Campbell Scientific EC150 CO2 and H2O Open-Path Gas Analyzer and EC100 Electronics with Optional CSAT3A 3D Sonic Anemometer - Manual (Page 18)

EC150 CO
2
/H
2
O Open-Path Gas Analyzer
Gas analyzer
Measurement precision iii
CO
2
density: 0.2 mg·m –3 (0.15 µmol·mol –1 )
H
2
O density: 0.004 g·m –3 (0.006 mmol·mol –1 )
Factory calibrated range
CO
2
: 0 to 1000 µmol·mol –1
H
2
O: 0 to 72 mmol/mol (37°C dewpoint)
Temperature: − 30° to 50°C
Barometric pressure: 70 to 106 kPa
CO
2
performance
Zero max drift iv : ±0.55 mg·m –3 ·°C –1 (± 0.3
μmol·mol·°C –1 )
Gain drift: ±0.1% of reading·°C –1 (maximum)
Sensitivity to H
2
O: ±1.1 x 10 –4 µmol CO
2
·mol –1 H
2
O (max)
H
2
O performance
Zero max drift iv : ±0.04 g·m –3 ·°C –1
(± 0.05 mmol·mol –1 ·°C –1 )
Gain drift: ±0.3% of reading·°C –1 (maximum)
Sensitivity to CO
2
: ±0.1 mol H
2
O·mol –1 CO
2
(maximum)
CSAT3A sonic measurement precision v
u
x
: 1.0 mm·s –1
u
y
: 1.0 mm·s –1
u
z
: 0.5 mm·s –1
Sonic temperature: 0.025°C
CSAT3A sonic accuracy vi
Offset error
u
x
, u
y
: < ±8 cm·s –1
u
z
: < ±4 cm·s –1
Gain error
Wind vector ±5° horizontal: < ±2% of reading
Wind vector ±10° horizontal: < ±3% of reading
Wind vector ±20° horizontal: < ±6% of reading
iii noise rms, assumes:
o 25°C
o 85 kPa
o 14 g·m -3 H
2
O
o 597 mg·m -3 CO
2
o 25 Hz bandwidth
iv − 30° to 50°C
v noise rms
vi assumes:
o −30° to +50°C
o wind speed <30 m·s -1
o azimuth angles between ±170°
8