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Noise Calculator

You can open the calculator here: Noise calculator

 

... and this is the geeky part, where I explain the underlying maths:

Daily exposure

The basis for the calculator is the equation for daily noise exposure, L_EP,d:

L_EP,di = L_eq,i + 10 . Log₁₀(T_i/T₀)

where:

L_eq,i is the noise level (L_eq) during the exposure i;

T_i is the total daily exposure time to exposure i;

T₀ is the reference exposure time of 8 hours (28800 seconds).

Exposure Points

To get exposure points values, the HSE system is based on 100 points being the equivalent of L_EP,d = 85 dB(A). This is the Upper Exposure Action Value (UEAV) defined in the Control of Noise at Work Regulations 2005.

The equations for the Points Exposure P_E,i value is then:

P_E,i = 100 . (10^[(L_EP,d,i - UEAV)/10]

Adding exposures

To add daily exposure from difference machines or processes, the individual partial vibration exposures cannot be simply added together, daily exposure is given by:

L_EP,d,i = 10 . Log₁₀{(1/T₀) . sum[(T_i . 10^(L_eq,i/10)]}

The advantage of the exposure points system is that partial exposure points can be easily added, so daily exposure points is given by:

P_E = P_E,1 + P_E,2 + P_E,3 + ...

Conversion from points to daily exposure in dB(A) is given by:

L_EP,d = UEAV + 10 * log₁₀(P_E/100)

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