Tripod Mounting; Alarm Output - Extech Instruments 407780A User Manual

External power source
Insert the plug of an AC adaptor or external battery pack into the DC 6V (DC source from 5V to
6V) socket on the side of the instrument. When a connector is inserted into this socket, the
internal batteries will be disconnected and the instrument will be powered from the external
source. The low battery symbol
insufficient for the instrument to provide accurate measurements.
Note: Ensure that the external power source is connected with the polarity as indicated in the
following diagram; otherwise damage may be caused to the instrument and external power
source.
Windscreen
When making measurements in strong winds, wind noise and strong air movements at the
microphone can cause measurement errors. Such effect can be reduced by using the
windscreen.
Tripod Mounting
For long‐term measurements, the instrument may be mounted on a standard camera tripod
using the rear integral ¼" x 20 UNC mounting thread.
Alarm output
If the measured dB level exceeds the set limit, the over limit signal will appear at the alarm
output connector (5Vdc output). The output signal will remain active as long as the sound level
exceeds the set limit
Setting the sound level alarm high limit:
1. Switch the meter OFF.
2. Press and hold the LEQ SEL SPL button while switching the meter ON.
3. Release the LEQ SEL SPL button; the ALARM symbol (along with the currently set limit) is
displayed.
4. Use the ▲ ▼ buttons to set the desired sound level high limit value.
5. Press LEQ SEL SPL button to store the setting and to exit this mode.
Software Installation and Operation
For installation and operating instructions, please refer to the contents of the supplied CD‐
ROM.
800.561.8187
will appear on the display if the external voltage is
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