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Method Name: |
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Tunnel infrared thermography |
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Method Type: |
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Thermic Methods
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Assigned Problems: |
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Principle: |
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Determination of surface temperature of tunnel walls using infrared surface temperature measurements (thermal / infrared radiation). |
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Keywords: |
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Thermal imaging; infrared measurements; thermal and infrared radiation; temperature distribution; surface temperature of tunnel walls |
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Prerequisites: |
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- Existence of thermal contrast
- The field of view of radiation-measurement devices is limited.
- Thermal influences by cars and other heat sources.
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Resolution: |
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Radiation measurements (infrared thermography): Thermal resolution: usually ± 0,03 K; spatial/ geometrical resolution: usually 1,5 mrad
Typical depth of investigation: Surface |
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Expected Results: |
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- Measured parameter: Infrared thermography measures the intensity of the emitted electromagnetic radiation of a body
- Data analysis: The measured signal may be converted to temperature (emission coefficient/ emissivity must be known)
- Interpretation: Infrared thermography: Qualitative interpretation of relative thermal anomalies assuming that the measured signal (intensity of electromagnetic radiation) is correlated to the true temperature
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Combination with other Methods: |
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- Required additional information: camera information / setup (valuable wavelength), environmental conditions
- Related add-on information: optical scanning
- Independent additional information: georadar
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Operating Expense: |
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- Crew size: 1 key person; 1 - 2 assistants
- Acquisition speed: 3 - 6 km / h
- Processing: 1 - 2 days per measuring day
- Equipment rental costs: intermediate
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Parameters to specify: |
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- Instrument type
- Measuring grid / continuous measurements (acquisition speed!)
- Height of sensor / field of view
- Resolution and accuracy
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QC Documents: |
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- Field notes (e.g. all activities, effective time schedule, acquisition parameters)
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Products: |
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- Map / image (or profiles) of temperature distribution
- Interpretation
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