What key data points are essential for calibrating an in-line inspection (ILI) tool after a run?

Calibrating an in-line inspection (ILI) tool after a run is crucial for ensuring the accuracy and reliability of the inspection data. Several key data points are essential for this process. First, accurate odometer readings are needed. The odometer measures the distance the tool travels through the pipeline. Comparing the odometer readings with known features in the pipeline (e.g., welds, bends, valves) allows for correction of any odometer drift or slippage that may have occurred during the run. Second, the tool's response to known features or defects in the pipeline is essential. If the tool passed over previously identified features or defects, the ILI data should be compared with the historical data to verify that the tool is measuring these features accurately. This helps identify any changes in the tool's sensitivity or calibration. Third, data from any external sensors that were used during the run is valuable. For example, if a GPS system was used to track the tool's location, the GPS data can be compared with the ILI data to verify the tool's positioning accuracy. Fourth, information about any operational events that occurred during the run, such as changes in flow rate or pressure, is important. These events can affect the tool's performance and may need to be accounted for during calibration. Fifth, the tool's internal calibration data, which is typically recorded by the tool itself, is also essential. This data includes information about the tool's sensor readings, battery voltage, and other parameters that can affect its performance. Sixth, field measurements taken at the excavation sites can be used to validate the ILI tool data. These measurements include the depth, length, and width of any metal loss features. Comparing these measurements with the ILI data helps to assess the accuracy of the tool's sizing capabilities. Using these key data points allows for a thorough calibration of the ILI tool, ensuring that the inspection data is accurate and reliable and provides a sound basis for integrity management decisions.