Bio-Science CI-900, Руководство по эксплуатации

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CI-900 Instruction Manual 8/10/2015
1554 NE 3
rd
Ave, Camas, WA 98607, USA Phone: (360) 833-8835
sales@ cid-inc .com www.cid-inc.com
21
GC Emulation Mode
To use the CI-900 to analyze a small sample in a syringe, the GC Emulation Mode should be used.
With the simple addition of our inline injection port, small volumes of analyte can be accurately
measured. The use of GC emulation mode requires an ethylene standard, preferably in the same
concentration range of the sample to be measured. GC Emulation Mode is available for the optional
sensors for CO
2
and O
2
. Calibration standard gas is not required for CO
2
or O
2
in this mode, only for
ethylene. Simultaneous results can be collected for all enabled sensors.
Figure 13: GC emulation port connected to front of instrument for small volume samples.
The GC emulation mode employs a patent pending Flow Inject Analysis method to determine
ethylene concentrations ranging from 0.2-20 ppmv with
sample volumes from 10-15ml. Just like
a GC, a simple estimation accurate up to +/-0.1ppmv is made by comparing the area counts of the
unknown sample to a known concentration. As shown by Equation 1 below, the injection volume is
determined by the expected concentration of ethylene and the detection limits of the sensor. If
interfering gases are expected, their expected concentrations must be subtracted from the reported
ethylene concentration.
Equation 1:
0.2 𝑝𝑝𝑚𝑣 ≤
𝐼𝑛𝑗𝑒𝑐𝑡𝑖𝑜𝑛 𝑉𝑜𝑙𝑢𝑚𝑒∗𝐸𝑥𝑝𝑒𝑐𝑡𝑒𝑑 𝐸𝑡ℎ𝑦𝑙𝑒𝑛𝑒 𝐶𝑜𝑛𝑐𝑒𝑛𝑡𝑟𝑎𝑡𝑖𝑜𝑛
30𝑚𝐿
≤ 20 𝑝𝑝𝑚𝑣
Exceeding the lower limit of Equation 1 will decrease the accuracy and precision of the result.
Exceeding the upper limit will affect the sensitivity of the instrument and will cause the
instrument to under-estimate measurements for up to 24 hours.
A new calibration point may
be required.