Liquid Flow Meter SLI
For Life Science and Automation
Designed for integration in demanding flow control systems, the SLI liquid flow meter series is a high precision solution for low flow rates of liquids based on water or hydrocarbons (alcohols, solvents, oil, fuel, adhesives). Sensirion’s modular approach, which allows the liquid flow meter to be combined with several interface cables, ensures an optimal match and simplifies the integration of a liquid flow meter into a fluidic system.
The short response time and high precision of the SLI liquid flow meter allow accurate monitoring of highly dynamic processes such as fast dosing operations. As with all other Sensirion liquid flow meters, this reliable device works without any moving parts, measuring through the wall of a straight flow path. Ultimate media compatibility of all wetted parts is ensured by the exclusive use of highly inert materials (glass, PEEK and flouropolymer sealing). The robust IP65 protected housing in a compact form makes the SLI flow meter the first choice for the measurement of low flow rates from single-digit microliters to several milliliters per minute in demanding applications in the life sciences and industrial automation.
The SLI liquid flow meter in combination with one of the SCC1 sensor cables offers a modular solution with a suitable electrical interface for almost any environment:
- The SCC1-USB sensor cable provides a plug-and-play connection to a PC for operation with Sensirion’s viewer software or user-built programs for laboratory and desktop applications.
- The SCC1-RS485 sensor cable featuring a stable RS485 interface and including advanced functionality such as dispense volume totalizer, automatic dispense detection, and data buffer for asynchronous read-out is designed for demanding industrial automation environments.
- The SCC1-Analog sensor cable and SCC1-Current 0-20mA sensor cables allow simple and quick readings or integration into generic controller systems without programming. In addition to a 0-10 V analog voltage output, the cable provides a configurable digital (high/low) output that can be programmed to act as a flow switch or pulse output.
Features
- Three sensor versions cover different flow ranges from microliters per minute to milliliters per minute
- Maximum flow rate for water-based liquids: 10 ml/min
- Maximum flow rate for hydrocarbons: 80 ml/min
- Repeatability: below 1% of the measured value
- Highest sensitivity down to <1 µl/min
- Fast response time down to 40 ms
- RS485, USB or 0-10 V analog voltage output
- Inert wetted materials: glass, PEEK, and fluoropolymer
- Maximum recommended operating pressure: up to 50 bar depending on flow range
- IP65 water and dust protection
Applications
- General process monitoring
- Pump control
- Fuel flow monitoring
- Lubricants dosage monitoring
- Monitoring of spray coating
- Conformal coating
- Leakage detection
Sensor Evaluation
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 SLI evaluation kit can be ordered from our distributors.
Overview of SLI-xxxx Versions
Model | Wetted materials | Electrical interface | Flow range (H20) and full scale flow rate (µl/min) | Evaluation kit | Datasheet |
---|---|---|---|---|---|
SLI-0430 | Quartz Glass (Fused Silica), PEEK | 4-pin M8 circular standard connector, I2C Designed for use with the SCC1 sensor cables | 80 | Liquid Flow Meter Kit for SLx Series link | Datasheet |
SLI-1000 | Borosilicate Glass 3.3, PEEK, FEP | 4-pin M8 circular standard connector, I2C Designed for use with the SCC1 sensor cables | 1000 | Liquid Flow Meter Kit for SLx Series link | Datasheet |
SLI-2000 | Borosilicate Glass 3.3, PEEK, FEP | 4-pin M8 circular standard connector, I2C Designed for use with the SCC1 sensor cables | 5000* | Liquid Flow Meter Kit for SLx Series link | Datasheet |
*Extended range up to 10000 µl/min
If your product is not here please check our selection guide.
Software and Driver
Important Documents
- Datasheet SLI
- Datasheet SCC1- Analog Sensor Cable
- Datasheet SCC1- RS485 Sensor Cable
- Datasheet SCC1 - 4-20 mA (0-20 mA) Analog sensor cable
- Quick Start Guide Liquid Flow Meter Kit
- Application Note Chemical Resistance
- Application Note Cleaning and Clean Handling
- Application Note Sensor Ports and Tubing Connections
- Application Note for Dispense Volume or Flow Rate Correction
(if you are working with different media)
Useful Information
General Information
- The SLI sensors rely 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 SLI Liquid Flow Sensors are 100% factory calibrated, for H2O However, it can also be used to measure fluids different from H2O in terms of thermodynamic properties by following the instructions in the Application Note for Dispense Volume or Flow Rate Correction.
- Please see the SLI datasheet for the specific pin-out of the sensor.
- There are additional operating guidelines and application notes on request (e.g. on I2C, installation guidelines, ...).
Handling Instructions
- 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.
- Start testing the sensor horizontally mounted. This is the orientation it has been calibrated in.
- The sensor is susceptible to ESD damages, especially when touching the connector pins. During handling and testing, suitable ESD precautions must be taken.
Cleaning Instructions: - 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 Note Cleaning and Clean Handling.
Liquid Flow Meter Kits
For quick and easy measurements with all SLI, SLS, SLG, or SLQ liquid flow meters, the respective flow meter kits can be ordered from our distribution partners. The flow meter kit provides everything you need for plug-and-play setup and is the first choice for initial evaluation of our technology in your application.

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