The signal transmission line failure of a thermal flowmeter can have various adverse effects on the measurement results. The following is a specific analysis:
Inaccurate measurement data
Signal attenuation: Line aging, poor contact, or interference may cause signal attenuation during transmission. This will weaken the signal received by the display instrument, resulting in measurement results that are smaller than the actual flow rate, causing measurement errors.
Signal distortion: When there is a short circuit, open circuit, or strong electromagnetic interference in the transmission line, the waveform of the signal may be distorted, causing the display instrument to be unable to correctly interpret the signal, resulting in significant deviation in the measurement results and inability to truly reflect the actual flow rate of the fluid.
Unstable measurement data
Poor contact: Loose circuit plugs, oxidized sockets, or virtual connections in the middle of the circuit can cause intermittent signal transmission. This makes the signal received by the display instrument unstable, resulting in irregular fluctuations in the measurement results and inability to provide stable and reliable flow data.
Interference fluctuation: If the transmission line is not well shielded, the surrounding electromagnetic interference will be superimposed on the signal, causing fluctuations in the signal. This fluctuation can cause the measurement results to fluctuate up and down, seriously affecting the accurate monitoring and control of flow.
No measurement data displayed
Open circuit fault: When a signal transmission line breaks, such as the line being cut off or the connector being completely disconnected, the signal from the flowmeter cannot be transmitted to the display instrument, resulting in no measurement data being displayed on the display instrument and unable to obtain flow information.
Short circuit fault: A short circuit occurs between two wires of a transmission line, which can prevent the normal transmission of signals and also cause the display instrument to display no measurement data, affecting the normal monitoring of flow.
Zero drift
Line insulation problem: The insulation performance of the line decreases, which may lead to signal leakage or external interference, causing the flowmeter to still have a certain signal input when there is no flow passing through, resulting in zero drift phenomenon, that is, the measurement result fluctuates or deviates from zero near zero flow.
Response lag
Line capacitance and inductance changes: Changes in parameters such as capacitance and inductance in the line, such as moisture and insulation aging, can cause changes in the speed and characteristics of signal transmission, resulting in signal transmission delays. This will cause the response of the measurement results to lag behind the actual changes in flow rate, making it difficult to accurately reflect the true situation of flow rate in a timely manner when the flow rate changes rapidly.
