Velleman AVM2050 Handbuch Seite 2

5. Output
You can connect the AVM2050 to recording or other equipment through the OUTPUT connector. For example: use
an audio cable to connect the device to an AUX or LINE input of a recorder.
Always bear in mind that the output signal is influenced by the internal filtering process.
Set the RANGE selector to a value for which the maximum deviation of the meter is never more than +4 to prevent
the internal amplifier from removing the signal. Use the A weighting for recordings with voices and the C weighting for
entirely instrumental recordings. Connect the output with high impedance headphones, an oscilloscope, a frequency
analyzer or any other measuring instrument.
6. Response Time
The response switch has 2 positions: FAST and SLOW. FAST makes the meter react fast to sudden changes is the
sound level. This position is ideal for peak measurement. SLOW is used for average noise level measurements.
Short sound surges have little effect.
7. Weighting
The WEIGHTING switch is used to measure the sound level for a specific frequency range. A-weighting means the
meter will be measuring predominantly in the 500 - 10.000Hz frequency range. This range corresponds to the
frequencies most audible to the human ear. C-weighting concentrates on fixed sound levels between 32 and
10000Hz ; these are sound sources with a constant frequency and sound level.
8. Microphone
The measurements are most accurate when the meter is directed directly towards the sound source.
9. CAL (calibration)
The device has been calibrated very accurately. Normally, the device will not need to be recalibrated.
Contact your dealer if it should be done.
10. Measurements
• Do not keep the meter too close to your body when measuring ; the sound reflection could cause false results.
Keep the meter at arm's length and aim it straight toward the sound source.
• Take care when working with the AVM2050. The microphone and the part with the pointer are very sensitive. They
can easily be damaged when the device falls.
• Do not use the device in a humid environment
FOLLOW THESE STEPS TO DETERMINE THE APPROPRIATE RESPONSE, WEIGHTING AND RANGE:
1. Set the RESPONSE switch to FAST if the sound consists of short signals or when you only want to measure
sound peaks. Set RESPONSE to SLOW if you're more interested in an average value.
2. Set WEIGHTING to A if you want to measure the noise level and select C to measure the sound level of music.
3. Set the RANGE selector to the highest level (120dB) and lower it gradually until the pointer clearly moves.
Always set RANGE as low as possible for optimum accuracy.
Example: if RANGE is set to 80dB and the pointer indicates more or less -5, then set RANGE to 70dB so the
pointer can show +3 for a 73dB level.
Important: for correct results, the signal to be measured must be at least 10dB louder than the background noise.
The information in this manual is subject to change without prior notice.
AVM2050 - 2 - VELLEMAN