Dosímetros acústicos de ruido datalogger 407355 EXTECH manual ingles www.viaindustrial.com
Dosímetros acústicos de ruido datalogger 407355 EXTECH manual ingles www.viaindustrial.com
5
10. To end the noise survey, press and hold the RUN key for 3seconds. Read the accumulated
noise exposure value on the LCD.
11. Testing notes:
Never shout into the microphone as this will affect the test.
To obtain reliable data, the user’s activities must reflect atypical working day.
For best results, test over the course of several days and average the %DOSE
Refer to the dosimetry parameter descriptions below:
EVENT
SELECT
Press the EVENT button to enter the EVENT mode. Each time the EVENT button is pressed the
LCD increments the Event bank (E1 through E5). Each bank is amemory location. The user can
store (or write over) the data in any of these locations. Each bank location (E1, for example) is
displayed on the LCD along with the stored data. If data is present in abank, the bank ID blinks.
To erase data in abank, press and hold the RESET button until the display ID stops blinking.
%
DOSE
The unit of measure, %DOSE, is used to quantify noise exposure measured during awork shift.
100% dose is the maximum allowable noise exposure in accordance with OSHA,
MSHA, DOD,
ACGIH,
and ISO standards. Most
standards specify Criterion Level, Exchange
Rate, Response
Time, and Frequency weighting for the dosimeter as discussed next.
CRITERION
LEVEL
(Lc)
To
take
an
on-site
noise
exposure
survey
in
accordance
with
standards
such
as
OSHA
and
MSHA, the dosimeter’s Criterion Level must first be set. The 100% DOSE parameter discussed
above is determined by the following equation: 100% DOSE =Criterion Level for 8hours. Each
country
has
a
unique
Criterion
Level
(most
countries,
including
the
U.S.,
use
90dB).
The
Criterion
level
is
selectable
(80,
84,
85,
or
90dB).
Select
the
appropriate
level
per
the
Programming section of this manual.
EXCHANGE
RATE
(ER)
Exchange rate is best illustrated by example; refer to the following example: Since 100% DOSE
=
Criterion
Level
for
8
hours,
a
person
would
receive
50%
DOSE
in
4
hours
if
the
noise
level
equals the Criterion Level setting. Now consider aCriterion Level of 90dB, anoise measurement
of 95dB (5dBA higher than the Criterion Level), and an Exchange Rate of 5dB; in this example a
100%
DOSE
would
be
received
in
only 4
hours.
This
is
because with
a
5dB
Exchange
Rate,
a
5dB increase in sound level is considered adoubling of the DOSE. Other Exchange Rates can
be selected (3, 4, 5, or 6dB). Refer to the local regulations or standards.
FAST
(F)
SLOW
(S)
RESPONSE
TIME
Set the response time to Fast (F) to capture quick bursts of sound such as discharging firearms,
fireworks, hammering, and other impulse noises. Use the Slow (S) setting if the noise under test
is
more
of
a
continuous
drone
or
background
din.
The
Slow
setting
is
typically
specified
by
OSHA and MSHA standards for use in noise surveys. Refer to the Programming section of this
manual to set the response time.
THRESHOLD
LEVEL
(Lt)
The
threshold
level
is
the
sound
level
at
which
the
407354
begins
to
integrate
noise
into
the
exposure test. For example, if the threshold level (Lt) is set to 85dB, the meter
will integrate all
noise that equals or exceeds 85 dB. Sound levels below this threshold would not be included in
the dose calculation. See the Programming section to change the level. The Threshold Level can
be set from 70 to 90dB in 1dB steps.
PEAK
FLAG
When sound levels above 140dB are present the meter displays the
PK
symbol.
HIGH
LEVEL
INDICATOR
When sound levels above 115dB are present the meter displays the headphone symbol.