ASF1430 Bidirectional Mass Flow Meter Total mass flow integrator Data rates up to 200 Hz Unique dynamic range: 0.01 sccm 400 sccm Outstanding resolution and accuracy Calibrated & temperature compensated RS-232 RoHS compliant v 2.3 / November 2008 ASF1430 Product Summary The ASF1430 Mass Flow Meter enables extremely Mounted in rugged, chemically inert PBT housing the accurate bidirectional measurement of fast changing ASF1430 is suitable for a wide range of applications. gas flow over four orders of magnitude. Its leading Such include mass flow metering for process control, performance is based on SENSIRIONs unsurpassed medical applications, heating ventilation and air CMOSens sensor technology which combines a high conditioning (HVAC) solutions, as well as gas flow precision sensor element with the amplification and metrology. A/D converter circuit on one single CMOS chip. This The sensor housing provides two inlets for measuring results in superior resolution, fast response time and the gas flow and withstands overpressures of 2 bar (29 large dynamic range at lowest power consumption. psi). All measurement data is fully calibrated and The ASF1430 requires a supply voltage of 718Vdc temperature compensated by means of an internal and provides an RS-232. microcontroller. ASF1430 is RoHS compliant. CMOSens SENSOR CHIP Output of integrated linearized and no longer supported temperature compensated total mass flow within integration period Resolution settings determine the integration period between 5ms and Integrated Resolution 640 ms temperature settings sensor Figure 1: Block Diagram ASF1430 Mass Flow Sensor. www.sensirion.com Sensirion - the sensor company THERMAL Signal for Massflow SENSOR Fast ultra low noise AMPLIFIER amplification 50 kHz 50 kHz sampling of ADC amplified signal 50 kHz Signal integration for Integrator 5 ms (256 samples) 200 Hz Linearization of each Linearization 5 ms sensor integral 200 Hz Temperature compensation T-comp. of each 5 ms sensor integral 200 Hz Integration of linearized and T-compensated Integrator 5ms sensor integral 1.5 - 200 Hz RS-232 SPI output Input / OutputASF1430 Bidirectional Mass Flow Meter Introductory Description The heart of the ASF1430 mass flow meter is the ASF1430 device to a PC or PDA using standard powered by Sensirions unsurpassed CMOSens terminal software. If a special interface such as 4-20 sensor technology. The ASF1430 mass flow meter mA current output or other is required contact therefore provides unbeatable performance at very Sensirion for a customer specific solution. attractive system cost. The lowest detectable gas flow In general, all gas types can be measured using the rate is 0.0143 sccm, i.e. a minimum volume of 14.3 ASF1430. However, the standard calibration gas is 3 mm gas per minute can be measured. Covering at nitrogen. Please contact SENSIRION, if you would the same time a flow range of more than 4 orders of like to use the sensor for applications with other magnitude, the ASF1430 sets a new standard gases. wherever mass flow has to be measured or ASF1430 is RoHS compliant. controlled. The ASF1430 mass flow sensor runs with an internal CMOSens sensor technology flow integration time of 5ms. This allows correct measurement and display of fast changing signals. CMOSens is the base technology for all Sensirion But very often a precise total flow over a longer period multi sensor modules and sensor systems. The union is of higher interest than a fast single measurements. of semiconductor chip and sensor technology serves For this purpose the ASF1430 can be set to slower as a platform for highly integrated system solutions read out times (see 0). The sensor internally still with excellent sensor precision and reliability. With integrates in 5 ms slices and recognizes fast signal CMOSens , the on-chip sensor element forms an changes but for the read out the total flow over the integrated whole with a high-end amplification and whole period is calculated. The ASF1430 mass flow A/D converter circuit. Due to the compact single-chip meter therefore is exceptionally well suited for difficult design, CMOSens based sensors are very resistant measurement conditions when fast changing gas to electromagnetic disturbances (EMC), another flows must be monitored and summed up precisely. important technical advantage of this state of the art The ASF1430 device measures true mass flow sensor technology. As a result, CMOSens based independent of the ambient temperature and pressure multi sensor modules offer excellent sensor precision, changes. You simply connect the gas to be measured fast response time and a very large dynamic to the ASF1430 device to get an instantaneous gas measurement range. In addition, the digital mass flow integral with a selectable integration time intelligence of the CMOSens sensor technology between 5 ms and 640 ms. enables digital interfaces that permit an easy link with A flow range between 400 sccm can directly be the system of the customer (Mount&Sense). measured by connecting the ASF1430. To increase the range, a bypass can be used in conjunction with the ASF1430 device (see Section 1.5 of this data sheet). In addition to mass flow, the ASF1430 device provides information about the temperature on the CMOSens sensor element. Both mass flow and temperature data are accessed through an RS-232. The RS-232 interface allows you to directly connect www.sensirion.com Data Sheet ASF1430 - v 2.3 / April 2008 2/12