730/730-IS Dosimeter Manual
B-6
of the quantity and not the quantity itself. The word decibel is often added after the number to express the same
thing. When frequency weighting is used the annotation is often expressed as dB(A) or dB(B). See also
L
max
The maximum value, expressed in dB, of the Frequency and Exponential-Time Weighted Sound Level (
L
ωτ
) in a
given time interval. For the dosimeters, an L
max
value is recorded for 2 different time intervals. The first records
L
max
for the entire record’s time. The second records L
max
for each individual time history sample.
L
min
The minimum value, expressed in dB, of the Frequency and Exponential-Time Weighted Sound Level (
L
ωτ
) in a
given time interval. For the dosimeters, an L
max
value is recorded for 2 different time intervals. The first records
L
max
for the entire record’s time. The second records L
max
for each individual time history sample.
Measurement Duration (t)
The time period of measurement. It applies to hearing damage risk and is generally expressed in hours. Standard:
ANSI S12.19
Noise Dose (Dose)
Noise Dose (Dose on the meter interface), is the percentage of time a person is exposed to noise that is potentially
damaging to hearing. Zero represents no exposure and 100 or more represents complete exposure.
The allowed time of exposure is determined by the Criterion Duration and by the sound level (the higher the level,
the shorter the allowed time). The sound levels must be measured with A-frequency weighting and slow
exponential time weighting.
OR
Peak
The maximum value of the instantaneous, frequency weighted (A, C, or Z), sound pressure in a given time interval.
For the dosimeter, a Peak value is recorded for 2 different time intervals. The first records the Peak for an entire
record’s run time (Peak Overall). The second records the Peak for each individual time history sample.
The peak level displays on the meter as L
<frequency weight>
peak; L
Apeak
is an example.
L
AS
= A-weighting frequency and slow-exponential
time weighting sound level in dB. If the sound
level is less than the user specified threshold
level, then L
AS
= –∞)
L
avg
= average sound level in dB, only records
values higher than the user specified threshold
level
L
C
= Criterion Level in dB
T = measurement period or Run Time (T = T
2
– T
1
)
T
C
= Criterion Duration in hours (8 hours)
q = exchange rate constant
• If exchange rate = 3, q = 10
• If exchange rate = 4, q = 4 / log
10
(2) ≈ 13.29
• If exchange rate = 5, q = 5 / log
10
(2) ≈ 16.61
• If exchange rate = 6, q = 20
