AT600 User’s Manual 75
Chapter 4. Error Codes and Troubleshooting
4.2 Diagnostics
4.2.1 Introduction
This section explains how to troubleshoot the AT600 if problems arise with the electronics enclosure, the flowcell, or
the transducers. Indications of a possible problem include:
• Display of an error message on the LCD display screen, Vitality PC software, or HART.
• Erratic flow readings
• Readings of doubtful accuracy (i.e., readings that are not consistent with readings from another flow measuring
device connected to the same process).
If any of the above conditions occurs, proceed with the instructions presented in this chapter.
4.2.2 Flowcell Problems
If preliminary troubleshooting with the Error Code indicates a possible flowcell problem, proceed with this section.
Flowcell problems fall into two categories: fluid problems or pipe problems. Read the following sections carefully to
determine if the problem is indeed related to the flowcell. If the instructions in this section fail to resolve the problem,
contact GE for assistance.
4.2.2a Fluid Problems
Most fluid-related problems result from a failure to observe the flowmeter system installation instructions. Refer to
Chapter 2, Installation, to correct any installation problems.
If the physical installation of the system meets the recommended specifications, it is possible that the fluid itself may
be preventing accurate flow rate measurements. The fluid being measured must meet the following requirements:
1. The fluid must be homogeneous, single-phase, relatively clean and flowing steadily.
Although a low level of entrained particles may have little effect on the operation of the AT600, excessive amounts
of solid or gas particles will absorb or disperse the ultrasound signals. This interference with the ultrasound
transmissions through the fluid will cause inaccurate flow rate measurements. In addition, temperature gradients in
the fluid flow may result in erratic or inaccurate flow rate readings.
2. The fluid must not cavitate near the flowcell.
Fluids with a high vapor pressure may cavitate near or in the flowcell. This causes problems resulting from gas
bubbles in the fluid. Cavitation can usually be controlled through proper installation design.
3. The fluid must not excessively attenuate ultrasound signals.
Some fluids, particularly those that are very viscous, readily absorb ultrasound energy. In such a case, an error code
message will appear on the display screen to indicate that the ultrasonic signal strength is insufficient for reliable
measurements.
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