SFM3200-AW

Data Sheet – SFM3200-AW Digital Flow Meter for medical applications      Low pressure drop Expiratory flow sensor Flow range: -100 slm to +250 slm (bi-directional) Superior performance at low flows Autoclavable & cleanable Product Summary The SFM3200-AW sensor is Sensirion’s digital flow meter designed for medical applications. It measures the flow rate of air, oxygen and other non-aggressive gases with superb accuracy. A special design of the flow channel results in a very low pressure drop through the flow body of the sensor. Combined with its ability to withstand autoclave procedures, the SFM3200-AW is extremely suited to expiratory flow measurements in medical ventilation and other respiratory applications. The SFM3200 has been designed with the medical professionals in mind. It features medical cones for Applications  Ventilation  Anesthesia  Respiratory measurements  Expiratory flow measurement  Metabolic Measurements OEM options A variety of custom options can be implemented for highvolume OEM applications (custom flow rates, calibration for other gases, different body form factor etc.). Contact us for more information. www.sensirion.com pneumatic connection to standard breathing circuits and a mechanical interface for an easy and reliable electrical reconnection. The sensor element , signal processing and digital calibration are on a single microchip assuring very fast signal processing time, best-in-class accuracy and superior robustness to rough handling and adverse conditions. The well-proven and patented CMOSens® sensor technology is perfectly suited for high-quality mass production and is the ideal choice for demanding and costsensitive OEM applications. Sensor chip The SFM3200 flow meter features a fifth-generation silicon sensor chip. In addition to a thermal mass flow sensor element, the chip contains an amplifier, A/D converter, EEPROM memory, digital signal processing circuitry, and interface. Due to seamless integration of signal acquisition and processing on the single silicon die significant performance and cost benefits are achieved. Version 1 –January 2019 1/7 1. Sensor Performance 1.1 Physical specifications1 Parameter Flow range Accuracy5 Noise Level7 Accuracy Shift Due to Temperature Variation5,8 Resolution (14bit) Pressure drop 1.2 Condition span (-40 to +80) slm span (-60 to +100) slm span full range offset span 50 slm span > 100slm offset span offset span offset @ 60 slm @ 100 slm @ 200 slm Value -100 … +250 3 Typ. Max 4 2 3 3 5 7 10 0.05 0.1 0.6 1.0 1.0 2.0 2 4.5 0.034 0.07 0.4 0.5 0.015 0.02 0.07 0.04 100 / 0.41 150 / 0.62 250 / 0.81 300 / 0.97 750 / 3.02 1100 / 4.44 Unit slm2 % m.v.6 slm2 % m.v6 % m.v6 slm2 % m.v./10˚C slm/10˚C % m.v. 6 slm2 Pa / inH2O Ambient Conditions Parameter Calibrated Temperature Range Operating Temperature Range Storage Temperature Operating Pressure Range Burst Overpressure Condition T(environment)=T(gas) 15% rel. hum. 10-95% rel. hum. (non cond.) 10-95% rel. hum. (non cond.) absolute gauge Value Unit +10 … +50 °C +10 … +50 -25 … +65 0.66 – 1.07 0.25 °C °C bar bar Unless otherwise noted, all sensor specifications are valid at 25°C with Vdd = 5V and absolute pressure = 966 mbar and horizontal flow. 2 slm: mass flow measured in liters per minute at standard conditions (T = 20 °C, p = 1013.25 mbar) 3 for "Typ" a CpK of 0.67 is targeted (95% of sensors within the Typ limit) 4 for "Max" no sensor measured outside of this limits will be shipped and a CpK of 1.33 is targeted 5 Total accuracy/repeatability is a sum of zero-point and span accuracy/repeatability. 6 %m.v. = % measured value = % of reading 7 noise level defined as standard deviation of individual sensor readings, measured at full sampling rate (typ: average of noise level ; max: at least 99.99% of sensors have a noise level below indicated value) 8 these effects need to be added to the initial values if applicable 1 www.sensirion.com Version 1 –January 2019 2/7 1.3 Media compatibility Parameter Calibration 9 Media Compatibility Wetted Materials RoHS, REACH Value Air Air, N2, O2, other non- aggressive gases Si, Si3N4, SiOx, Gold, Epoxy, Glob Top, PPSU, Silicone RoHS and REACH compliant The sensor can be used with gas mixtures, such as breath gas with typically 4% CO2 and 100% high humidity. Please ask Sensirion for details and error estimates. 2. Electrical Specifications 2.1 Electrical characteristics Electrical properties Interface Default Sensor Address Update Time Soft Reset Time Start-up Time 10 Supply Voltage Communication Level Power Consumption Electrical Connector External Heater Power Rating External Heater Resistance Output signal resolution Scale Factor Flow Offset Flow Scale Factor Temperature Offset Temperature 2.2 Pin layout Condition Value I2C 64 (h40) 0.5 80 100 5V +/-5% 14 bit Max. Min 2.5 GND High Low Unit ms ms ms V Max VDD 1.1 < 50 See section 2.2 and 3.2 0.5 51 14 120 32’768 (h8000) 100 20’000 Max. Typ. Air 2.3 V mW W Ω bit 1/slm 1/°C Conversion to Physical Values In order to obtain the measured flow/temperature in [slm]/[°C], the measured value needs to be converted using the following formula: 𝑓𝑙𝑜𝑤 [𝑠𝑙𝑚] = 𝑚𝑒𝑎𝑠𝑢𝑟𝑒𝑑 𝑣𝑎𝑙𝑢𝑒 − 𝑜𝑓𝑓𝑠𝑒𝑡 𝑓𝑙𝑜𝑤 𝑠𝑐𝑎𝑙𝑒 𝑓𝑎𝑐𝑡𝑜𝑟 𝑓𝑙𝑜𝑤 Please note that the first measurement performed directly after chip initialization is not valid. 9 Contact Sensirion for information about other gases, wider calibrated temperature ranges and higher storage temperatures. 4.75V is reached 10 After www.sensirion.com Version 1 –January 2019 3/7 3. Mechanical Specifications 3.1 Connection with medical cones Fittings of the SFM3200 sensor correspond to the international standard ISO5356-1:2004. Details about this type of connection can be found in the description of the standard. 3.2 Mechanical/Electrical Interface 3.1 Dimensions SFM3200-AW has been designed for use in an expiratory environment. Therefore the sensor has been designed for a connector that can be easily connected and disconnected. The connector itself is not provided by Sensirion as a standard product but Sensirion can help with design recommendations. Parameter Length Inner diameter Value 73.0 19 Unit mm mm Downstream conical cone11 22 mm Upstream conical socket9 22 mm Weight