Siemens SITRANS FUS1020, Manual, Page: 140 / 251

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1020NFM-1D Section 6
To select a Transducer Model:
To access the [Transducer Model] option list press the <Right Arrow>.
To move the cursor to the required transducer model press the <Up/Down Arrows>.
To store your selection press <ENTER>.
6.4.2 HOW TO SELECT A TRANSDUCER SIZE
When you move the cursor to [Transducer Size], the highlighted prompt at the top of the display
screen shows a list of recommended transducer sizes. For example
[Recommended Xdcrs: B1,
B2, C1, C2] . The flow computer generates this list automatically based on your pipe and your applica-
tion data entries. The left-most transducer size (e.g., B1) is the primary (most appropriate) choice.
The right-most transducer (e.g., C2) is still acceptable (but the least desirable) choice. Since these
are simply recommendations not requirements, you can override the flow computer and use any size,
as long as the mounting method accommodates the pipe’s diameter. The flow computer shows that
your selection is acceptable if it is able to calculate transducer spacing (Ltn).
To select a Transducer Size:
To access the [Transducer Size] option list press the <Right Arrow>.
To move the cursor to the desired transducer size press the <Up/Down Arrows>.
To select the transducer size press <ENTER>.
6.4.3 HOW TO SELECT A XDCR MOUNT MODE
The flow computer recommends the transducer mounting mode [Direct or Reflect]. In almost all cases
it will be Reflect, since this is the most desirable configuration. Reflect Mode allows you to mount the
transducers on pipes that do not permit back or side access. Reflect Mode provides inherent compen-
sation for flow profile distortion (crossflow) that could be the result of unfavorable application condi-
tions such as an insufficient upstream straight run. In addition, Reflect Mode supports the AutoZero
function, which sets the zero flow velocity automatically.
Direct mounting may produce a stronger transducer signal and requires less mounting length than
Reflect mounting. This can be important if the liquid or pipe material exhibits high sonic attenuation,
thereby preventing operation in the Reflect configuration.
NOTE: We recommend using Direct Mount with Plastic pipes.
To select a Xdcr Mounting Mode:
To access the [Xdcr Mount Mode] option list press the <Right Arrow>.
To move the cursor to the required mounting type press the <Up/Down Arrows>.
To store selection press <ENTER>.