For years the ifm pressure sensors of the PI series have proven their worth in the food and beverage industry. But even what is successful can be improved. Pressure changes can now be visualised via IO-Link in high resolution with approximately 20,000 steps. This is an enormous benefit, especially for hydrostatic level measurement with head pressure: in such applications, the sensor must be designed for a larger measuring range in order to withstand the additional head pressure. With conventional sensors, a larger measuring range reduces the resolution of the pressure detection this problem no longer exists with the PI.
Another advantage: the sensor also detects the medium temperature and transmits it via IO-Link. This means that it is no longer necessary to set up an additional temperature measuring point.
The pressure sensors of the new PI1 series are ideally suited for pressure measurement in tanks and pipes in food production for example in dairies, breweries and many other applications where liquids are used.
Determining the level in tanks with foaming media is a very challenging application. Most top-down measurements rely on a stable media surface to achieve reliable measurements. In addition, foam can affect the signal strength or cause inaccurate measurements.
The detection of hydrostatic pressure is ideal in such applications as the foam on the medium has little to no influence on the corresponding level measurement. This avoids incorrect measurements and signal losses and increases the performance and availability of the machine.
A customer of ifm in the food industry uses the PI1 to monitor the pressure in pipes. Here, the sensor is ideally suited with its high resolution and the clear presentation of the process value via the display.
Another advantage is the ceramic measuring cell used, which easily withstands pressure peaks. Potential product contamination that can occur due to leakage of the diaphragm liquid is also eliminated by the ceramic measuring cell.
Processes in fermentation tanks tend to leave residues. To remove these residues, spray balls are often used in addition to the conventional CIP process to clean the inside of the tank with high pressure.
The PI1 series pressure sensor can withstand the direct high-pressure jet of water nozzles and spray balls thanks to its ceramic capacitive measuring cell. It is much harder and more stable than conventional metal diaphragms, which can easily be deformed and permanently damaged in these applications.
The new pressure sensors, which are available with different measuring ranges from vacuum to 100 bar, communicate via IO-Link 1.1 and offer a resolution of about 20,000 steps. This is especially important for applications where differential pressures are measured and thus only a small part of the measuring range can be used. Temperature compensation has also been improved in the new series.
Even seemingly small improvements to the design of a sensor can have a big impact in the application. For example, the vent hole on the new pressure sensor has been offset by 90° and is now located on the side when mounted conventionally. This prevents condensate, for example, from collecting on the membrane of the vent hole and causing soiling or impairing the function. The PI has also been optimised in terms of user-friendliness: the new operating concept with three pushbuttons makes parameter setting much more convenient and thus also faster.