3M 1200 User Manual - Meter Integrity
1200/2200 Sound Level Meter Operator’s Manual
7
Meter Integrity
3. METER INTEGRITY
3.1 Power On and Battery Check:
Set the OFF/PAUSE/RUN switch to either the PAUSE or RUN position as
desired. At any time, other than initial turn-on, if the LOBAT indicator is
displayed, the user must replace the battery. A 9 Volt Alkaline battery is
recommended for best performance.
3.1.1 Battery Replacement:
Slide the battery door to the left to open the battery compartment. Refer to
the sticker inside the compartment for proper battery orientation.
3.1.2 Rechargeable Batteries:
Nicad type rechargeable (9V batteries (such as Radio Shack
®
23-299 7.2 V,
120 mAh) and an appropriate charger may be used with the 1200. The
fact that nicad 9 V replacement cells typically operate at 7.2 V will be
observed as shorter battery life (approximatelt 8 hours with Radio Shack
®
23-299). At the appearance of the LOBAT indicator the nicad battery must
be recharged.
NiMH (Nickel-Metal-Hydride) batteries are NOT recommended. This is
due to the excessive discharge of the typical NiMH cell prior to the
voltage dropping low enough to activate the LOBAT indicator.
3.2 Setup:
NOTE: There may be times when it is necessary to change the Exchange
Rate or Calibration Level that is stored in the meter. Both of these items
are accessible during the power-up sequence.
The power-up sequence is as follows:
1. All display segments turned on for 2 seconds.
2. The meter firmware revision ‘rX.X’ for 2 seconds.
3. The current Exchange Rate or Doubling Rate ‘Er3’ or ‘Er5’ for 3
seconds.
4. The current Calibration Level for 3 seconds.
3.2.1 Changing the Exchange Rate:
Turn on the meter.
When ‘Er3’ or ‘Er5’ appears in the display, press both the CAL and
RESET button simultaneously until dashes are displayed.
1200/2200 Sound Level Meter Operator’s Manual
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Meter Integrity
At this point, pressing either the CAL or RESET button will toggle the
Exchange Rate between ‘Er3’ and ‘Er5’.
When the desired Exchange Rate is displayed, store the selection by
pressing both the CAL and RESET buttons simultaneously. This com-
pletes the selection.
3.2.2 Changing the Calibration Level:
NOTE: The calibration level is the decibel level that is produced by
your calibrator.
Turn on the meter.
When the current calibration level is displayed, press and hold both the
RESET and CAL buttons until dashes appear. The meter is now in the
calibration level set mode.
To edit the level, use the RESET key to increase the value and the CAL
key to decrease to value. Edit the value to match your calibrator’s output.
When the desired calibration level is displayed, press and hold both the
RESET and CAL buttons until dashes appear on the display. The new
calibration level is now stored in the instruments memory and will not
have to be changed again unless an alternate calibrator is used.
3.3 Calibration:
The model 1200 may be calibrated in any range based on your calibrator’s
output. There is no warm up period required, but for maximum accuracy
calibration should be performed at the temperature of the environment to
be measured. To calibrate, perform the following procedure using a Quest
Calibrator.
It is recommended that calibration be performed before each use.
1. Check that the LOBAT indicator is not on.
2. Check to see that the calibrator SPL output matches the calibration
level stored in the meter. If it does not, use procedure outlined in
section 3.2.
NOTE: Failure to match calibrator output level to calibration level stored
in the 1200 will result in erroneous SPL readings.