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7.3.3 Hardware setup
"Backlit" can be set as "Open" constantly or selected within 10s-900s with 10s inter-
vals. When the user doesn’t press any keys in the specified time, the Backlight is
automatically turned off.
"Bright": default value is 25 which can be chosen between 4 and 49. When the value is
greater, the backlight is brighter.
"Mic. Type": free field (0°), pressure field (90°) and random can be chosen. The micro-
phone used in sound level meter is the type of free field, and it should point to sound
source when we take measurement which is incidence of 0°, and the microphone mode
should be set as free field (0°). But under some circumstances, the sound source only
can income at 90°, and the directivity of the microphone at high frequency will affect
the accuracy, the microphone mode should be set as pressure field (90°). The user can
use the function to change the free field microphone to pressure field microphone. The
influence that the three options of response frequency is seen in Annex.
"GPS": GPS power has three options: Open, Save, Close. If "Open", GPS module’s power
supply keeps running all the time, the power consumption is high, but the positioning is
fast. If "Save", GPS module’s power supply is turned on when necessary. Every time that
GPS module’s power supply is turned on, it needs several seconds to make reposition-
ing. When the GPS positioning signal is poor, it needs long time to make repositioning. It
is suggested that the user set it to "Open". When the user doesn’t needs the GPS
positioning information, "Close" may be set to save energy.
"Zone+8": the time zone where is the instrument is the difference between the local
time and the GMT or UTC. GMT+8 means the local time is 8h earlier than then GMT, the
instrument will automatically add 8h to the UTC of GPS as the local time when is doing
the GPS calibration.
