Aalborg GFM User Manual
Page 10
4.
SPECIFICATIONS
FLOW MEDIUM: Please note that GFM17/37/47/57/67/77 Mass Flow Meters are designed to
work with clean gases only. Never try to meter or control flow rates of liquids with any GFM's.
CALIBRATIONS: Performed at standard conditions [14.7 psia (1.01 bars) and 70
F
F
(21.1
F
C)] unless otherwise requested or stated.
ENVIRONMENTAL (per IEC 664): Installation Level II; Pollution Degree II.
ACCURACY: ±1.5% F.S. (optional enhanced accuracy ±1% F.S.).
REPEATABILITY: ±0.25% of full scale.
TEMPERATURE COEFFICIENT: 0.15% of full scale/
F
C.
PRESSURE COEFFICIENT: 0.01% of full scale/psi (0.07 bar).
RESPONSE TIME: 800 ms time constant; approximately 2 seconds to within ±2% of set
flow rate for 25% to 100% of full scale flow rate.
GAS PRESSURE: 1000 psig (69 bars) GFM 17, 37 and 47; 500 psig (34.5 bars) GFM 57,
67 and 77; optimum pressure is 20 psig (1.4 bars).
GAS AND AMBIENT TEMPERATURE: 32
F
F to 122
F
F (0
F
C to 50
F
C).
14
F
F to 122
F
F (-10
F
C to 50
F
C) - Dry gases only.
RELATIVE GAS HUMIDITY: Up to 70%.
LEAK INTEGRITY: 1 x 10
- 7
sccs He max. to the outside environment.
ATTITUDE SENSITIVITY: Incremental deviation of up to 1% full scale from stated accura-
cy, after re-zeroing.
OUTPUT SIGNALS: Linear 0-5 VDC (1000
Ω minimum load impedance) and 4-20 mA
self-powered sourcing type, non-isolated (0-500 loop
Ω resistance); 20 mV peak to peak
max noise.
Contact your distributor or Aalborg
7
for optional RS232 or RS-485 interfaces.
6
TRANSDUCER INPUT POWER:
GFM models with 12 VDC power input (serial numbers below 340621-1):
12 VDC, 200 mA maximum;
GFM models with 24 VDC power input (serial numbers below 340621-1):
+24 VDC, 200 mA maximum;
GFM models with universal power input (serial numbers above 340621-1):
any voltage between +12 and +26 VDC, 200 mA maximum;