Datasheet Mass Flow Meter EM1 for Gases
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CMOSens® EM1 Mass Flow Meter for Gases CMOSens® technology Unbeatable price/performance ratio High output data speed (up to 200 Hz) Wide dynamic range (1:100 with 3% m.v. accuracy) Various maximum flow ranges: up to 200 ln/min (FS) Digitally calibrated & temperature compensated RS232 interface RoHS compliant v 3.0/ March 2009 CMOSens® EM1 Product Summary The CMOSens® EM1 Mass Flow Meter (MFM) enables fast and economical measurement of gas flows over a very wide dynamic range. Its leading price/performance ratio is based on Sensirion's unsurpassed CMOSens® sensor technology which combines a sensor element with the amplification and A/D converter circuit on one single CMOS chip. This results in good performance, fast response time and large dynamic range at very attractive cost. All measurement data is fully calibrated and temperature compensated by means of an internal micro controller. Mounted in rugged, chemically inert housing the CMOSens® EM1 Mass Flow Meter is suitable for a wide range of applications. Such include mass flow metering for process control, medical applications and fuel cells. The sensor housing provides two inlets for measuring the gas flow and withstands overpressures of 8 bar (116 psi). The CMOSens® EM1 Mass Flow Meter requires a supply voltage of 7-18 Vdc and provides an RS232 electrical interface. EM1 is RoHS compliant. CMOSens® SENSORCHIP CMOSens* S. | O .s 5°" S .E ni P SI ^ Cl a E i/J to no longer supported Si =h to ף ll ta c : CECA ■ Ilil □ -*V*. N X je < : M I io lO ■A < Resolution settings dtermine the intgration period between 5ms and 540 m s Integrated R驩solution temprature settitigs sensor Figure 1 : Block Diagram CMOSens® EM1 Mass Flow Meter. www.sensirion.com Data Sheet EM1 - v 3.0 / March 2009 1 / 14

CMOSens® EM1 Mass Flow Meter for Gases Introductory Description The heart of the CMOSens® Mass Flow Meter is powered by Sensirion's unsurpassed CMOSens® sensor technology. The CMOSens® EM1 Mass Flow Meter therefore provides unbeatable performance at very attractive system cost. One single device covers a range of 0.05 ln/min up to 200 ln/min . The CMOSens® EM1 runs with an internal flow integration time of 5ms. This allows correct measurement and display of fast changing signals. But very often a precise total flow over a longer period is of higher interest than a fast single measurement....

Datasheet_SHT7x_V5_C1 table.main {} tr.row {} td.cell {} div.block {} div.paragraph {} .font0 { font:5.00pt "Tahoma", sans-serif; } .font1 { font:6.00pt "Tahoma", sans-serif; } .font2 { font:7.00pt "Tahoma", sans-serif; } .font3 { font:8.00pt "Tahoma", sans-serif; } .font4 { font:10.00pt "Tahoma", sans-serif; } CMOSens® EM1 Mass Flow Meter for Gases 1 CMOSens® EM1 Mass Flow Meter Performance Table 1: Specifications of EM1 Mass Flow Meter - low flow ranges. Specification Condition Value Unit Model Number EM1_H... EM1_L... Flow Range1 0-0.05 0 - 0.5 ln/min Performance | Accuracy2,3 2.5 - 100%...

CMOSens® EM1 Mass Flow Meter for Gases Table 3: Additional Specifications of EM1 Mass Flow Meter - all flow ranges. Spcification Condition Value Unit Temperature Sensor (measured mdia) Dynamic Range 0 - 60 / 32 - 140 °C / °F Resolution 0.1 K Accuracy 2 K Electrical Output RS 232 Supply Voltage + 7 - + 18 VDC Electrical Connector Molex Mechanical Length 13.6 / 5.35 cm / inch Width 4.4 / 1.73 cm / inch Height 8.18 / 3.2 cm / inch Weight (straight / angle connector) 165 / 105 g Mechanical Connector G 3/8 inch Maximum Operating Pressure1 8 / 116 bar / psi Burst Pressure 40 / 580 bar / psi...

CMOSens® EM1 Mass Flow Meter for Gases 1.1 Gas Flow Characteristics Figure 2 shows the applied gas flow vs. the digital output of the CMOSens® EM1 Mass Flow Meter for the 200 ln/min version. CMOSens® EM1 is available for air and nitrogen. Other gas types are available on request. In Figure 3 the repeatability of the CMOSens® EM1 devices is compared with the repeatability of a typical Mass Flow Controller (MFC). It emphasizes the superior performance of the CMOSens® EM1 Mass Flow Meter. 250 r CL o LU 200 150 100 50 0 50 100 150 Mass Flow [ln/min] 200 250 CD > ■o ca eu E '(5 j5 eu cp eu 2.0...

CMOSens® EM1 Mass Flow Meter for Gases duration and accuracy of the temperature update to the maximum. By default temperature updates are done automatically every 60 seconds (INT=12000). 1.4 Gas Flow and Pressure Diffrence The CMOSens® EM1 is calibrated for mass flow measurement. However, there is a well defined relation between mass flow and pressure drop. This relation is shown in Figure 4. 1.6 Operation with different gas types The CMOSens® EM1 mass flow sensor is available in different versions. For all versions the safety restrictions in chapter 1.7 must be observed. For standard...

CMOSens® EM1 Mass Flow Meter for Gases 2.2 Power supply The CMOSens® EM1 Mass Flow Meter requires a voltage supply between 7V and 18 V. Since this voltage is internally regulated, there are no stringent requirements as far as ripple and stability are concerned. 2.3 Digital Interface The CMOSens® EM1 Mass Flow Meter has a: bidirectional RS232 to set configuration and to get flow or temperature values. The in earlier versions available SPI interface is no longer specified, due to changed specifications of electronic components. If you require the SPI functionality contact Sensirion....

CMOSens® EM1 Mass Flow Meter for Gases 3 Configuration and Commands 3.1 Device Configuration The CMOSens® EM1 device accepts a set of commands. They can only be sent through its RS232 interface (see Table 6 for valid commands; for correct settings of the RS232 refer to Section 2.1). This allows the user to configure the CMOSens® EM1 device. Since the configuration is stored in the internal EEPROM, it is maintained after power interruptions. Table 6: RS232 Interface commands the exception of the stop s command, all commands have to be sent in the ASCII-format and terminated by the return key...