[Dongbo Meter] Audiometer Set 370×220×110mm (1pc/Individual)

Product Usage Instructions: - Instruction manual: 1) When using AC power || Insert the power supply unit into an AC220V outlet and turn on the power switch. - 2) When using DC power || Insert a DC9V 6F22 (FC-1) battery into the battery compartment and turn on the power switch. - 3) When the red indicator light is on, plug the headphones into the headphone jack. - 4) You can select and use frequencies from 500Hz to 4KHz by adjusting the frequency selection switch. - 5) Once the frequency is selected, you can adjust the volume from 0 to 100dB using the volume control knob, and read the scale numbers by multiplying by 10. - (Example: If the dial scale is at 3, then 3X10 = 30dB) - 6) After completing the above steps, press the test balance switch to hear sound from the headphones. - When you press the L button, you will hear sound from the left side, and when you press the R button, you will hear sound from the right side.