407355 Version 2.4 9/07

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9. Use the MODE button at any time to view the elapsed time of the test. Press the

MODE button until the TIME display icon appears. Now the elapsed time will appear in

hours and minutes. Press the RUN button again to return to the %DOSE display.

10. To end the noise survey, press and hold the RUN key for 3 seconds. 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 a typical 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 a memory

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 a bank, the bank ID blinks. To erase data in a bank, 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 a

work 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 8 hours. 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 a Criterion

Level of 90dB, a noise 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 a doubling 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 1 dB steps.