DAKOTA ULTRASONICS PZX-7DL, Руководство по эксплуатации

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CHAPTER EIGHT
ADDITIONAL FEATURES
8.1 Gain
The gain, or amplification of the return echoes, can be adjusted in the PZX-7 DL to
accommodate a variety of materials and applications. The setting of the gain is
crucial in order to obtain valid readings during the measurement process. Too much
gain may result in erroneous measurements, detecting on noise rather than the
actual material back wall surface. Not enough gain may result in intermittent
detection. If you turn it up too much, you can’t hear the music clearly. If it’s turned
down too much, you can’t hear it at all.
The
PZX-7 DL
has the option of using and selecting three different transducer types;
contact, delay line, and plastics. The contact and plastics types in pulse-echo (P-E)
and plastics (PLAS) modes (PLAS; “thin” setting only), use manual gain and have
five gain settings
(VLOW, LOW, MED, HIGH, VHI) in 3dB increments, while the delay
line style transducers use automatic gain control (AGC), and have 3 gain settings
(LOW, MED, HIGH) . The
PZX-7 DL
has been optimized for the MED gain setting for
all common applications. It should be operated in this mode as standard. However,
some applications may require the lower or higher gain settings. When? The low
settings may be necessary for noisy or granular cast materials. How do I know when
to lower the gain? If the reading becomes sporadic and won’t settle down or resolve
on a thickness value because the material is either very noisy or granular. Setting
the gain to a lower less sensitive level, would potentially offer improved stability.
How do I know when to increase the gain? When a material is difficult to penetrate or
pass sound through. This could be due to the material type, overall thickness, the
transducer diameter and frequency, or a combination of all the above. Turning the
gain up for additional output could improve the ability to obtain a successful
measurement. In any case, the selectable gain settings offer improved versatility to
resolve and overcome potential application issues.
Note:
When the echo-echo (E-E) or plastics (PLAS), thick plastic setting option,
measurement modes are selected for either contact, delay line, or plastics modes,
The automatic gain control (AGC) is enabled. The dynamic range of the AGC can be
adjusted with the following options (LOW, MED, HIGH), with MED still being the
optimized standard setting as above.
The procedure for adjusting the gain is outlined as follows:
GAIN