Design and function
42/14-37-EN Sensyflow
FMT200-D
11
2 Design and function
G01034
1
2
2
Pipe component with external thread fitting
Pipe component with flange connection
Weld-on adapter
Fig. 2
1
Flowmeter sensor Sensyflow FMT200-D
2
Lock nut
The mass flowmeter works according to the thermal measuring principle of a hot-film
anemometer. Heat is drawn out of a heated body by a gas circulating around it. This flow-
dependent cooling is utilized as a measuring effect. Since the heat loss depends on the number
of particles that hit the surface of the heated body, it is possible to directly determine the mass
flow rate. This means there is no need for pressure and temperature influences to be
compensated.
The calibration of the devices is done on a highly precise flow test machine with air as
calibration medium. For standard biogas applications, the calibration data are subsequently
converted, whereby a medium gas composition is based on 53 Vol% methane, 45 Vol% carbon
dioxide and 2 Vol% air. Devices for applications that clearly deviate from this gas composition
must be ordered with a special calibration for biogas. In this case, the exact gas composition is
to be specified with the order.
The measuring systems of the FMT200-D series consist of the following components:
• Flowmeter sensor and
• Pipe component of various types.
