Flow Sens FS1 Thermal Mass Flow Sensor for all-purpose use in Gases Product The Flow sensor element consists of two temperature depending platinum-resistors, both deposited on one chip. The low-ohm resistor with a small area is used as a heater, whereas the other high-ohm resistor serves to measure the reference temperature. Using a bridge circuit, the differing resistance value of two elements leads to different (self) heating. The (self) heating is dependent upon the applied voltage, the mass flow, and the media in which the sensor is located. Higher voltage increases self heating, a higher flow rate increases cooling. If the self heating is kept constantly by a suitable controller, the voltage increases with higher flow rates and therefore becomes a measure for the mass flow. As a result of his little thermal mass, this sensor has fast heating and cooling response times. The measuring principle of the sensor can be used for large operation ranges, from 00.1m/s up to 100m/s. The Flow Sens is also available with a plastic housing of 6mm. This option provides the user with ideal opportunities to incorporate the element into custom-built applications or specific housings, e.g. into a T-piece. Advantages Easy adaptable for different applications or into housings Simple signal processing and calibration No mechanical moved components Excellent reproducibility Excellent long-term stability Best price-performance ratio Applications HVAC and building control solutions Automotive industry Medical devices Device monitoring Cooling devices Food industry Flow Sens FS1 Thermal Mass Flow Sensor for all-purpose use in Gases Technical Data Measuring principle thermal Measuring range 0 ... 100 m/s Response sensitivity 0.01 m/s Accuracy < 3% current measuring value (dependent on electronic and calibration) Response time t Ca. < 2 s 63% Temperature range -20 ... + 150 C Temperature sensitivity < 0.1 %/K (dependent on electronic) Electrical connection 3 pins, Leads AWG30, insulated with PTFE, or custom specific Heater R (0C) = 45 1% H Referenz element R (0C) = 1200 1% s Required voltages typical 2 - 5 V at T = 30 K ( 0 V 100m / s ) strm Max. heater voltage 0 m/s 3V Substrate material ceramic In general All data are temporary and valid in air. Other media and higher requirements upon request. No responsibility accepted. Construction sizes R H 2.4 mm R S GND 0.15 mm 7 mm 195 mm 6 mm 3 mm 3.5 mm GND R S R H O-Ring 4mm x 1.5mm 4 mm 14 mm 202 mm 6 mm