Sper Scientific 840018 Sound Level Meter Pen - Manual (Page 4)

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III. Operating Instructions
Precautions and Maintenance
• Do not store or operate the instrument at
high temperatures or humidity.
• Keep the microphone dry and avoid se-
vere shock or vibration.
• Wind blowing across the microphone can
cause measurement errors, these effects
are reduced by using the windscreen.
• Remove the batteries if the unit is not in
use for a long period of time.
• Wipe the case with a dry cloth, do not
use abrasives or solvents.
Calibration
Calibrate the meter before first use or
when the reading appears inaccurate.
If you require a certificate of calibration
traceable to NIST, the unit may be sent to
Sper Scientific for servicing (fee applies).
There are two methods of calibration:
1. Internal Electrical Calibration
• With the unit on, lightly press the
Battery Cover to slide it down and off.
• Move the Measurement Slide Switch
down. This activates the built-in
oscillator (94dB 1 kHz, sine wave) for