The flow sensors of the SI6 series serve to monitor liquids and gases in pipes in the food and beverage industry. Thanks to a broad selection of process adapters, the sensors can be used in nearly all applications.
The robust stainless steel housing with protection rating IP 67 / IP 69K is suited for use in harsh environments. The sensors can be used at medium temperatures up to 120 °C.
The flow range and the switch points are adjusted using a pushbutton on the unit. A multicolour LED display indicates the nominal flow range and the switch point.
Electronic locking of the settings prevents unintentional maladjustment. The possibility of restoring the factory settings provides additional safety.
What Is a Hygienic Flow Meter?
A hygienic flow meter measures the flow of liquids or gases in environments requiring strict sanitary standards, such as food, beverage, pharmaceutical, and biotech processes. By combining stainless-steel wetted parts and sanitary process connections, these meters ensure cleanability and product safety—key for sensitive applications.
How Does a Hygienic Flow Meter Work?
Based on technologies like magnetic-inductive, thermal, or ultrasonic, hygienic flow meters use non-mechanical sensing to monitor flow accurately and reliably. For instance, the SM Foodmag employs magnetic-inductive measurement to track flow rate, totalised volume, flow direction, temperature, and conductivity—all transmitted digitally via IO-Link. hermal-based models like the SI series use precise heat-based detection, ideal for flow/no-flow applications, and come with hygienic process adapters.
Types of Hygienic Flow Meters
- Magnetic-inductive (SM Foodmag / SMF series):
Measure conductive media like milk, wort, or creams. Offer full digital outputs including flow, temperature, conductivity, and empty-pipe detection—all via IO-Link. - Thermal (SI series):
Ideal for detecting flow/no-flow of liquids, gases, or steam. Hygienic adapters suit sanitary requirements, and some models include LED displays for easy monitoring. - Ultrasonic (SU series):
Non-intrusive clamp-on designs accurately measure water or oil without media contact—suitable for CIP/SIP systems.
Advantages and Disadvantages
Advantages
- Hygienically designed: Sanitary fittings and smooth stainless surfaces support CIP/SIP cleaning.
- Non-mechanical sensing: No moving parts, which reduces wear and maintenance demands.
- Rich IO-Link output: Includes flow, total volume, temperature, conductivity, empty-pipe detection, and diagnostics.
- Resilient to harsh cleaning: Tested for pressure, temperature shock, vibration, and moisture—up to IP69K for washdown durability .
Considerations
- Requires IO-Link infrastructure for full benefit.
- Loop-powered models may restrict simultaneous power and signal channels.
- Thermal models require uninstall and reinstall if used for gases or steam.
Where Are They Used?
Hygienic flow meters are essential in:
- Dairies – monitoring milk, cream, pasteurised liquids.
- Breweries – tracking wort and beer flow.
- Food & beverage mixing systems – accurate dosing and cleaning.
- Pharma/CIP systems – ensuring validated flow and no contamination.
These applications benefit from hygienic design and IO-Link diagnostic capabilities that eliminate process blind spots.
How to Choose the Best Hygienic Flow Meter
- Medium type: Conductive? Go with magnetic-inductive (SM Foodmag). Flow/no-flow? Choose thermal (SI series).
- Required outputs: For flow, temperature, conductivity or empty-pipe, select IO-Link models like SM Foodmag.
- Process temperature/pressure: Ensure rating matches CIP/SIP heat and washdown pressure—IP69K is standard.
- Mounting style: Inline versions for accurate measurement; ultrasonic for clamp-on, non-invasive installs.
- Ease of setup: App-guided configuration, M12 connectors, visible LEDs and displays ease commissioning and diagnostics.
