Panametrics DigitalFlow XGF868i, Руководство по обслуживанию

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Chapter 3. Diagnostics
20 DigitalFlow™ XGF868i Service Manual
transducer mounting locations, must be accurately programmed into the flowmeter. For a Panametrics 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. See Appendix C, Measuring P and L Dimensions , of the
Startup Guide for a thorough discussion of this topic.
3. Signal strength above 75.
The XGF868i is supplied with a signal preamplifier. However, this amplifier may not be necessary for high pressure
applications. If the meter has a signal strength above 75, bypass the preamp and connect the coax cable
directly to the transducers.
3.4 Transducer Problems
Ultrasonic transducers are rugged, reliable devices. However, they are subject to physical damage from mishandling
and chemical attack. The most common transducer problems are listed below:
1. LEAKS: Leaks may occur around the transducer and/or the flowcell fittings. Repair such leaks immediately. If the
leaking gas is corrosive, carefully check the transducer and cables for damage, after the leak has been repaired.
2. CORROSION DAMAGE: If the transducer material was not properly chosen for the intended application, the
transducers may suffer corrosion damage. The damage usually occurs either at the electrical connector or on
the transducer face. If corrosion is suspected, remove the transducer from the flowcell and carefully inspect the
electrical connector and the transducer face for roughness and/or pitting. Any transducer damaged in this
manner must be replaced. Contact Panametrics for information on transducers in materials suitable for the
application.
3. INTERNAL DAMAGE: An ultrasonic transducer consists of a ceramic crystal bonded to the transducer case. The
bond between the crystal and the case or the crystal itself may be damaged by extreme mechanical shock
and/or temperature extremes. Also, 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. The transducer connector is the most fragile part and is most subject to damage.
Minor damage may be repaired by carefully bending the connector back into shape. If the connector can not be
repaired, the transducer must be replaced.
IMPORTANT: Transducers must be replaced in pairs. Refer to Chapter 2, Initial Setup, of the Startup Guide to program
the new transducer data into the meter.
If the instructions in this section fail to resolve the problem, contact Panametrics for assistance.