Detector Systems
Thermal conductivity detector (TCD)
Optimizing performance
The following sections aid in choosing operating parameters to obtain optimal TCD performance.
Temperature
TCD sensitivity increases as the temperature difference between the detector filament (automatically set) and the surrounding detector body (chosen detector zone temperature) increases.
To minimize changes in detector sensitivity with different operating temperatures, filament temperature is maintained at a relatively constant difference above detector operating temperature. Filament resistance (proportional to temperature) is monitored, and power is adjusted as needed to maintain the filament at constant temperature.
Figure
500 |
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400 | Filament Temperature | 50 C |
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Filament 300
Temp
( C)
200 | Block Temperature |
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100 | 135 C |
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0 |
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0 | 100 | 200 | 30 | 400 |
| Detector Temperature (Body 0 |
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| Temp) | C |
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Filament Temperature versus Detector Block Temperature
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