407355 Version 2.4 9/07

8

Calibration Procedure

Note that an acoustical calibrator (such as the Extech 407744 or 407766) is required to

calibrate the 407355. Extech Instruments can also calibrate the instrument and provide an

N.I.S.T. certificate if desired.

1. Set the instrument to the Sound Level Measurement Mode (dBA) using the MODE

button.

2. Set the response time to SLOW (see the Programming section)

3. Insert the 407355 microphone into the microphone cavity of the calibrator.

4. Turn the calibrator ON and adjust the CAL screw on the 407355 so that the LCD

display matches the calibrator output signal (94dB typically).

5. Calibration should be performed before each use.

PC Interface

Connecting the meter to the PC via the supplied interface cable

Connect the 5-pin end of the supplied interface cable to the DOSE Meter. Connect the 9-

pin connector end of the cable to the PC COM Port. Cable and adaptor wiring are detailed

later in this manual for reference.

Installing the supplied DOSE Windows

1. Insert the supplied software CD in the PC CD-ROM drive.

2. Follow the on-screen instructions for installation of the DOSE software program.

3. Open the DOSE program from the location where it is installed on the PC.