KROHNE GFM 700 EN - Manual (Page 5)

5
1
GFM 700 Ultrasonic gas flowmeter
First ultrasonic gas flowmeter
with two beams
Non-contact ultrasonic gas flow measurement
and volume counting, suitable for
all gases available meter sizes DN 50-600
and 2”-24”.
Wide range of application
The large range of products that can be
measured accurately and easily make this a
truly universal device. Just a few examples:
Natural gas
• Air
• Methane
• Nitrogen
• Determination of the molecular weight of
gases
• Measurement in hazardous locations, Zones 1 and 2
Calibrated on EN 17025 accredited calibration rigs,
calibration accuracy better than 99.97% of the
measured value.
2
Size, flow velocity, flowrate
Selection of meter size / nominal pipe size
Flow velocitys in m/s or ft/s and the flowrate in m3/h or
US Gal / min can be determinded for each meter size
(DN) using the Tables below. Precise determination of flow velocities
For range setting, use the flow table below to determine
the precise flow velocity for each nominal pipe size.
Example: v in m/s Example: v in ft/s
Nominal pipe size DN 150
Required measuring range 1000 m
3 /h
Nominal pipe size 6”
Required measuring range 5000 US Gal / min
For a flow velocity of 1 m/s at DN 150,
the table gives a flowrate of 63.617 m3/h.
For 1000 m
3 /hr, the flow velocity v is thus
For a flow velocity of 3.3 ft/s at 6’’,
the table gives a flowrate of 280.11 gal/min.
For 5000 Gal / min, the flow velocity v is thus
1000 m 3 /h x 1 m/s
v = -------------------------- = 15.72 m/s
63.617 m
3 /h
5000 US / min x 3.3 ft/s
v = ---------------------------------- = 58.91 ft/s
280.11 US Gal / min
Flowtable for v = 1 m/s Flowtable for v = 10 ft/s
Meter size Flow Meter size Flow
in mm in inches m 3 /h in inches in mm US Gal/min
DN 50 2 7.0686 2 DN 50 31.13
DN 65 2 ½ 11.946 3 DN 80 79.68
DN 80 3 18.096 4 DN 100 124.49
DN 100 4 28.274 5 DN 125 194.52
DN 125 5 44.179 6 DN 150 280.11
DN 150 6 63.617 8 DN 200 497.98
DN 200 8 113.10 10 DN 250 778.05
DN 250 10 176.71 14 DN 350 1525.0
DN 300 12 254.47 16 DN 400 1991.9
DN 350 14 346.36 20 DN 500 3112.8
DN 400 16 452.39 24 DN 600 4418.8
DN 500 20 706.86
DN 600 24 1017.9