8702

p. 1/8www.burkert.com

Mass Flow Meter for Gases (MFM)

Type 8702 can be combined with…

•Nominalflowrangesfrom0.010lN/minto80lN/min

•Highaccuracy

•Veryfastresponsetimes

•ProtectionclassIP65

•Optional:Fieldbusinterface

1)Thenominalflowvalueisthemax.flowvaluecalibratedwhichcanbecontrolled.Thenominalflowrangedefinestherangeofnominalflowrates(fullscalevalues)possible.

2)IndexN:Flowratesreferredto1.013barand0°C.AlternativelythereisanIndexSavailablewhichrefersto1.013barand20°C.

Nominal flow range1) (Qnom) 0.01…80lN/min2)(ref.toN2)

Turn-down ratio 1:50,widerspanonrequest

Operating gas Neutral,non-contaminatedgases,othersavailableonrequest

Calibration gas Operatinggasorairwithcorrectingfunction

Max. operating pressure(Inletpressure)

Uptomax.10bar(145psi),dependingontheorificeofthevalve

Gas temperature -10…+70°C(-10…+60°Cwithoxygen)

Ambient temperature -10…+50°C

Accuracy (after1minwarmuptime) ±0.8%o.R.±0.3%F.S.(o.R.;F.S.:offullscale)

Repeatability ±0.1%F.S.

Settling time (t95 %) <300ms

MaterialsBodyHousingSeals

StainlesssteelPC(Polycarbonate)FKM,EPDM(othersonrequest)

Port connection G¼",NPT¼"orcompressionfitting

Electr. connection

Additionallywithfieldbus:

SocketM16,round,8pinandsocketD-SubHD15,15pinWithPROFIBUS-DP:SocketM125pin(forIP65)orD-Sub9pinWithCANopen:PlugM125pin(forIP65)orD-Sub9pin

Operating voltage 24VDC

Voltage tolerance ±10%

Residual ripple <2%

Power consumption max.2.5W(analogcommunicator)to5W(digitalcommunicator)

Output signal (signaloutput) Max.current,volt.output Max.load,currentoutput

0…5V,0…10V,0…20mAor4…20mA10mA600Ω

Digital communication viaadapterpossible:

RS232,ModbusRTU(viaRSinterface)RS485,RS422orUSB(seeaccessoriestableonp.3)

Fieldbus option PROFIBUS-DP,CANopen(D-SubHD15coveredwithsealedplatewithfieldbusMFC)

Type of protection (withconnectedcables)

IP65

Dimensions [mm] (withoutfitting) Seedrawingsonp.7-8

Total weight 1000g

Mounting position Horizontalorvertical

Light emitting diodes(Default,otherfunctionsprogrammable)

IndicationforPower,Communication,Limit,Error

Binary inputs(Default,otherfunctionsprogrammable)

Threevariousfunctionsprogrammable

Binary outputs(Default,otherfunctionsprogrammable)

Tworelayoutputs1.Limit(Qnomalmostreached)2.Error(i.e.sensorfault)Loadcapacity:max.60V,1A,60VA

Technische Daten

Type 8619

Multichannel program controller

Type 0330

3/2 or 2/2 way solenoid valve

Typ 8611

eCONTROL

Typ 6027

2/2 way plunger valve

The mass flow meter (MFM) type 8702 is sui-ted for measuring the mass flow of gases over a big flow range. The thermal MEMS sensor is located directly in the gas stream and therefore reaches very fast response times.

Type 8702 can optionally be calibrated for two different gases; the user can switch between these two gases. As electrical interfaces both, analog standard signals and fieldbuses are available.

Type 8712 is especially designed for use in harsh environments due to the high protection class.

8702

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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 provid-ing 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 tem-perature sensors (thermopiles) which are arranged symmetrically upstream and downstream of the heater. The differential voltage of the thermopiles is a meas-ure 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.

Gas Min. Qnom[lN/min]

Max. Qnom[lN/min]

Argon 0.01 80Helium 0.01 500Carbon dioxide 0.02 40Air 0.01 80Methane 0.01 80Oxygen 0.01 80Nitrogen 0.01 80Hydrogen 0.01 500

Nominal Flow Range of Typical Gases(other gases on request)

0

10

20

30

40

50

60

70

80

90

100

110

120

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80

Q [lN/min]

∆p [mbar]

G1/4

Sub-base

Pressure Loss Diagram (ref. to air, with 250µm inlet filter)

The diagram shows exemplarily thepressure loss characteristics when airflowing through.For determining the pressure losswith another gas it needs to calculatethe air equivalent and respect thefluidics needed with the other gas.

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 correctchoice 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..

8702

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Ordering Chart for Accessories

Article Article no.

Connectors/Cables

RoundplugM168pin(solderconnection) 918299RoundplugM168pinwith5mcable 787733RoundplugM168pinwith10mcable 787734PlugD-SubHD1515pinwith5mcable 787735PlugD-SubHD1515pinwith10mcable 787736Adapters3)

RS232adapterforconnectiontoacomputer,connectionwithanextensioncable(itemno.917039) 654757ExtensioncableforRS2329pinsocket/plug2m 917039RS422-Adapter(RS485compatible) 666370USB-Adapter(Version1.1,USBsockettypeB) 670696USBconnectioncable2m 772299Adapterformanualsettingofbusaddress 667525SoftwareMassFlowCommunicator Downloadunter

www.buerkert.com

Accessories for Fieldbus PROFIBUS DP(B-codiert)

CANopen(A-codiert)

M12-Plug4) 918198 917115M12-socket(coupling)4) 918447 917116Y-junction4) 902098 788643T-junction 918531 (aufAnfrage)

Shut-offresistor 902553 (aufAnfrage)

GSD-Datei(PROFIBUS),EDS-Datei(CANopen) Downloadunterwww.buerkert.com(unterTyp8712)

3)Theadaptersservemainlyforinitialoperationordiagnosis.Thosearenotobligatoryforcontinuousoperation.4)ThetwoM12connectorsaslistedabovecannotbeusedtogetheronthesamesideoftheY-junction.AtleastoneofthetwoM12connectionneedstobeaprefabricatedcablewhich

usestypicllyathinnerconnector.

M12 P-DP: 918 198DVN/CAN: 917 115

USB-Adapter 670 696

RS422 adapter 666 370

Female M12 with cable

M12 P-DP: 918 198DVN/CAN: 917 116

OR

RS232 adapter654 757

Adapter for manual setting of a bus address667 525

M12 P-DP: 918 447DVN/CAN: 917 116

Shut-off resistorP-DP: 902 553 (male)DVN/CAN: on request

Male M12 with cable

T junctionP-DP: 918 531DVN/CAN: on request

Y junctionP-DP: 902 098DVN/CAN: 788 643

8702

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Socket D-Sub HD15 Pin Assignment

Analogue Control Bus control

1 N.C. N.C.5)

2 N.C. N.C.

3 Actualvalueoutput+ N.C.

4 Binaryinput2

5 12V-Output(onlyforinternalcompanyuse)

6 RS232TxD(directconnectiontocomputer)

7 Binaryinput1

8 GND(forbinaryinputs)

9 onlycompanyinternaluse(donotconnect!)

10 12V-Output(onlyforinternalcompanyuse)

11 12V-Output(onlyforinternalcompanyuse)

12 Binaryinput3

13 ActualvalueoutputGND N.C.

14 RS232RxDdirectconnectiontocomputer)

15 DGND(forRS232-interface)

5)N.C.:notconnected(notused)Note:–OptionalPin1and2withbusversionastransmitterinputpossible–ThecablelengthforRS232/flowvaluesignalislimitedto30

meters.

Socket M16, round, 8 pin Pin Assignment

1 24V-Supply+

2 Relay1–referencecontact

3 Relay2–referencecontact

4 Relay1–normallyclosedcontact

5 Relay1–normallyopencontact

6 24V-SupplyGND

7 Relay2–normallyopencontact

8 Relay2–normallyclosedcontact

Socket D-Sub 9 pin (only with fieldbus version)

Pin Assignment

PROFIBUS DP CANopen

1 Shield Shield

2 N.C. CAN-Ldataline

3 RxD/TxD-P(B-line) GND

4 RTS(controlsignalforrepeater)

N.C.

5 GND N.C.

6 VDD(onlyforterminationresistor)

N.C.

7 N.C. CAN-Hdataline

8 RxD/TxD-N(A-line) N.C.

9 N.C. N.C.

Pin Assignment

1

2

3

4

5

6

7 8

12345

6789

15 14 13 12 11

12345

678910

8702

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PROFIBUS DP – socket B-coded M12 (DPV1 max. 12 Mbaud)

Pin Assignment

1 VDD(onlyforterminationresistor)

2 RxD/TxD–N(A-line)

3 DGND

4 RxD/TxD–P(B-line)

5 N.C.

CANopen – Plug A-coded M12 Pin Assignment

1 Shield

2 N.C.6)

3 DGND

4 CAN_H

5 CAN_L6)Optionalconfigurationwith24VDCpossibleforpowersupply

viafieldbusconnector.WiththisnopowersupplyconnectiononroundM16plugneeded.

Pin Assignment (continued)

12

3

4

5

2 1

4

3

5

8702

p. 6/8

115

2.4

A

12

A

12

12.5

137

37

3.929.21.9

25

42

71

23

2x M4 - 10 deep

973.8

111

111.

5

Dimensions [mm]

Standard version Mass A

G¼NPT¼

with fieldbus

DSub M12

8702

p. 7/8

M4

10

2.4

3.8

44.5

0

25

42

71

137.15

52

4x 4.5 2x 8.8

44.5

44.5

2x 6

0 4 10 32

66.5 83 92 111

115

111

113.

8

Dimensions [mm] (continued)

Flange version

with fieldbus

DSub M12

8702

p. 8/8

Incaseofspecialapplicationconditions,pleaseconsultforadvice.

Subjecttoalteration.©ChristianBürkertGmbH&Co.KG 1803/8_EU-en_00891856

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MFC/MFM-applications - Request for quotation

Please complete and send to your nearest Bürkert sales centre

MFC-Application MFM-Application Quantity Required delivery date

Medium dataType of gas (or gas proportion in mixtures)

Density kg/m3 7)

Gas temperature [ºC or ºF] ºC ºF

Moisture content g/m3

Abrasive components/solid particles no yes, as follows:

Fluidic dataFlow range Qnom Min. lN/min7)

lS/min (slpm) 8)

Max. mN3/h7)

kg/h

cmN3/min7) cmS

3/min (sccm) 8)

lN/h7) lS/h8)

Inlet pressure at Qnom9)

p1= bar(g) •Outlet pressure at Qnom p2= bar(g) •Max. inlet pressure P1 max bar(g) •MFC/MFM port connection without screw-in fitting

¼" G-thread (DIN ISO 228/1)

¼" NPT-thread (ANSI B1.2)

with screw-in fitting (acc. to specification for pipeline)

mm Pipeline (external Ø)

inch Pipeline (external Ø)

Flange version

Installation horizontal

vertical, flow upwards vertical, flow downwards

Ambient temperature °C

Material dataBody Aluminium Stainless steel

Housing Plastic Metal (not with type 8712/8702 and not with fieldbus)

Seal FKM EPDM

Electrical dataSignals for set point with standard signal with fieldbus

and actual value Setpoint actual value

0 … 5 V 0 … 5 V PROFIBUS DP M12 0 … 10 V 0 … 10 V CANopen D-Sub 0 … 20 mA 0 … 20 mA 4 … 20 mA 4 … 20 mA

• Please quote all pressure values as overpressures with respect to atmospheric pressure bar(ü)7)at:1.013bar(a)and0°C 8)at:1.013bar(a)and20°C 9)matcheswithcalibrationpressure

Note

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