GE PanaFlow XMT1000 User Manual page 40

Chapter 3. Error Codes and Troubleshooting
3.2.2b Pipe Problems
Pipe-related problems may result either from a failure to observe the installation instructions, as described in
Chapter 1, Installation, or from improper programming of the meter (see Chapter 2, Programming, for details). By far,
the most common pipe problems are the following:
•
The collection of material at the transducer location(s). Accumulated debris at the transducer location(s)
will interfere with transmission of the ultrasound signals. As a result, accurate flow rate measurements are not
possible. Realignment of the flowcell or transducers often cures such problems, and in some cases, transducers
that protrude into the flow stream may be used. Refer to Chapter 1, Installation, for more details on proper
installation practices.
•
Inaccurate pipe measurements. The accuracy of the flow rate measurements is no better than the accuracy
of the programmed pipe dimensions. For a flowcell supplied by GE, the correct data will be included in the
documentation. For other flowcells, measure the pipe wall thickness and diameter with the same accuracy
desired in the flow rate readings. Also, check the pipe for dents, eccentricity, weld deformity, straightness and
other factors that may cause inaccurate readings. Refer to Chapter 2, Programming, for instructions on
programming the pipe data.
In addition to the actual pipe dimensions, the path length (P) and the axial dimension (L), based on the actual
transducer mounting locations, must be accurately programmed into the flow meter. For a GE flowcell, this
data will be included with the documentation for the system. If the transducers are mounted onto an existing
pipe, these dimensions must be precisely measured.
•
The inside of the pipe or flowcell must be relatively clean. Excessive build up of scale, rust or debris will
interfere with flow measurement. Generally, a thin coating or a solid well-adhered build up on the pipe wall
will not cause problems. Loose scale and thick coatings (such as tar or oil) will interfere with ultrasound
transmission and may result in incorrect or unreliable measurements.
28 PanaFlow™ XMT1000 User's Manual