Campbell Scientific TGA100 Trace Gas Analyzer Manual - Manual (Page 22)

Typical performance for isotope ratio measurements is given in delta notation. For example, the δ 13 C for CO
2
is given
by:
13 1 1000 s
VPDB
R
C
R
δ
 
= − ×
 
 
where R
s
is the ratio of the isotopomer concentrations measured by the TGA100 ( 13 CO
2
/ 12 CO
2
) and R
VPDB
is the
standard isotope ratio ( 13 C/ 12 C). δ 13 C is reported in parts per thousand (per mil or ‰). The 10 Hz noise is the square
root of the Allan variance with no averaging. The calibrated noise assumes a typical sampling scenario: two air sample
intakes and two calibration samples measured in a 1 minute cycle. It is given as the standard deviation of the calibrated
air sample measurements.
Table 2. Typical Isotope Ratio Measurement Noise
Gas Isotope Ratio Wavenumber (cm -1 ) 10 Hz Noise (‰) Calibrated Noise (‰)
δ 13 C 2293.881, 2294.481 0.5 0.1 Carbon
Dioxide
δ 18 O 2308.225, 2308.416 2.5 0.5
δ 18 O 1500.546, 1501.188 2 0.5 Water
δD 1501.813, 1501.846 10 2.5
1.7.2 Physical Specifications
Analyzer
Length: 211 cm (83 in)
Width: 47 cm(18.5 in)
Height: 55 cm (21.5 in)
Weight: 74.5 kg (164 lb)
Optional Cryocooler Compressor
Length: 31 cm (12 in)
Width: 45 cm (18 in)
Height: 38 cm (15 in)
Weight: 32 kg (71 lb)
Power Requirements
Analyzer: 90-264 Vac, 47-63 Hz, 50 W (max) 30 W (typical)
Optional Heater: 90-264 Vac, 47-63 Hz, 150 W (max)
PC: 115/230 Vac, 50/60 Hz, 150 W
Optional Cryocooler Compressor: 100, 120, 220, or 240 Vac, 50/60 Hz, 500 W
Optional sample pump (RB0021-L): 115 Vac, 60 Hz, 950 W (other power options are available)
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