01
Hydrostatic level measurement
Pressure at the bottom of the liquid column provides level information and is largely unaffected by foam at the top surface.
ifm · Hygienic pressure
ifm PI Hygienic Pressure Sensors
Flush sanitary pressure sensing for food, beverage and hygienic-process applications where tank level, line pressure, pressure spikes and cleanability matter. The current PI1 generation combines a ceramic-capacitive measuring cell, local display and IO-Link data with hygienic process-adapter options.
PI1 sanitaryCeramic capacitiveFlush process faceIO-LinkPressure + temperature dataHydrostatic level
PI1 rangeLow mbar to 40 barPlus higher-pressure G1 variants
CellCeramic-capacitiveDirect flush pressure measurement
Primary applicationsPressure + levelTanks and sanitary process lines
Digital routeIO-LinkHigh-resolution pressure and additional data
Hygienic process applications
One sensor platform for line pressure and hydrostatic tank level
PI1 is particularly useful where hygienic process design and direct pressure measurement must coexist with pressure spikes, foam or rapidly changing process conditions.
02
Line pressure
Monitor product, water and CIP-related line pressure with a local display and digital process data.
03
Pressure spikes / water hammer
The supported ceramic cell architecture is designed for high overload robustness in processes with fast valves and pressure surges.
04
Density-related measurement
Paired pressure points can support density-related calculations in appropriate tank architectures.
Measurement principle
A flush ceramic diaphragm measures pressure directly—without fill fluid behind a metal diaphragm
The alumina ceramic measuring cell acts as a capacitor. Pressure deflects the ceramic diaphragm by a tiny amount, changing capacitance that the electronics convert into a pressure value.
Direct pressure measurementThe ceramic cell does not depend on the fill-fluid arrangement used by conventional diaphragm-seal designs.
Flush process faceDesigned to minimise dead space and reduce areas where deposits can build.
Overpressure robustnessCeramic construction and support help tolerate pressure peaks common in hygienic lines.
Diagnostic confidenceCurrent PI1 positioning includes monitoring of measuring-cell condition and high-resolution digital pressure data.
PI1 selection
Select pressure range first, then process connection
| Aseptoflex Vario | G1 sealing cone | Measuring range | Typical selection use |
|---|---|---|---|
| PI1703 | PI1803 | -1…25 bar | Higher line pressure |
| PI1704 | PI1804 | -1…10 bar | General process pressure |
| PI1705 | PI1805 | -1…4 bar | Lower line / tank pressure |
| PI1706 | PI1806 | -0.124…2.5 bar | Low pressure / hydrostatic level |
| PI1707 | PI1807 | -50…1000 mbar | Tank-level / low-pressure range |
| PI1708 | PI1808 | -12.5…250 mbar | Very low hydrostatic pressure |
| PI1709 | PI1809 | -1000…1000 mbar | Vacuum / bidirectional relative pressure |
| PI1743 | PI1843 | -1…40 bar | Higher-pressure sanitary application |
Connection style is part of the hygienic design. Do not quote the range alone. Confirm the required process adapter, vessel geometry, seal material, vent arrangement and relevant hygienic approvals for the exact order number.
Digital process value
IO-Link adds high-resolution pressure data, temperature and device diagnostics
For low hydrostatic ranges, digital resolution matters because relatively small pressure changes represent meaningful level changes. The current PI1 family exposes high-resolution pressure values and additional process / diagnostic data through IO-Link.
High-resolution digital value
Avoid analogue A/D conversion losses when the PLC architecture supports IO-Link.
Additional process information
Current PI1 process data includes temperature information useful for diagnostics and compensation context.
Central device setup
Store settings and support device replacement through the IO-Link architecture.
Sensor condition visibility
Use current device diagnostic information to increase confidence in critical process measurements.
Installation and adapters
The process connection and weld adapter are part of the measurement quality
Aseptoflex Vario provides installation flexibility
The PI1 Aseptoflex route uses adapters for common sanitary connections. Selection must consider drainage, tank wall shape, weld quality and seal compatibility—not only thread size.
Common adaptersTri-clamp and weld adapters are available for the PI1 architecture
Seal optionsEPDM, FKM and PEEK routes are available as specified accessories
VentGauge-pressure devices require correct atmospheric venting; protect the vent in demanding washdown environments
WeldingUse the specified weld adapter / mandrel approach to control distortion
Tank geometryAdapter shape and sensing-face position affect drainage and cleanability
Requirement capture
Inputs required to select the PI sensor and adapter
FunctionLine pressure, vacuum, hydrostatic level or pressurised tank.
RangeMinimum / normal / maximum pressure or required level span.
MediumProduct, water, CIP fluid and cleaning chemistry.
TemperatureProduct and cleaning temperatures, including thermal cycling.
Process connectionTri-clamp, weld fitting, Aseptoflex Vario or G1 sealing cone.
OutputSwitching, analogue and/or IO-Link requirement.