Sensors for Ventilators
Sensirion – Your Go-to Flow Solution Provider
Sensirion is your sensor expert in the field of medical ventilation and a leading global manufacturer of flow sensors. We offer sensors for flow measurements in respiratory devices. Our flow sensor platforms SFM3xxx and SFM4xxx include sensors for inspiratory, expiratory and proximal flow measurements as well as gas mixing.
Where Do You Want to Measure Flow?
All information about inspiratory (gas mixing), expiratory and proximal flow sensing as well as the right sensors can be found below.
This includes the important documents (datasheets, application notes, engineering guide, CAD files etc.).

Why Sensirion?
The SFM3xxx and SFM4xxx platforms consist of multiple flow sensors with comprehensive capabilities for a diverse range of applications. All the sensors share the characteristics of high accuracy and robustness. The fully calibrated and temperature-compensated sensors accurately measure the flow rates of air and other gases bidirectionally. They impress with their very low pressure drop and fast signal sampling.
Your benefits at a glance:
- Fully calibrated sensors and flow modules, no need for re-calibration
- Bi-directional capability
- No drift over time
- Demonstrated long-term repeatability and stability
- Multi-gas calibration
- Highest accuracy in market at low flows
- Fastest integration time with broadest flow portfolio
Inspiratory Flow Measurement
Sensirion's inspiratory flow sensors are typically used inside the ventilator to measure the individual air/O2/heliox gas lines as well as the total flow of the mixed gas before delivery to the patient. Our sensor platform includes sensors for flow measurement at ambient pressures (SFM3xxx series) and sensors for placement on the high-pressure side upstream of the proportional valves (SFM4xxx).
Selected Reference Projects
Expiratory Flow Measurement
Sensirion’s expiratory flow sensors offer outstanding performance at low flow rates and very low pressure drops, as required in the expiratory limb. Thanks to their robustness, the sensors can be treated in an autoclave, making them easy to sterilize and thus reusable. As expiratory flow measurements work with humid respired air, a special, externally controllable heating element has been integrated that helps prevent condensation inside the flow sensor.
Selected Reference Projects
Flow Sensors for Expiratory
Humid patient gas | Dry, filtered gas |
---|---|
SFM3200-AW | SFM3200 |
Proximal Flow Measurement
Sensirion's proximal flow sensors are designed specifically for adults or neonates with integrated fully bidirectional flow calibrations and an on-board heater to combat humid breathing environments without jeopardizing flow signal integrity. Both come in re-usable and single-use variants.
Selected Reference Projects
Proximal Flow Sensors
Adult | Pediatric | |
---|---|---|
Single-use | SFM3300-D | SFM3400-D |
Re-usable (autoclavable & washable) | SFM3300-AW | SFM3400-AW |
Humidity Measurement
When humidity needs to be measured, Sensirion’s latest generation SHT4x temperature and humidity sensor platform is the best choice. Its unique condensation resistance in particular enables usage both outside and within patient circuits.
Sensor Evaluation
For quick and easy testing, a ready-to-use kit is available for each flow sensor. Together with the provided software and the engineering guide, it enables a plug and play connection between the sensor and a PC. More information about the evaluation kits can be found here.
The evaluation kits can be ordered directly from our distributors.

Important Documents
Datasheets
- Datasheet SFM3000
- Datasheet SFM3003 (coming soon)
- Datasheet SFM3013 (coming soon)
- Datasheet SFM3019
- Datasheet SFM3020
- Datasheet SFM3100
- Datasheet SFM3119 (coming soon)
- Datasheet SFM3200
- Datasheet SFM3200-AW
- Datasheet SFM3300
- Datasheet SFM3400
- Datasheet SFM4200
- Datasheet SFM4300 (coming soon)
Application Notes
An overview to which sensors each application note applies can be found in the AppNote SFM-01 "Engineering Guidelines for Mass Flow Meters" on page 14 (section 6.2, Table 5).
Public Application Notes
- SFM-04 CRC Checksum
- SFM-05 I2C Functional Description
- SFM-10 Handling Instructions
- SFM-21 Cleaning Methods
- SFM-22 Clip-On Cap/Cable Evaluation Kit
- SFM-25 Reference and Flow Conversions
- SFM-26 Reference and Flow Conversions Calculator
- SFM-27 High Humidity Applications
Confidential Application Notes
- SFM-07 Response Time Comparison
- SFM-08 Temperature Effects
- SFM-23 Effects of Humidity and Gas Mixtures
In order to request a “confidential application note”, please fill out the following form. After checking your eligibility and approving, we will directly send you the requested application notes. We are often very fast, but please allow up to 3 days for a response before re-contacting us.
Application Notes with Higher Confidentiality Level
- SFM-31 Wetted Material List for Proximal Sensors
- SFM-32 Wetted Material List for Inspiratory Sensors
Sharing the wetted material lists requires to have a valid standard mutual non-disclosure agreement in place. Please carefully read, fill completely and return the NDA to medicalsensirioncom in order to start the NDA process.
Please note that the general sensor materials ARE DISCLOSED in the respective datasheets of the sensors. The wetted material lists are typically only required once a project has been started and when working on certification aspects. Hence we reserve the right to share the wetted material lists at that point in time and when all requirements are met.
CAD Step-Files
Please note: The inside of the flow sensor has been simplified or omitted in the CAD drawing.
- STEP File SFM3000
- STEP File SFM3003, 3019, 3020
- STEP File SFM3100
- STEP File SFM3119
- STEP File SFM3200
- STEP File SFM3200-AW
- STEP File SFM3300-AW
- STEP File SFM3300-D
- STEP File SFM3400-AW
- STEP File SFM3400-D
- STEP File SFM4100 Downmount
- STEP File SFM4100 Straight
- STEP File SFM4200
- STEP File SFM4300
- STEP File SFM Cap for AW/D Type Sensors
Other Documents
Our Expert Know-how
Flow Sensor Solutions in Modern Medical Ventilators
The use and spread of ventilators will continue to grow strongly in the future due to the increasing number of lung diseases. Modern ventilators place ever-growing demands on sensors in order to set the focus on the patients and their therapy. Sensirion's CMOSens® Technology has established a new generation of flow sensors that have proven their reliability millions of times in the field of CPAP devices. This technological advantage will enable manufacturers to realize the next quantum leaps in ventilation. Read the complete specialist article here.
These specialist articles might be of interest to you:
"Sensirion was the ideal partner. Their expertise and support accelerated our development phase and the robust design of the sensors contributes to the success of the MEDUMAT ventilator."
Andreas Sommer, Head of Systems Engineering at WEINMANN
"Sensirion’s initiative taken to rapidly scale their flow sensor manufacturing with a new product allowed our team to develop the system in under two months with future proof technology."
John Walmsley, Executive VP of Strategic Relationships at StarFish Med