Confirm that you understand the procedures for calibrating each of the instruments you use. If in doubt, review instructions in each instrument's user's manual and consult CTC if questions arise. In general, as long as the sound level readout is within 0.2 dB of the known source (the calibrator output), it is suggested that no calibration adjustments be made. If large fluctuations (greater than 1 dB) in the level occur, then either the calibrator or the instrument may have a problem.
Additionally, confirm that you know how to change or charge the battery in both the calibrator and the instruments. If in doubt, review instructions in each instrument's user's manual. A low battery is the number-one cause of equipment failing pre- and post-use calibration. Changing the battery will often bring the equipment back into an acceptable calibration range immediately, but a little practice is needed to change the battery quickly on some equipment. Most rechargeable batteries cannot be changed in the field so it is even more important their charge status is known and changed as necessary prior to instrument usage. Rechargeable batteries that can no longer be recharged must be replaced by CTC or the manufacturer. Be prepared, so that a low battery doesn't slow you down during an early morning calibration session (Figure 15).
Whether detachable or integrated into a sound level meter, an octave band analyzer receives its daily calibration in conjunction with the sound level meter with which it will be used. This might involve activating an additional setting during the daily meter calibration. Consult the user's manual for the equipment you will be using.
Some octave band analyzers can be set to automatic function (i.e., the instrument automatically checks the sound level of each frequency band and stores the results). Other instruments require the user to manually switch between the different frequency bands, recording each reading in sequence.
When monitoring is complete at the end of the day, follow standard procedures for recording results from the instruments. If necessary, consult the instrument user's manual or contact CTC for assistance. Dosimeter output usually includes the TWA (normalized to 8 hours), the LAVG or LEQ representing the average dose for the period monitored, the percent dose, and the maximum or peak reading. Do not neglect to perform the post-use calibration check on each instrument.
Audiograms may be recorded as a graph, in table format, or on a paper ticket. The key frequencies for review are 2,000, 3,000, and 4,000 Hz in each ear. Results should be evaluated for each ear separately; a threshold shift can occur in one ear and not the other. There are smartphone applications that will automatically calculate STS values and perform age correction. If a smart phone application is used during an investigation, some manual calculations should also be conducted to verify the application is correctly calculating STS values.
We have placed this Electronic Version of our current and past gun safe manuals here for your convenience. To determine which owner's manual is the correct version for your Liberty Safe, locate the safe's SERIAL NUMBER. Recent models show the serial in two locations: