SFM3100 Low Pressure Drop Analog Flow Meter
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Data Sheet - SFM3100 Low Pressure Drop Analog Flow Meter ■ Analog output ■ Compact design ■ Flow range: -24 ... 240 slm ■ Direct gas temperature measurement ■ Fully calibrated & temperature compensated ■ Very fast response time Product Summary The SFM3100 sensor is Sensirion's flow meter designed for the mass flow measurement in ventilators. It measures the flow rate of air, oxygen and non-aggressive gases with superb accuracy. A special design of the flow channel results in the very low pressure drop through the flow body of the sensor making it extremely suitable for medical ventilation and respiratory applications. The SFM3100 operates from a 5 V supply voltage and features an analog interface. The signal is internally processed and temperature compensated. The outstanding performance of these sensors is based on Sensirion's patented CMOSens® sensor technology, which combines a thermal sensor element, signal processing and digital calibration on a single microchip. This assures very fast signal processing. An additional temperature sensor provides a highly accurate temperature measurement in the gas stream. The well-proven CMOS technology is perfectly suited for high-quality mass production and is the ideal choice for demanding and cost-sensitive OEM applications. Applications ■ Ventilation ■ Anesthesia ■ Inspiratory flow sensing ■ Gas mixing OEM options A variety of custom options can be implemented for high-volume OEM applications (digital interface, custom flow rates, calibration for other gases, different body form factor etc.). Contact us for more information. Sensor electronics The SFM3100 flow meter features a fifth-generation silicon sensor chip and provides an analog output signal. An EEPROM is included to store sensor specific information such as the serial number or customer specific data. See chapter 2.3 for more detail. Direct gas temperature measurement The SFM3100 is equipped with an NTC element centrally positioned in the main flow channel for direct temperature measurement of the gas.

1. Sensor Performance 1.1 Physical spécifications 1 Unless otherwise noted, all sensor spécifications are valid at 25°C with Vdd = 5V and absolute pressure = 966 mbar and horizontal flow direction slm: mass flow measured in liters per minute at standard conditions (T = 20 °C, p = 1013.25 mbar) for "Typ" a CpK of 0.67 is targeted (95% of sensors within the Typ limit) for "Max" no sensor measured outside of this limits will be shipped and a CpK of 1.33 is targeted Including offset, non-linearity, hysteresis Total accuracy/noise level/resolution is a sum of offset and span accuracy/noise...

1.2 Ambient conditions Parameter

Block diagram CMOSens Sensor Flow output (V) Electrical characteristics Electrical properties Supply voltage (VDD) Start-up Time11 Power Consumption Flow output signal Temperature output signal EEPROM I2C communication level Output capacitive load Cload Output resistive load Rload 11 Condition Min. 4.75 range range High Low

The SFM3100 has an on-board EEPROM, which can be accessed over the I2C interface. The EEPROM is read-only and stores sensor specific information such as the serial number or customer specific data. For OEM options please contact Sensirion. The chip enable (E2) of the EEPROM is connected to ground so that the device address of the EEPROM starts with 10100b. The EEPROM is the M24C08-WDW6TP from ST Microelectronics. For more details please refer to the datasheet on the ST.com website. 3.1 Air flow calculation In order to obtain the flow in slm from the voltage flow signal, the measured value...

4. Mechanical Spécifications All dimensions are in millimètres (mm). 5. Instructions for Use 5.1 Calibration orientation The sensors are calibrated horizontally as depicted in the following graph: 5.2 Inlet flow conditions In order to provide good flow conditions, the inner diameter of the connecting tube has to be the same as the inner diameter of the SFM3100 main flow channel (16.6mm). The inlet tube is recommended to be straight and at least 10 cm in length. The SFM3100 is equipped with a mesh on the inlet of the flow channel to improve flow conditions. Please refer to the application...

The sensor is shipped in an antistatic tray to prevent damage by electrostatic discharge. In order to avoid damaging the sensor, ground yourself with a grounding strap or by touching a grounded object before touching the sensor. Furthermore it is advised to store the parts in an antistatic package when not in use. 5.4 ESD - AEC Q 100 002 (4kV HBM) - AEC Q 100 003 (200V MM) For ESD tests of the external EEPROM, please consult the datasheet of this component (see chapter 2.3). Although the sensor complies with these norms, it does not mean the sensor is immune against ESD. The electronics of...

Température Curve of additional température sensor °C

Appendix B: Oxygen flow conversion The O2 flow can be calculated using the following two formulas. (1) ݰݑ[Ȱݑ] = flow signal from sensor (voltage) ɰݐ ְݑ2 = O2 concentration (e.g. 100%, if pure O2 is used) °ݑ[ İݑ0ݑٰݑ] = calculation of flow without O2 correction refer to chapter 3.1: flow calculation ڰݑ İݑ2 [°ݑ0ݑٰݑ]= flow at a specified O2 concentration All other constants for formula (1) and (2) and the matrix for the O2 correction values (QO2 x FO2) can be found on the EEPROM. The values are stored as 16bit Int. Use value FO2,i where QO2,i is closest to Q[slm] (from (1)). EEPROM addresses...

Important Notices Warning, personal injury Do not use this product as safety or emergency stop devices or in any other application where failure of the product could result in personal injury (including death). Do not use this product for applications other than its intended and authorized use. Before installing, handling, using or servicing this product, please consult the datasheet and application notes. Failure to comply with these instructions could result in death or serious injury. If the Buyer shall purchase or use SENSIRION products for any unintended or unauthorized application,...