Use of 41X Hydrostatic Pressure Transducers as Hydrolevels

There is a need for accurate and stable measurements of the tilt of hydraulic structures. Continuous measurements and analysis help to understand the nature of the phenomenon and predict the onset of an undesirable event. Manual measurements are becoming a thing of the past, as the human factor inevitably arises, and additionally, the work of extra personnel must be paid for.

The most popular tool for online monitoring of these processes are optical hydrolevels, but the cost of this equipment is extremely high, and questions often arise regarding the stability of measurements. Optics require constant cleaning and adjustment, and sometimes this can cause serious deviations from the actual parameters needed for analysis.

Today, we offer an economical solution that could be used alongside the main measurement system for control purposes. Thus, we will receive additional information and dependencies, which will allow us to cross-check our main results.

To measure the tilt of structures, we propose installing two 41X hydrostatic pressure sensors manufactured by the Swiss company Keller AG, placing them at different ends of the object. Using these sensors, we measure the difference in level at two points, and based on these values, we can judge the tilt of our structure. Our hydrostatic pressure sensors use a highly stable capacitive ceramic cell, which is housed in a case along with the most advanced electronics for signal conversion, temperature compensation, and ensuring maximum measurement accuracy.

An undeniable advantage of the system using two hydrostatic pressure sensors compared to any optical methods is its low cost. In addition, Keller pressure sensors have already proven themselves worldwide as stable and reliable instruments. According to statistics from 2003 – 2005, the mean time between failures was 973,486 hours for all Keller instruments, calculated based on the number of warranty returns. This significantly exceeds similar parameters for optical instruments.

Additional advantages of Keller hydrostatic pressure sensors. The 41X pressure sensors have an IP65 protection class, thus they remain reliably protected from moisture and dust.

Information from the sensors is transmitted via a digital output interface RS485 Modbus RTU; all protocols are open, and the sensors can be easily integrated into your system.

The 41X pressure sensors have a minimum measurement range of 0…30 mbar, which corresponds to a scale of 0…300 mm of water column.

The typical total error of the sensors in the range of 10…50°C is 0.1% FSO. It is worth noting separately that this is the total error, not the basic specified error, which is determined only at a fixed temperature. Here we are talking about the error that includes all factors over the entire range of pressures and temperatures. Thus, we can obtain liquid level values with an accuracy of 0.3 mm!

At the same time, the resolution of our sensors, which allows judging the dynamics of events, is 1 µbar or 0.01 mmH2O!

Together with the sensors, we supply convenient software that not only allows displaying and recording data on pressure and temperature but also allows setting measurement units and, most importantly, allows zero and slope calibration. This function opens up prospects for working with these instruments for 10 years and more. Based on periodic calibration results, after performing the necessary manipulations, we will again have an instrument with high accuracy.

For additional information, please contact our specialists!

Dear colleagues and specialists, you may also be interested in our article on groundwater level monitoring.