Sper Scientific 840012 Sound Meter with Detachable Probe - Manual (Page 5)

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Note: The Max/Min values are frozen and not updated until the meter
returns to recording mode.
•
To return to recording mode, press the HOLD (8) button. "REC" is
displayed without "Max" or "Min".
• To erase the recorded Max/Min values and exit the recording mode,
press the REC MAX/MIN (9) button for at least 2 seconds.
3-D. MAX HOLD: (Holds the max measurement on the display.)
• Press the MAX HOLD (10) button, “P.H” appears on the LCD.
• Press the MAX HOLD (10) button again to exit this function.
• NOTE: Select auto range when using this function in slow varying
noise environments. Select the appropriate manual range when
using this function in pulsing noise environments.
3-E. AC OUTPUT
The 3.5 mm diameter AC OUTPUT (14) may be used to connect the unit
to an external output device, such as an analyzer, recorder, or controller.
3-F. CALIBRATION
• The meter's CAL (15) adjustment is located on the side of the unit.
• Use Sper Scientific's 2 Pt. Acoustical Calibrator 850016 (or
equivalent) to calibrate the unit in compliance with OSHA.
• Press the POWER (7) button to turn the unit on.
• Turn the acoustical calibrator on and place it onto the meter's
MICROPHONE (1)
• To calibrate the meter to 94 dB, select the 50 ~ 100 dB range,
FAST response, and "A" weighting.
• Use the calibration screw driver to gently turn the CAL (15)
adjustment until the display reads 94.0.
• To calibrate the meter to 114 dB, select the 80 ~130 dB range,
FAST response, and "A" weighting and turn the CAL (15)
adjustment until the display reads 114 dB.
3-G. PRECAUTIONS
• Do not store or operate the unit in high temperatures or in high
humidity for long periods.
• Keep the microphone dry.
• Do not force the CAL (15) adjustment, doing so may damage the
mechanism and void the warranty.