ASF1400 Bidirectional Mass Flow Meter Unique dynamic range: 0.01 sccm 400 sccm Outstanding resolution and accuracy Ultra fast response time Hysteresis & offset free Calibrated & temperature compensated RS-232 and Version 2.2 / November ASF1400 Product Summary The ASF1400 Mass Flow Meter enables extremely Mounted in rugged, chemically inert PBT housing the accurate bidirectional measurement of gas flow over four ASF1400 is suitable for a wide range of applications. Such orders of magnitude. Its leading performance is based on include mass flow metering for process control, medical SENSIRIONs unsurpassed CMOSens sensor technology. applications, heating ventilation and air conditioning With CMOSens , the on-chip sensor element forms an (HVAC) solutions, as well as gas flow metrology. integrated whole with the amplification and A/D converter The sensor housing provides two inlets for measuring the circuit. This results in superior resolution, fast response gas flow and withstands overpressures of 2 bar (29 psi). time and large dynamic range at lowest power The ASF1400 requires a supply voltage of 718Vdc and consumption. provides an RS-232 compliant electrical interface. All measurement data is fully calibrated and temperature compensated by means of an internal microcontroller. ASF1400 MASS FLOW METER GND Power VOLTAGE MASS FLOW VDD Supply REGULATOR /CS CMOSens SENSOR CHIP MICRO SPI MOSI no longer CONTROLLER Interface MISO supported SCK RS232 LINE RxD RS232 DRIVER/ TxD Interface RECEIVER EEPROM MASS FLOW Figure 1: Block Diagram ASF1400 Mass Flow Sensor with CMOSens technology. www.sensirion.com Sensirion AG, Laubisrtistrasse 50, CH-8712 Stfa ZH, Switzerland, Phone: +41 44 306 40 00, Fax: +41 44 306 40 30 THERMAL SENSOR AMPLIFIER ADCASF1400 Bidirectional Mass Flow Meter Introductory Description The heart of the ASF1400 mass flow meter is gas is nitrogen. Please contact SENSIRION, if you powered by Sensirions unsurpassed CMOSens would like to use the sensor for applications with other sensor technology. The ASF1400 mass flow meter gases. therefore provides unbeatable performance at very To get you started quickly, an evaluation package attractive system cost. The lowest detectable gas flow including ASF1400 devices, software, cables, rubber rate is 0.003 sccm, which means a minimum volume hose and bypass is available from Sensirion AG. 3 of 3 mm gas per minute can be measured. Covering at the same time a flow range of more than 4 orders CMOSens sensor technology of magnitude, the ASF1400 sets a new standard CMOSens is the base technology for all Sensirion wherever mass flow has to be measured or multi sensor modules and sensor systems. The controlled. unification of semiconductor chip and sensor The ASF1400 device measures true mass flow technology serves as a platform for highly integrated independent of the ambient temperature and pressure system solutions with excellent sensor precision and changes. You simply connect the gas to be measured reliability. With CMOSens , the on-chip sensor to the ASF1400 device to get an instantaneous gas element forms an integrated whole with a high-end flow rate at a sampling rate of up to 7Hz (please amplification and A/D converter circuit. Due to the contact us for sampling rates of up to 200Hz). compact single-chip design, CMOSens based A flow range between 400 sccm can directly be sensors are very resistant to electromagnetic mea-sured by connecting the ASF1400. To increase disturbances (EMC), another important technical the range, a bypass can be used in conjunction with advantage of this state of the art sensor technology. the ASF1400 device (see Section 1.4 of this data As a result, CMOSens based multi sensor modules sheet). offer excellent sensor precision, fast response time In addition to mass flow, the ASF1400 device and a very large dynamic measurement range. In provides information about the temperature on the addition, the digital intelligence of the CMOSens CMOSens sensor element. Both mass flow and sensor technology enables digital interfaces that temperature data are accessed through an RS-232. permit an easy link with the system of the customer, a The RS-232 interface allows you to directly connect real advantage and benefit that results in ready-to-use the ASF1400 device to a PC or PDA using standard problem solutions (Mount&Sense). terminal software. If a special interface such as 4-20 mA current output or other is required contact Sensirion for a customer specific solution. In general, all gas types can be measured using the ASF1400 product. However, the standard calibration www.sensirion.com Version 2.2 2/9