Handling Circuits with a large amount of low quality Measurements

At times it occurs that Corrosion calculation encounters problems due to a large number of time/growth errors and warnings. This situation is directly proportional to the quality of inputted readings.

Use case

The below example demonstrates a case where a large number of measurements have been taken in a relatively short time frame and inputted as is. Measurements have been taken some days apart and they also vary in value, causing both time and growth errors.

Take Note

While the issues outlined in this guide can be resolved by ignoring problematic measurements, this process can be time-consuming and may lead to unexpected penalties during corrosion calculations, depending on the scenario. Managing a large number of measurements that need to be ignored is a relatively complex task, and it may not be clear to every inspector working with such Circuits.

Resolving the issue

Simplified Case

Before proceeding you should pay attention to the following:

• Number of Circuits per Measurement set.

• Number of attachments per measurement.

When Measurement sets contain measurements for only one Circuit and when there are no attachments to the measurements, the following simple process can be followed.

• Export all measurements from the Circuit in question.

• Select only relevant measurements in the export file. Delete all other measurements in the export file.

• Delete existing Measurement sets (while paying attention to sets that contain measurements for multiple Circuits as noted above).

Take Note

Only INSP ADMIN is allowed to delete completed Measurement sets.

• Import only relevant measurements back into IMS and proceed with the Corrosion calculations.

Other Cases

Measurement sets can be exported individually. This may prove time-consuming in cases where there are many measurement sets.

Take Note

Currently, Measurement Set Simple does not contain the Measurement Notes. Therefore, if measurements have Notes entered, this information may be lost if the Full Measurement Set import type is not selected.

As an alternative, we propose using a custom query built as presented in the following screenshot.

The custom query results can be exported into an Excel file. The exported file is essentially equivalent to the simple Measurement import type, but with Notes and CML RWT columns added. It should be imported as the Measurement Set import type to allow for the import of Measurement Notes.

Working with the export file

The entire Excel table should be sorted based on Equipment ID, Circuit ID, CML ID, PDMP Measurement Point, PDMP MatrixLocation, Measurement Date, and WT Measurement. Doing so allows for measurements to be grouped per PDMP, and it sorts measurements by Measurement date, older to newer, larger WT to smaller WT.

In the following steps, the inspector needs to:

• Determine the first/baseline reading.

• Determine relevant readings that are sufficiently spaced out from previous readings.

• Remove readings that will cause growth and time errors.

In the following example, we can see that the inputted readings are too close together (less than 6 months apart) and that there is also an increase in the measured material thickness. The objective here is to determine which measurements are valid and to remove those that are not. When the process has been completed, the Measurement set file can be imported.

Take Note

IMS may not handle multiple measurements for the same PDMP entered on the same date as expected. It is crucial to ensure that only one WT measurement is recorded per PDMP for each measurement date.