User's Guide Digital Sound Level Meter Model 407730
Introduction Congratulations on your purchase of the Extech 407730 Digital Sound Level Meter. The 407730 measures and displays sound pressure levels in dB from 40 to 130dB. User selectable features include Frequency Weighting (‘A’ and ‘C’), Response Time (Fast and Slow), Max Hold, and Max/Min recording. Careful use of this meter will provide years of reliable service. Meter Description 1. Microphone 2. LCD Display 3. ON-OFF button 4. A/C weighting selection button 5. Min/Max Record button 6.
Operation 1. Power the meter by pressing the power button. The meter will begin displaying sound level readings. If the LCD does not switch on, check the 9V battery located in the rear battery compartment. 2. Hold the meter away from the body. 3. View the measurement on the meter’s display. If the meter is in the autoranging mode, the display may briefly indicate “HI” or “LO” if the noise level is above or below the currently selected range. The meter will change the range as needed to display the dB level.
MAX/MIN Recording In this mode the meter records the Maximum and Minimum readings and stores them into memory. 1. Press the REC button to enter the RECORD mode. The “REC” icon will appear in the display. 2. Press the REC button again to display the minimum value recorded since the mode was entered. The “MIN” icon will appear in the display. The meter is not recording during this time. 3. Press the REC button again to display the maximum value recorded since the mode was entered.
Measurement Considerations 1. Wind blowing across the microphone increases the noise measurement. Use the supplied windscreen to cover the microphone when applicable. 2. Calibrate the instrument before each use if possible. Especially if the meter has not been used for a long period of time. 3. Do not store or operate the instrument in areas of high temperature or humidity. 4. Keep meter and microphone dry. 5. Avoid severe vibration. 6.
