Liquid Flow Sensor SLF3x
Made to Measure: The Next Level in Liquid Flow Sensing
The SLF3x series is the next generation of Sensirion’s liquid flow sensors. By combining Sensirion’s excellent 20-year track record in low and lowest flow rate sensing with a radically optimized mechanical design, the SLF3x takes the well-established functionality to the next level in price-performance ratio. The sensor provides maximum safety, stability and long-term reliability and allows monitoring the entire system operation and detecting common failure modes for a wide range of applications, including the fields of diagnostics, analytical instruments and life sciences.
The liquid flow sensors of the SLF3x series are based on Sensirion’s proven CMOSens® Technology and optimize costs by simplifying the design without sacrificing the easy fluidic, electrical and mechanical connections. The straight and unobstructed flow channel has no moving parts; inert wetted materials provide outstanding chemical resistance and excellent media compatibility.
The SLF3x enables applications in the fields of diagnostics, analytical instruments and life sciences to reach unparalleled fluid control, system reliability and thus new heights in performance and end-user satisfaction. Its compact form factor and cost-effective design permit system designs with one or more sensors that were previously unfeasible.
The SLF3x Series
For quick and easy testing, a ready-to-use kit is available. Together with the provided software, it enables a plug and play connection of the sensor to a PC. The SLF3x evaluation kit can be ordered from our distributors.
- Highly integrated: Linearized, temperature-compensated and fully calibrated digital output signal (I2C) from a single chip
- Calibrated for water and IPA up to ± 40 ml /min (SLF3S-1300F) or ± 2000 µl/min (SLF3S-0600F)
- Turn down ratio 200:1 or better
- High speed measurement: Response time below 20 ms
- Bidirectional measurement and real time failure detection
- Easy fluidic and electrical integration via ¼″-28 flat bottom ports and a standard connector
- Straight, unobstructed flow channel without moving parts
- Media isolated sensing principle: no direct sensor contact with the fluid
- Compact and light-weight form factor
- Chemically resistant wetted materials
- Failure detection and volume confirmation for diagnostics, cell analysis, and analytical instruments
- Process control and monitoring for coating, additive, and reagent dispensing systems
Software and Drivers
- Datasheet SLF3S-1300F
- Datasheet SLF3S-0600F (Preliminary)
- Calibration Certification Liquid Flow Sensor SLF3x
- Quick Start Guide for Liquid Flow Meter Kits
- Operating Guidelines for SLF3x Evaluation Kits
- Application Note Cleaning and Clean Handling
- Application Note Sensor Ports und Tubing Connections
- Application Note for Dispense Volume or Flow Rate Correction
(if you are working with different media)
- The SLF3x sensor relies on a thermal measurement principle. Therefore, it is sensitive to the thermodynamic properties of the fluid. For details see CMOSens® for Liquid Flow Meters.
- The SLF3x Liquid Flow Sensor is 100% factory calibrated, for H2O and IPA. However, it can also be used to measure fluids different from H2O and IPA in terms of thermodynamic properties by choosing the calibration most closely matching your fluid and following the instructions in the Application Note for Dispense Volume or Flow Rate Correction.
- Please see the sensor's datasheet for the specific pin-out of the sensor.
- There are additional operating guidelines and application notes available which will be send to you on request (e.g. on I2C, installation guidelines, ...).
- Follow the instructions in the Quick Start Guide for Liquid Flow Meter Kits to use the SLF3x sensor together with Sensirion’s Sensor Viewer Software. During start-up of the software, select „Liquid Flow Sensor (SF06 Chip)“ for the SLF3x. When choosing the COM Port Settings to start the Sensor Viewer Software select a COM port such that “USB Serial Port” appears next to your chosen COM port setting. It is a PC dependent setting and no general one.
- The maximum flow range of the sensor is specified such to achieve a laminar flow at the position of the micro thermal chip. Use tubing and fluidic connection material with at least the same inner diameter as the one of the flow channel. Sensirion recommends min. 2 mm ID tubing for the SLF3S-1300F and min. 1.0mm ID tubing for the SLF3S-0600.
- Start testing the sensor horizontally mounted. This is the orientation it has been calibrated in. Use the SLF3x mounting clamp for fixation of the sensor.
- The sensor is susceptible to ESD damages, especially when touching the connector pins. During handling and testing, suitable ESD precautions must be taken.
- After ending your measurements, make sure to always store the sensor's flow channel clean and dry in order to maintain a high level of performance. This avoids the growth of a biofilm or other deposits which will impact the sensor's reading the next time. To do so, always drain the fluid, flush with a suitable cleaning agent and blow out with air or allow to air dry.
- For details please see the Application Notes Cleaning and Clean Handling and Biofilm.
Specialist Article: Autonomous Science
How developments in the automotive industry can predict the future of chromatography
How developments in the automotive industry can predict the futurSince the invention of the car in 1885, leaps in sensor technology, safety and automation have limited the technical interaction of the driver with the car. A similar trend is revolutionizing chromatography applications. Smarter systems, machine learning and ever-increasing amounts of data create new possibilities to automate, reduce unplanned downtime and predict maintenance schedules, thus widening the customer base to include a wider spectrum of professionals, not just specifically trained scientists.
A large portion of these developments are enabled through smart sensor solutions, where Sensirion is a valued partner for life science, diagnostic and analytical applications. Read the complete specialist article.
Closed loop constant flow rate flow source for high precision applications
In a typical lab environment, microfluidic experiments can often rely on external sources like pressurized air to drive media through the experiment. TTP Ventus manufactures the Disc Pump™, a small air pump, that can be used to build independent or even portable pressure driven flow sources for microfluidic applications. The advantage of a pressure driven flow source are the stable and non-pulsatile flow rates created over a large dynamic range. In order to leverage the full potential of such a flow source, the SLF3S-0600F liquid flow sensor for example can be used to create a small and highly integrated closed feedback loop system. By including the real time flow rate reading of the liquid flow sensor, the pump controller can drive the pump in exactly the right way to create the desired flow rates. Both, single and permanent use designs can be achieved by this approach.