DeltaOHM HD2010UC/A, Руководство по эксплуатации

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HD2010UC/A
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V4.1
Modern sound level meters, like HD2010UC/A, apply corrections that can modify micro-
phone responses according to the acoustic field in which they are used. In this way you can, for ex-
ample, make measurements in indoor environments, in presence of multiple sound sources and
anyway in a reverberant field, with a microphone optimized for free field, by activating the correc-
tion specific for random incidence. Applying this adjustment, the free field microphone will give a
response similar to that of a diffuse field microphone.
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NVIRONMENTAL INFLUENCE
Temperature
Sound level meters are designed to work at temperatures included in the range: -10°C ÷ +50°C.
Most accurate sound level meters, like HD2010, can have adjustment circuits for thermal drifts aim-
ing to reduce at minimum the measuring error over the whole temperature range. It is suggested,
however, to avoid sudden variations that might cause condensation. Furthermore, be sure that the
instrument is in thermal equilibrium before carrying out a measurement or a calibration (just wait an
hour after temperature has changed.
Humidity
The HD2010UC/A sound level meter and the microphone are not affected by relative humidity up
to 90%. However, protect the microphone from rain and snow and keep it clean. In case of bad
weather, it is suggested to use a windshield and, in case of use in very humid environments, the
proper microphone dehumidifier should be applied.
Pressure
Microphone sensitivity depends on atmospheric pressure. Microphone sensitivity depends on at-
mospheric pressure. Sensitivity increases as pressure decreases and the change of sensitivity for the
HD2010UC/A with the UC52 microphone measured at 250 Hz is always lower than ±0.03 dB/kPa
in the range 85 kPa ÷ 108 kPa as required by IEC 61672 for Class 1 sound level meters. Sensitivity
drift with ambient pressure is usually worst at high frequencies, even if the sensitivity maximum
difference in the range 85 kPa ÷ 108 kPa remains within ±0.5 dB over the whole sound spectrum.
Wind
To reduce wind disturbance as much as possible, it is suggested to use the proper windshield, con-
sisting of a polyurethane porous globe to be placed on the microphone.
This useful accessory protects also from dust, dirt, rain and snow. The presence of a windshield
slightly alters the microphone frequency response and more accurate sound level meters are pro-
vided with a correction curve to compensate this effect.
Vibrations
Even though microphone and sound level meter cannot be easily affected by vibrations, it is better
to isolate both instrument and microphone from strong vibrations.
Magnetic Fields
The influence of electrostatic and magnetic fields on the sound level meter is negligible.
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RECAUTIONS AND GENERAL HINTS OF USE
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Ensure that ambient conditions fit the use of a sound level meter. Take care that the instrument
has reached thermal equilibrium, that there is no condensation on metal walls and that tempera-