407764 Datasheet, PDF(5/12 Page) Extech Instruments Corporation.

English

English German Russian Spanish Italian Polish Chinese Japanese Korean French Portuguese	Language :

407764 Datasheet, PDF (5/12 Pages) Extech Instruments Corporation. – Datalogging Sound Level Meter

◁

Operation

1. Power the meter and select the desired Response Time (Fast or Slow) and Frequency

Weighting (A or C).

2. Select the desired range.

3. Hold the instrument comfortably in hand or position on tripod. Point the microphone

toward the noise source, the sound pressure level will be displayed on the meterâs LCD

display.

4. When MAX (maximum hold) mode is selected by pressing the MAX key, the instrument

captures and holds the maximum noise level reading on the display. Press the MAX key

again to clear the MAX reading.

Calibration

Note that a Sound Level Calibrator is required. Set up the meter as listed in Step 1 below.

To calibrate the meter;

1. Display: SPL (dBA)

Response Time: FAST

Disable the MAX function

Range: 70 to 120dB.

2. Insert the microphone carefully into the sound

level calibrator.

3. Power the calibrator and adjust the Sound Level Meterâs

CAL potentiometer (as shown in figure at right) to match

the Calibratorâs output.

4. Typically, a Sound Level Calibrator will supply 94dB

or 114dB at 1KHz. Adjust the Sound Level Meterâs CAL

potentiometer for a 94dB or 114dB LCD display

(Figure-3)

Analog output

The 407764 has two analog output jacks located on its right side; one for AC and one for DC.

For DC, the meter transmits 10mv / dB. For AC the full scale value is 0.707V. The output

The supplied 3.5mm stereo mini-plug can be used to assemble a cable to connect to either of

the meterâs analog output jacks. When using a stereo plug, like the one supplied, short the Tip

and the Ring (see diagram below). Ground (negative) connects to the Sleeve while the positive

signal is taken from the Tip/Ring. For mono plugs, ground connects to the Sleeve while the

positive signal is taken from the Tip. The meter output can then be transmitted to a chart

recorder, datalogger, or other data storage device.

(Figure 4)

Sleeve Tip

Stereo

Ring

Sleeve Tip

Mono

Model 407764 Version 2.1 9/07

▷