Regarding the dielectric constant issue of guided-wave radar level gauges
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Dear seniors: As is well known, guided wave radar level gauges are used to measure liquid levels, and the dielectric constant of the medium must be ≥1.4. What happens if it is lower than that? I understand that if it is too low, the electromagnetic pulse returning from the interface has no effect; however, since the dielectric constant is below 1.4, the electromagnetic pulse cannot reach the bottom of the device and thus cannot generate a reflected pulse that returns to the signal receiver, so it is not possible to determine the liquid level. However, when the dielectric constant is high, things are different: electromagnetic pulses can be reflected smoothly from the interface and the bottom of the device back to the signal receiver. By calculating the time difference between these two reflected electromagnetic pulses, the liquid level can be determined. The above is my understanding; I’m not sure if it’s correct or not. I welcome feedback from those with more experience. Thank you
My understanding is that radar should be avoided as much as possible; in fact, it should be firmly resisted unless there are no other viable methods of measurement.