Within the linear range of a liquid level sensor, higher sensitivity is generally desirable. This is because only with high sensitivity can the output signal value corresponding to the change in the measured quantity be relatively large, which is beneficial for signal processing.
However, it's important to note that while sensors are highly sensitive, external noise unrelated to the measurement can easily get in and be amplified by the amplification system, affecting measurement accuracy. Therefore, the sensor itself should have a high signal-to-noise ratio to minimize interference signals introduced from the outside.
Sensor sensitivity is directional. When the measured quantity is a single vector and its directionality is critical, a sensor with low sensitivity in other directions should be selected; if the measured quantity is a multi-dimensional vector, the lower the cross-sensitivity of the sensor, the better.
(1) The physical properties are non-uniform and variable.
If the temperature inhomogeneity between the upper and lower liquid layers is not considered, the density can be assumed to be uniform, and the weight can be easily calculated from the volume. However, in large containers, liquid level sensors often exhibit non-uniformity in the physical quantities of the measured medium, such as temperature, density, and viscosity, which may change with time and temperature, causing measurement errors.
(2) The liquid surface is uneven.
For liquids with good flowability, the liquid surface is horizontal. Therefore, except for capacitive level gauges that use the vessel wall as an electrode, general level gauges only have requirements on the installation height and can be installed at any location at the same height. Ideally, the liquid surface is a regular surface, but when materials flow in and out, there will be waves, or the liquid being measured may boil, foam, or have suspended matter on the surface during the production process, resulting in an uneven liquid surface.
(3) Special circumstances.
Liquid level sensor containers often contain high temperatures and pressures, or have very high liquid viscosity, or contain a large amount of impurities or suspended matter, which can adversely affect the measurement.
