Chapter 9. Diagnostics and Troubleshooting

9.4.1 Wetted Transducer Problems (cont.)

4.PHYSICAL DAMAGE

Transducers may be physically damaged by dropping them onto a hard surface or striking them against another object. Usually the connector on the transducer is the part that is damaged, as it is the most fragile. Minor damage may be repaired by carefully bending the connector back into shape. If the connector cannot be repaired, replace the transducers. Note that transducers must be replaced in pairs. Before replacement, make sure that the transducer number in the programmed parameters is the one engraved on the new transducers (see Chapter 3, Programming Site Data).

9.4.2 Clamp-on Transducer Problems

1.POOR COUPLING TO PIPE

Clamp-on transducers must be in intimate contact with the pipe. The pipe wall must be 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, and therefore transducer alignment is critical to assure that the beam can travel from one transducer to the other without undue attenuation. Be sure to exactly follow the instructions that came with your transducers and clamping fixtures. Also, be sure that the 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.

Transport® Model PT878 Portable Liquid Flowmeter User’s Manual

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GE PT878 user manual Clamp-on Transducer Problems, Physical Damage
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PT878 specifications

The GE PT878 is a state-of-the-art portable ultrasonic flow meter designed for the precise measurement of liquid flow in various applications. As part of General Electric’s renowned instrumentation lineup, the PT878 combines innovative technology with user-friendly features, making it an invaluable tool for engineers, technicians, and plant operators.

One of the standout characteristics of the PT878 is its non-invasive measurement capability. The meter utilizes clamp-on transducer technology, allowing it to be installed on the exterior of the pipe, eliminating the need for invasive procedures which can disrupt the system or require pipe cutting. This non-contact approach not only simplifies installation but also enhances the device’s versatility, as it can be applied to a wide range of pipe sizes and materials.

The PT878 leverages advanced digital signal processing and sophisticated algorithms to provide accurate and reliable flow measurements. It operates using the time-of-flight method, whereby ultrasonic signals are sent and received through the fluid in the pipeline to determine the flow rate. This technology allows for remarkable precision, ensuring that operational efficiency can be maintained.

Moreover, the PT878 is equipped with features such as a bright, easy-to-read display, intuitive navigation, and robustness against harsh environmental conditions. Its compact and lightweight design enhances portability, making it suitable for field applications. The meter operates on battery power, providing a long-lasting solution for remote monitoring and temporary installations.

Another impressive aspect of the PT878 is its ability to measure not only water but also a variety of liquids, from hydrocarbons to chemicals. It supports multiple measurement modes, including volumetric flow and velocity, offering a level of flexibility that caters to diverse industrial needs.

In addition to flow measurement, the PT878 offers data logging capabilities, allowing users to store and analyze flow data over time. This function is vital for understanding trends, diagnosing issues, and optimizing system performance. Users can easily transfer data to computers for comprehensive analysis, enhancing operational insights.

With its combination of innovative technology, user-friendliness, and robust measurements, the GE PT878 ultrasonic flow meter stands out as a comprehensive solution for industries requiring reliable liquid flow measurement. Whether in a manufacturing plant, a water treatment facility, or any application requiring fluid monitoring, the PT878 delivers exceptional performance and accuracy.
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