Panametrics C-ET, Руководство по установке

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Model C-ET Installation Guide 9
1.3.2 Obtaining the Transducer Spacing
1.3.2.1 Determining Special Transducer Parameters
The C-ET transducers must be programmed in the flowmeters as special transducers. As specials, four parameters
are required: Frequency, Tw, Wedge Angle, and Wedge Soundspeed.
Frequency : Frequency is determined based on the part number of the C-ET transducer, and it can be found on the
C-ET label.
Figure 4: C-ET Parameters Label
The CRS-XX-MB defines the frequency of the transducers as follows:
If “XX” = 05, then the frequency =.5MHz.
If “XX” = 10, then the frequency = 1MHz.
Tw : Tw (time in wedge) is determined by the transducer frequency, nominal process temperature, and ambient
temperature using Graph #1 (Figure 5 on page 10) or Graph #2 (Figure 6 on page 11) based on the transducer
frequency.
As an example:
If Transducer Frequency = 0.5MHz
Ambient Temperature = 20°C
Nominal Process Temperature = 340°C
Tw would be: 150µs
Wedge Angle : Wedge angle is determined by the nominal process temperature and ambient temperature using
Graph #3 on page 12 similar to Tw above.
As an example:
If Ambient Temperature = 20°C
Nominal Process Temperature = 340°C
Wedge Angle would be: 57.2 degrees
Wedge Soundspeed : Wedge soundspeed is always 10104.9 ft/s (3080.0 m/s) for the C-ET transducer.