Version 3.2 8/07

6

MAX Hold

The MAX display indicates and holds the highest dB level measured

since the meter was turned on or since the Max Reset button was

pressed. The time and date of the max reading is also displayed.

To clear the display and start a new measurement session, press the

front panel MAX RESET button. If the measured level exceeds the

maximum for the range selected the MAX display will indicate “OL” (overload).

Programmable OFF/ON/AUTO time

The meter is powered by 8 AA batteries or via an AC adaptor for permanent installations.

Continuous battery life is approximately 240 hours (10 days). By programming the ON/OFF

paragraph. The meter will operate continuously with the power switch in

the ON position. The ON/OFF time will be controlled by the meter when

the power switch is set to the AUTO position.

Calibration

The sound level meter should be calibrated on a regular basis

to assure that the meter’s performance and microphone

sensitivity has not change. Some operational directives

require daily calibration checks (OSHA). Extech offers several

acoustic calibrators to perform the calibration.

1. Set the meter to the 60 to 110dB or 80 to 130dB range.

2. Place the external calibrator over the Sound Level

Monitor's microphone and turn the Calibrator on.

3. The meter should read close to the calibrator's dB output

level. Typical Calibrator output levels are 94dB and 114dB.

4. If the meter is within ± 0.2 dB of the calibrator’s output, no

adjustment is necessary.

5. Adjust the calibration pot on the rear of the meter to the

proper level.

Meter Placement

The meter can be used Handheld, Wall mounted, Desk mounted or Tripod mounted. For

wall mount operation, orient the microphone perpendicular to the wall to minimize the

affect of acoustic reflections. For desk mounting, extend the rear legs and lock in place

with the hinged locks. The tripod mounting nut is located on the bottom of the unit.