Zana ya Uhandisi Isiyolipisha
Kalkuleta ya Kuwa na Marudio ya Kelele
Kokotoa muda unaoruhusiwa wa mfiduo wa kelele na dozi kulingana na Maelekezo ya EU 2003/10/EC na viwango vya OSHA. Ingiza kiwango cha kelele na muda wa mfiduo ili kupata tathmini ya hatari yenye rangi za kuonyesha hatua.
Results
Muda Unaoruhusiwa wa Mfiduo
Muda unaoruhusiwa wa mfiduo unakokotolewa kutoka kwa kiwango cha kelele, kiwango cha marejeleo, na kiwango cha ubadilishaji:
Noise Dose
Dozi ya kelele kama asilimia ya kikomo kinachoruhusiwa:
Wastani wa Uzito wa Muda (TWA)
Kiwango cha kelele sawa na masaa 8:
Where:
- L — kiwango cha kelele kilichopimwa (dBA)
- Lref — kiwango cha marejeleo: 85 dBA (EU) au 90 dBA (OSHA)
- ER — kiwango cha ubadilishaji: 3 dB (EU) au 5 dB (OSHA)
- t — muda halisi wa mfiduo (masaa)
- Tpermitted — muda wa juu unaoruhusiwa wa kukabiliwa (masaa)
Mfano wa Vitendo
T = 8 / 2(92−85)/3 = 8 / 22.333 = 8 / 5.04 = 1.59 hours
Dose = (6 / 1.59) × 100% = 378%
TWA = 92 + 10 × log₁₀(6/8) = 92 − 1.25 = 90.8 dBA
Hatari: Dozi 378% > 200% → Hatari — hatua ya haraka inahitajika
⚠️ Note: Maximum permissible time at 92 dBA is only 1 hour 35 minutes under EU standard. Immediate noise reduction measures and hearing protection are mandatory.
Viwango vya Kelele vya Vyanzo vya Kawaida
| Source | Kiwango cha Kawaida (dBA) | Muda Unaoruhusiwa (EU) | Muda Unaoruhusiwa (OSHA) |
|---|---|---|---|
| Mazungumzo ya kawaida | 60 | Unlimited | Unlimited |
| Vacuum cleaner | 70 | Unlimited | Unlimited |
| Msongamano wa magari / Ofisi wazi | 80 | 25.4 hours | Unlimited |
| Factory floor | 85 | 8.00 hours | Unlimited |
| Hand drill | 90 | 2.52 hours | 8.00 hours |
| Kusaga / Msumeno wa umeme | 95 | 0.79 hours | 4.00 hours |
| Circular saw | 100 | 0.25 hours | 2.00 hours |
| Kinu cha nyundo / Kufunga riveti | 105 | 4.7 min | 1.00 hour |
| Jackhammer | 110 | 1.5 min | 30 min |
| Injini ya ndege ya abiria (umbali wa m 30) | 140 | ≈ 0.09 sec | ≈ 28 sec |
All times are computed from the calculator formula T = 8 / 2(L−Lref)/ER (EU: Lref = 85 dBA, ER = 3 dB; OSHA: Lref = 90 dBA, ER = 5 dB) and apply to steady, continuous equivalent A-weighted levels (LAeq) only. Peak and impulse noise is assessed separately — EU Directive 2003/10/EC sets a peak exposure limit of 140 dB(C) (LCpeak) regardless of duration — and hearing-protector attenuation must be derated for real-world fit before crediting it against these exposures.
Muda Unaoruhusiwa wa Kukabiliwa kulingana na Kiwango cha Kelele
| Kiwango cha Kelele (dBA) | EU (kiwango cha ubadilishaji wa dB 3) | OSHA (kiwango cha ubadilishaji cha 5 dB) |
|---|---|---|
| 85 | 8 h 00 min | —* |
| 88 | 4 h 00 min | —* |
| 90 | 2 h 31 min | 8 h 00 min |
| 91 | 2 h 00 min | 6 h 58 min |
| 94 | 1 h 00 min | 4 h 36 min |
| 95 | 47 min | 4 h 00 min |
| 97 | 30 min | 3 h 02 min |
| 100 | 15 min | 2 h 00 min |
| 103 | 7 min 30 sec | 1 h 19 min |
| 106 | 3 min 45 sec | 52 min |
| 109 | 1 min 53 sec | 34 min |
| 112 | 56 sec | 22 min |
| 115 | 28 sec | 15 min |
* Kiwango cha marejeleo cha OSHA ni 90 dBA; viwango chini ya 90 dBA havina kikomo cha muda cha OSHA (PEL hizidishwi kwa masaa 8).
Vifaa vya kitaalamu vya kusawazisha rotors vinavyofanywa uwanjani, vyenye uchanganuzi wa mtetemo uliojengwa ndani. Punguza kelele za mashine chanzo chake kwa kusawazisha kwa usahihi. Vinatumika katika nchi 50+ duniani kote.
