Operation - Extech Instruments 407355-NIST User Manual

Operation

Getting Started
1. Power the instrument by pressing the green
2. When the unit is turned on, all display items switch on briefly followed by 'dOSE', the Criterion
Level (Lc), Threshold Level (Lt), and Exchange Rate (ER) respectively. These parameters are
defined in the Noise Exposure related sections of this manual.
3. If the meter does not switch on when the power button is pressed, check that the batteries are
installed and are fresh. Refer to the Battery Replacement section of this manual.
4. To turn the meter OFF, press and hold the green power button; the display will count down from
3dB to 0dB and then switch off.
5. The 407355 can be used as a Sound Level Meter or a Dosimeter.
6.
Sound Level Meter Operation (dBA mode)
Press the MODE button repeatedly until the unit of measure is dBA (A-weighted decibels).
In SLM mode the meter operates as a Type 2 sound level meter. The 407355 measures and
displays sound pressure levels from 70 to 140dB. Read the measured sound level on the LCD. For
Sound Level measurements < 68dBA the LCD will display dashed lines.
For readings > 115dBA, the headphone
For readings > 140dBA, the Peak Detector PK icon appears.
Datalogging
In Sound Level Meter (dBA) mode, the internal memory of the meter can store up to 8800 readings.
1. Press the RUN key to start recording the measured readings. The MEM icon will appear in the
display.
2. To stop datalogging, press the RUN key again. The MEM icon will no longer be displayed on the
screen.
3. To download the data to a PC, refer to the PC Interface section in this manual.
Dosimeter Operation (%DOSE mode)
1. Program the Response Time (Fast or Slow), Criterion Level (Lc), Exchange Rate (ER), and
Threshold Level (Lt) manually (see Programming section) or program these parameters through
the supplied software (see PC Interface section).
NOTE: Make sure you have enough memory to complete your noise survey.
See ERASE MEMORY section before proceeding
2. Use the MODE button to select %DOSE as the unit of measure.
3. Select an unused Event Bank (E1 through E5) using the EVENT button. (Event is NOT flashing)
4. Attach the meter to the user's belt buckle, breast pocket, or where convenient
5. Clip the microphone as close as possible to the user's ear (shirt collar, for example) using the
lapel clip.
6. Route the cable as to not hinder the working movements of the user.
7. Press the RUN button to begin measuring accumulated noise exposure.
The Clock display icon will appear on the display.
8. Press the RUN button momentarily to PAUSE the test (PAUSE display icon will switch on).
Press the RUN button again to resume the test (PAUSE icon will switch off).
button.
icon appears.
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