Page 413 - Bürkert

Mass Flow Meter (MFM) for Gases

8702 • Direct flow measurement with CMOS-

®
ens technology for nominal flow rates
from 20 mlN/min to 80 lN/min
• High accuracy and quick response
time
• Optional fieldbus

The digital mass flow meter, Type 8702, uses a sensor on silicon chip Dimensions [mm] (see datasheet for more details)
basis located directly in the bypass channel. Due to the fact that the sen-
sor 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.
Typical application areas are gas flow measurement in
• Test benches C
• Packaging and foodstuff industry
• Environmental technology
• Pharmaceutical and Biotechnology
In particular, Type 8702 fulfils the requirements of IP65 protection.

Technical Data
Nominal flow range (Q ) 0.01 to 80 l /min (ref. to N )
2)
1)
nom N 2
Turn-down ratio 1:50, wider span on request
Operating gas Neutral, non-contaminated A
gases, others available on request
Calibration gas Operating gas or air with correcting function
A B C
Max. operating pressure Up to max. 10 bar (145 psi), 115 37 137 B
(Inlet pressure) depending on the orifice of the valve
Gas temperature -10 to +70°C (-10 to +60°C with oxygen)
Ambient temperature -10 to +50°C (others on request)
Accuracy ±0.8% o.R. ±0.3% F.S.
(after 1 min warm up time) (o.R.: of reading; F.S.: of full scale) Digital communication RS232, Modbus RTU (via RS interface)
RS485, RS422 or USB
Repeatability ±0.1% F.S. via adapter possible: (see accessories table)
Settling time (t 95% ) <300 ms Fieldbus option Profibus-DP, DeviceNet, CANopen
Materials (D-Sub HD15 covered with sealed plate with
Body Stainless steel fieldbus MFC)
Housing PC (Polycarbonate) Type of protection IP65
Seals FKM, EPDM (others on request) (with connected cables)
Port connection G 1/4” (others on request)
Total weight 1000 g
Electr. connection Socket M16, round, 8-pin and
socket D-Sub HD15, 15-pin Mounting position Horizontal or vertical
Additionally with fieldbus: With PROFIBUS-DP: Light emitting diodes Indication for Power, Communication, Limit,
Socket M12 5-pin (for IP65) or D-Sub 9-pin (Default, other functions Error
With DeviceNet/CANopen: programmable)
Plug M12 5-pin (for IP65) or D-Sub 9-pin Binary inputs Three various functions programmable
Operating voltage 24V DC (Default, other functions
Voltage tolerance ±10% programmable)
Residual ripple <2% Binary outputs Two relay outputs
(Default, other functions 1. Limit (Qnom almost reached)
Power consumption max. 2.5 W (analog communicator) 2. Error (i.e. sensor fault)
to 5 W (digital communicator) programmable) Load capacity: max. 60 V, 1 A, 60 VA
Output signal (signal output) 0–5 V, 0–10 V, 0–20 mA or 4–20 mA
Max. current, volt. output 10 mA 1) The nominal flow value is the max. flow value calibrated which can be controlled.
Max. load, current output 600 Ω The nominal flow range defines the range of nominal flow rate possible.
2) Index N: Flow rates referred to 1.013 bar(a) and 0 ºC, alternatively also
Index S: Flow rates referred to 1.013 bar(a) and +20 ºC.

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