How a Noise Meter Works
A noise spectrum analyzer is a measuring instrument for noise. Used for spectrum analysis of various industrial noises, and can also be used for environmental noise measurement.
A-weighted sound level can better reflect the subjective perception of the human ear towards the intensity and frequency of noise. Therefore, for a continuous steady-state noise, it is a good evaluation method. However, for a fluctuating or discontinuous noise, A-weighted sound level appears inappropriate. For example, traffic noise varies with vehicle flow and types; For example, when a machine is working, its sound level is stable, but due to its intermittent operation, a machine with the same sound level but continuous operation has a different impact on humans. Therefore, a problem was proposed to evaluate the impact of noise on humans using the time averaged method of noise energy, namely the equivalent continuous sound level, denoted as "Leq" or "Laeq · T". It represents the magnitude of noise during the same period of time using a continuous and stable A-sound level with equal sound energy. For example, there are two machines with a sound level of 85dB. The first machine works continuously for 8 hours and the second machine works intermittently, with a total effective working time of 4 hours.
Obviously, the average energy applied to the operators is twice as much as the former, which is 3dB greater than the latter. Therefore, the equivalent continuous sound level reflects the actual amount of noise energy that a person receives when the sound level is unstable. It is an equivalent quantity used to express the time-varying noise.
What are the common faults of noise meters
As is well known, vibrations can produce noise such as rotating machinery, impact, resonance, friction, as well as noise generated by flow fields, environmental noise, combustion noise, and other noises. The generation of noise has an impact on our daily life and work. To determine the magnitude of noise, a noise measuring instrument is required.
1. No display on the monitor
(1) Internal battery wiring disconnected or poor battery contact: Weld the wiring and replace the battery contact piece. (2) Battery damage: Replace the battery.
2. The measurement reading is significantly low or cannot be calibrated to 94.0dB.
(1) The sensitivity of the microphone is too low or damaged: replace the microphone and recalibrate it.
(2) The contact between the preamplifier and the microphone is not good: clean the contact.
(3) The plug of the preamplifier is not in good contact with the host socket: replace the plug socket.
3. The reading is high during low sound level measurement, and the ground contact of the preamplifier is poor: tighten the outer sleeve.
