcmane??
pressor Post at 6-2-2010 11:57 AM 
ikutkan pemahaman aku NRR digunakan oleh US and negara2 yg ikut US punyer method macam kita kat Malaysia ni... FYI, most dosh punyer regulations with regards to industrial hygiene banyak yg ikut US... so kita guna NRR jugak... beza dalam Noise REgulations kita, kita masih pakai 5dB sebagai exchange rate tapi negara2 maju lain i.e US dah guna 3dB
SNR plak term yg digunakan di EU.... berbeza sikit dengan NRR
Kita di sini pakai NRR aje...tapi kalau beli PPE biasanya dah ade NRR
SNR [Single Number Rating] – is number rating used by countries within the
European Union and affiliated countries calculated from Assumed Protection
Values according to a method given in Annex D of BS EN ISO 4869-2:1995
"Acoustics - Hearing protectors - Part 2: Estimation of effective A-weighted sound
pressure levels when hearing protectors are worn". Tests are conducted at
independent testing laboratories, using frequencies which are slightly different
than those used for the NRR rating.
In addition to an overall rating, the SNR
further rates protectors in terms of the particular noise environments in which
they will be used – H for high-frequency noise environments, M for mid-frequency
and L for low-frequency. Note that the HML designation does not refer to noise
level, rather the spectrum of the noise. For example, a protector might be
designated with SNR 26, H=32, M=23, L=14. The estimated attenuation changes
according to the noise spectrum of the environment in which the protector is to
be worn. The SNR rating is the result of a lengthy mathematical calculation – it
gives us a single-number rating of a hearing protector’s attenuation for a
specified percentage of the population. The SNR is significantly lower than the
average attenuation across all of its test frequencies as the calculation contains
correction factors to make it applicable to the broader population. While it is not
the perfect real-world measure of attenuation, SNR is a very useful standardized
method for describing a hearing protector’s attenuation in a single number. For
instant if an environment has an a weighted noise measurement of 100dbA then
by using an earplug with an SNR rating of 25db it will reduce the noise to 75db,
the precautionary action level is 80dbA, where hearing protection has to be
offered and audiometric testing training programs implemented.
soalan nko pasal fir test tu aku kurang paham la bro...
ape fir test kuantiti and fit test kualiti??
Biasa respirator memang kena ade buat fit test sebelum pakai..... diff brand ade different method....
harap nko leh specific..aku takde ler tererr sangat, tapi nak gak belaja ni
makcik, pengiraan kecil2an aje
lom lagi soh kire daily dose or nak tambah db..hehe
did u know 20db+20dB tak dapat 40dB?? |
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Post Last Edit by DewaGanaZ at 6-2-2010 22:09
ikutkan pemahaman aku NRR digunakan oleh US and negara2 yg ikut US punyer method macam kita kat Malaysia ni... FYI, most dosh punyer regulations ...
DewaGanaZ Post at 6-2-2010 22:02
dewa,tadi aku check earplug yg stok kitaorg , SNR29....
bnyk sgt info kt kotak tu,haram aku tau pon...
by the way...why 20db + 20db tak sama ngan 40db? sbb ada interferens kah?  |
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be right back lepas layan final destination 3....hehehehehe |
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aku nak rate ko takleh...nanti kambeng masok sini,dia rate la ko |
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Post Last Edit by pressor at 7-2-2010 09:03
Post Last Edit by pressor at 7-2-2010 08:57
 pening sudah....
pasal fit testing tuh..bukan ke dia ade 2 kuantitatif ngn kualitatif (maafkan ku kalo silap)....aku nak tau mcmane kekdah dia buat....validity wat fit test...wajib ke utk semua org yang nak pakai fit test...ade requirement dr DOSH tak??
mmm..maaf bengap sket....exchange rate tuh apa??
beb..kalo amek kos noise monitoring yang kat NIOSH tuh dia akan ajar semua nih ke??? |
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1695# pressor
posting press kena sorok dek hantu kopek |
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dewa,so between SNR ngan NRR, lebih elok jenis NRR ke? |
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Post Last Edit by pressor at 7-2-2010 09:03
Post Last Edit by pressor at 7-2-2010 08:57
pening sudah....
pasal fit testing tuh..bukan ke dia ade 2 kuantitatif ngn kualitatif (maafka ...
pressor Post at 7-2-2010 08:55 AM
hmm...aku tak pasti plak ade kualitatif and kuantitatif... kalau kuantitatif tu camne?? brape banyak yg kita test??
ikutkan takde ler wajib..maybe sunat aje kot...hehe
but according to USECHH Rgulations, majikan mesti established PPE Program in its workplaces... and fit test nih satu elemen aje dalam ppe programm ni...
ikutkan kita kena pakai betol2 PPE ni..cara nak pakai ni la lebih kuang macam fit test....
contoh respirator yg 2 catrij tu... fit test dia senang...
pakai macam biasa and then letak tapak tangan kat depan katrij tu..then sedut.... kalau kedap aje udara dalam tu maka cukup fit..
and then tutup dengan tapak tangan lubang 'angin' depan tu..then hembus..kalau betol2 fit repirator akan terangkat.... kalau tak bocor la kiri kanan..means fit tak semestinya pakai ketat2....so ini yg ramai org nyampah pakai pasal kena pakai ketat2 padahal x semestinya...depend dengan size ppe n bentuk muka
ok ke jawapan aku nih?? jgn jadikan jawapan aku ni reference...aku bantai aje ikut pengalaman aku..hehe |
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Category: Belia & Informasi
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Post time 5-2-2010 07:49 PM
bukan ke dah terbiasa...
