Transducer Problems; Clamp-On Transducer Problems - GE UTX878 Ultrasonic User Manual

March 2004

Transducer Problems

Clamp-on Transducer
Problems
6-8
Ultrasonic transducers are rugged, reliable devices. However, they
are subject to physical damage from mishandling and chemical
attack. Clamp-on transducers are also subject to installation variables
such as physical misalignment and faulty coupling to the pipe on
which they are mounted.
Because the UTX878 uses clamp-on transducers, the following list
concerns potential clamp-on problems. Contact GE Panametrics if
you cannot solve a transducer-related problem.
1. POOR COUPLING TO PIPE: Clamp-on transducers must be in
close contact with the pipe. Make sure the pipe wall is smooth and
generally free of paint. The couplant material must fill voids
between the transducer and the pipe, and must be firmly coupled
or bonded to both the pipe and the transducer. The pipe and
transducer must be clean and dry for permanent couplant, such as
grease or epoxy, to adhere properly. Enough pressure must be
applied to the transducer by its clamp to hold it firmly against the
pipe.
2. MISALIGNMENT: The transducer transmits relatively narrow
beams of ultrasound; therefore; transducer alignment is critical to
assure that the beam can travel from one transducer to the other
without undue attentuation. Be sure to exactly follow the
instructions that came with your transducers and clamping
fixtures. Also, be sure that the actual transducer spacing agrees
with the calculated spacing (S).
3. INTERNAL DAMAGE: Ultrasonic transducers consist of a
ceramic "crystal" bonded to the transducer case. The bond
between the crystal and the case may be damaged by extreme
shock and by temperature extremes. The crystal itself can also be
damaged by the same conditions. The internal wiring can be
corroded or shorted if contaminants enter the transducer housing.
4. PHYSICAL DAMAGE: Transducers may be physically damaged
by dropping them onto a hard surface or striking them against
another object.
IMPORTANT: Transducers must be replaced in pairs. Refer to
Chapter 2, Programming Site Data, to program the
new transducer data into the meter.
5. CYCLE SKIP CONDITION: A cycle skip is usually caused by a
distorted or altered signal due to poor couplant, bad pipe wall or
unusual fluid disturbances. To resolve a cycle skip, recouple both
transducers with proper couplant. Check your couplant for
temperature ranges. In addition, make sure the pipe wall is free of
paint and rust.
Contact GE Panametrics if you cannot solve a transducer-related
problem.
Error Codes and Diagnostics