Mass Flow Meter (MFM) for Gases

Transcription

1 Mass Flow Meter (MFM) for Gases Type 870 can be combined with Direct flow measurement for nominal flow rates from 0 ml N /min to 80 l N /min (N ) in MEMS technology High accuracy and repeatability Protection class IP6 Optional field bus Type 869 Multichannel program controller Type 00 / or /-way solenoid valve Type 60 /-way solenoid valve Type 6606 / or /-way solenoid valve Mass flow meters are used in pro cess technology for the direct mea surement of the mass flow of gases. In case of volumetric flow meters, it is ne cessary to measure the tem perature and the pressure either the density, because gases change their density or rather their volume de pending on the pressure. The mea surement of the mass flow, on the other hand, is independent of the pressure and the temperature. The digital mass flow meter Type 870 uses a sensor on silicon chip basis (see the description on page ) located directly in the bypass channel. Due to the fact that the sensor is directly in the bypass chan nel a very fast response time of the MFM is reached. The actual flow is given as an analog output signal or could be read out over fieldbus communication. Type 870 can optionally be calibrated for two different gases, the user is able to switch between these two gases. Technische Daten Nominal flow range ) (Q nom ) 0.0 to 80 l N /min ) (ref. to N ) Turn-down ratio :0, wider span on request Operating gas Neutral, non-contaminated gases, others available on request Calibration gas Operating gas or air with correcting function Max. operating pressure (Inlet pressure) Gas temperature Ambient temperature Accuracy (after min warm up time) Repeatability Settling time (t 9% ) Materials Body Housing Seals Up to max. 0 bar (psi), depending on the orifi ce of the valve -0 to +70 C (-0 to +60 C with oxygen) -0 to +0 C ±0.8% o.r. ±0.% F.S. (o.r.; F.S.: of full scale) ±0.% F.S. <00ms Stainless steel PC (Polycarbonate) FKM, EPDM (others on request) Port connection G /, NPT / or compression fi tting Electr. connection Socket M6, round, 8-pin and socket D-Sub HD, -pin Additionally with fi eldbus: With PROFIBUS-DP: Socket M -pin (for IP6) or D-Sub 9-pin With DeviceNet/CANopen: Plug M -pin (for IP6) or D-Sub 9-pin Operating voltage V DC Voltage tolerance ±0% Residual ripple <% ) The nominal fl ow value is the max. fl ow value calibrated which can be controlled. The nominal fl ow range defi nes the range of nominal fl ow rates (full scale values) possible. ) Index N: Flow rates referred to.0 bar and 0 C. Alternatively there is an Index S available which refers to.0 bar and 0º C. The materials of the parts that come into contact with the medium are selected according to customer specification so that the unit can be operated with the complete range of standard process gases. The MassFlowCommunicator software can be used for parameterisation and diagnosis. Typical application areas are gas flow measurement in Test benches Packaging and foodstuff industry Environmental technology Pharmaceutical Biotechnology Power consumption Output signal (signal output) Max. current, volt. output Max. load, current output Digital communication via adapter possible: Fieldbus option Type of protection (with connected cables) max.. W (analog communicator) to W (digital communicator) 0 V, 0 0 V, 0 0 ma or 0 ma 0 ma 600 Ω RS, Modbus RTU (via RS interface) RS8, RS or USB (see accessories table on p. ) PROFIBUS-DP, DeviceNet, CANopen (D-Sub HD covered with sealed plate with fi eldbus MFC) IP6 Dimensions [mm] (without fi tting) See drawings on p. 7 8 Total weight 000 g Mounting position Horizontal or vertical Light emitting diodes (Default, other functions programmable) Binary inputs (Default, other functions programmable) Binary outputs (Default, other functions programmable) Indication for Power, Communication, Limit, Error Three various functions programmable Two relay outputs. Limit (Q nom almost reached). Error (i.e. sensor fault) Load capacity: max. 60 V, A, 60 VA p. /8

2 Measuring Principle The actual flow rate is detected directly by a sensor placed in a bypass channel. This operates according to a thermal principle which has the advantage of providing the mass flow which is independent of pressure and temperature. A small part of the total gas stream is diverted into a small, specifically designed bypassing channel which ensures laminar flow conditions. The sensor element is a chip immersed into the wall of this flow channel. The chip, produced in MEMS technology, contains a heating resistor and two temperature sensors (thermopiles) which are arranged symmetrically upstream and downstream of the heater. The differential voltage of the thermopiles is a measure of the mass flow rate passing the flow sensor. The calibration procedure effectuates a unique assignment of the sensor signal to the total flow rate through the device. Pressure Loss Diagram (ref. to air, with 0μm inlet filter) Δp [mbar] G/ Sub-base The diagram shows exemplarily the pressure loss characteristics when air flowing through. For determining the pressure loss with another gas it needs to calculate the air equivalent and respect the fluidics needed with the other gas Q [l N/min] Nominal Flow Range of Typical Gases (other gases on request) Gas Min. Q nom [l N /min] Argon Helium Carbon dioxide Air Methane Oxygen Nitrogen Hydrogen Max. Q nom [l N /min] Notes regarding the selection of the unit The decisive factors for the perfect functioning of an MFM within the application are the fluid compatibility, the normal inlet pressure and the correct choice of the fl ow meter range. The pressure drop over the MFM depends on the fl ow rate and the operating pressure. Please use the form on page 8 for the information about your specific requirements.. p. /8

3 Ordering Chart for Accessories Article Item No. Connectors/Cables Round plug M6 8-pin (solder connection) Round plug M6 8-pin with m cable Round plug M6 8-pin with 0m cable Plug D-Sub HD -pin with m cable Plug D-Sub HD -pin with 0m cable Adapters ) RS adapter for connection to a computer, connection with an extension cable (item no ) 6 77 Extension cable for RS 9-pin socket/plug m RS-Adapter (RS8 compatible) USB-Adapter (Version., USB socket type B) USB connection cable m Adapter for manual setting of bus address 667 Software MassFlowCommunicator Download unter Accessories for Fieldbus PROFIBUS DP (B-codiert) DeviceNet/ CANopen (A-codiert) M-Plug ) M-socket (coupling) ) Y-junction ) T-junction 98 (auf Anfrage) Shut-off resistor 90 (auf Anfrage) GSD-Datei (PROFIBUS), EDS-Datei (DeviceNet, CANopen) Download unter (unter Typ 87) ) The adapters serve mainly for initial operation or diagnosis. Those are not obligatory for continuous operation. ) The two M connectors as listed above cannot be used together on the same side of the Y-junction. At least one of the two M connection needs to be a prefabricated cable which uses typiclly a thinner connector. Adapter for manual setting of a bus address 667 M P-DP: DVN/CAN: 97 M P-DP: 98 7 DVN/CAN: 97 6 OR T junction P-DP: 98 DVN/CAN: on request RS adapter 6 77 RS adapter Shut-off resistor P-DP: 90 (male) DVN/CAN: on request Female M with cable Male M with cable Y junction P-DP: DVN/CAN: M P-DP: DVN/CAN: 97 6 USB-Adapter p. /8

4 Pin Assignment Socket D-Sub HD Pin Assignment Analogue Control N.C. N.C. ) N.C. N.C. Bus control Actual value output + N.C. Binary input V-Output (only for internal company use) 6 RS TxD (direct connection to computer) 7 Binary input 8 GND (for binary inputs) 9 only company internal use (do not connect!) 0 V-Output (only for internal company use) V-Output (only for internal company use) Binary input Actual value output GND N.C. RS RxD direct connection to computer) DGND (for RS-interface) ) N.C.: not connected (not used) Note: Optional Pin and with bus version as transmitter input possible The cable length for RS/ fl ow value signal is limited to 0 meters. Socket M6, round, 8-pin Pin Assignment V-Supply Relay reference contact Relay reference contact 6 Relay normally closed contact Relay normally open contact 6 V-Supply GND 7 Relay normally open contact 8 Relay normally closed contact Socket D-Sub 9-pin (only with fieldbus version) Pin Assignment PROFIBUS DP DeviceNet/ CANopen Shield Shield N.C. CAN-L data line RxD/TxD - P (B-line) GND RTS N.C. (control signal for repeater) GND N.C. 6 VDD (only for termination N.C. resistor) 7 N.C. CAN-H data line 8 RxD/TxD - N (A-line) N.C. 9 N.C. N.C. p. /8

5 Pin Assignment (continued) PROFIBUS DP socket B-coded M (DPV max. Mbaud) Pin Assignment VDD (only for termination resistor) RxD/TxD N (A-line) DGND RxD/TxD P (B-line) N.C. DeviceNet/ CANopen Plug A-coded M Pin Assignment Shield N.C. 6) DGND CAN_H CAN_L 6) Optional confi guration with V DC possible for power supply via fi eldbus connector. With this no power supply connection on round M6 plug needed. p. /8

6 Dimensions [mm] Standard version x M - 0 deep Mass A G / NPT / with fieldbus DSub M. A A p. 6/8

7 Dimensions [mm] (continued) Flange version x. x 8.8 x 6.. DSub with fieldbus M M. 0 p. 7/8

8 MFC/MFM-applications - Request for quotation Please complete and send to your nearest Bürkert sales centre Company Contact person Note You can fill out the fields directly in the PDF file before printing out the form. Customer No Address Postcode/Town Department Tel./Fax MFC-Application MFM-Application Quantity Required delivery date Medium data Type of gas (or gas proportion in mixtures) Density kg/m 7) Gas temperature [ºC or ºF] ºC ºF Moisture content g/m Abrasive components/solid particles no yes, as follows: Fluidic data Flow range Q nom Min. l N /min 7) l S /min (slpm) 8) Max. m N /h 7) kg/h cm N /min 7) cm S /min (sccm) 8) l N /h 7) l S /h 8) 9) Inlet pressure at Q nom p = bar(g) Outlet pressure at Q nom p = bar(g) Max. inlet pressure P max bar(g) MFC/MFM port connection without screw-in fitting / G-thread (DIN ISO 8/) / NPT-thread (ANSI B.) with screw-in fitting (acc. to specification for pipeline) mm Pipeline (external Ø) inch Pipeline (external Ø) Flange version Installation horizontal vertical, flow upwards Ambient temperature C vertical, flow downwards Material data Body Aluminium Stainless steel Housing Plastic Metal (not with type 87/870 and not with fieldbus) Seal FKM EPDM Electrical data Signals for set point with standard signal with fieldbus and actual value Setpoint actual value Please quote all pressure values as overpressures with respect to atmospheric pressure bar(ü) 7) at:,0 bar(a) and 0ºC 8) at:.0 bar (a) and 0ºC 9) matches with calibration pressure 0- V 0- V PROFIBUS DP M 0-0 V 0-0 V DeviceNet D-Sub 0-0 ma 0-0 ma CANopen (only for type 87/870) -0 ma -0 ma To find your nearest Bürkert facility, click on the orange box In case of special application conditions, please consult for advice. Subject to alteration. Christian Bürkert GmbH & Co. KG /_EU-en_ p. 8/8