Extech Instruments 407780A User Manual page 18

Calibration:
Acoustical calibrator (Extech 407744 or equivalent)
Calibration check frequency is 1000Hz.
Nominal calibration level for the free field: 94.1dB
Nominal calibration level for the diffuse field: 94.0dB
Frequency for acoustic testing: 8000Hz
Warm‐up time:
Sampling interval:
Data record capacity:
LCD Display
Display screens:
4 digit numerical indication of sound level, from 30.0 to 130.0dB with 0.1dB resolution.
Bar‐graph indication of current sound level with 1dB resolution.
Sound level range indicator: 30–90dB, 40–100dB, 50–110dB, 60–120dB or 70–130dB in five
ranges.
Time display; year – month – day and hour: minute: second.
Display update rate: 1 second
Display's start‐up indication: Depends on the condition of meter when it was last switched off.
Warning indications:
Out‐of‐range indications:
OVER displayed at upper limit of the range
UNDER displayed at lower limit of the range
Outputs
AC output (using selected frequency weighting)
Output voltage:
Output impedance: 5kΩ
Load impedance:
DC output
Output voltage:
Output impedance: 5kΩ
Load impedance:
I/O connector:
Alarm output:
800.561.8187
≤ 2min
Bar graph indication  125 ms approx.
Numeric indication  1 sec approx.
Data can be stored in memory.
Max. 32000 readings can be stored
Max. 255 blocks
2Vrms (at full‐scale of the range)
≥ 1MΩ
10mV/dB
≥ 1MΩ
Sound level meter control from, and data output to, PC (USB)
5Vdc, typical
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407780A‐EU‐EN v1.3 4/14