The use of hydrostatic pressure measurements can also determine fluid level within a tank.
Burkert Pressure Sensor – Basically, fluid within a tank generates a specific hydrostatic pressure based on level and fluid density.
Measuring pressure with respect to a reference pressure, usually ambient, the level is determined, assuming fluid density is known.
This method used within a pressurised vessel, using a second Burkert Pressure Sensor to measure the gauge pressure above the fluid level.
Using these two pressure measurements, it is also possible to evaluate an accurate level measurement.
Accuracy may be dependent on the precision of the pressure sensor.
Higher internal pressures within the tank increase the margin of error as well as using two sensors, also compounding the original tolerance values.
A piezo-resistive sensor filled with hydraulic fluid to provide protection for the sensor.
External pressure, sensed through the diaphragm by a change in hydraulic fluid pressure.
The sensor produces a pressure-proportional signal, converted to the conventional analogue 4-20 mA output signal.
This device, also suited to low pressure measurement, can withstand high overload factors.
A thin-film strain gauge gives precise measurements and very high burst pressure characteristics.
Also uses a thin-film Wheatstone bridge to measure changes in resistance from external pressure.
This converts a proportional measurement into an analogue output signal.
Applications involving aggressive media or higher pressures, preferable thick-film ceramic measuring cell.
The Wheatstone bridge, bonded to a ceramic diaphragm, providing greater protection and better chemical resistance.
The measuring accuracy, not as high as that of the thin-film strain gauge.