Enter historical ultrasonic thickness readings to compare wall thickness over time, identify the measured trend and estimate an average thickness-loss rate.
| Inspection Date | Thickness | Note | |
|---|---|---|---|
| Date | Thickness | Change | Interval | Rate |
|---|
A thickness trend compares repeated ultrasonic thickness measurements taken at the same or comparable monitoring location. The measurements are arranged chronologically so that changes in wall thickness can be evaluated.
This analyzer uses the first and latest valid measurements for the headline historical loss rate while also showing the change between individual readings.
A single UT reading describes thickness at one inspection point and one moment in time. A sequence of readings provides additional information about how that measured thickness has changed.
Historical records are especially useful when readings are taken at established thickness-monitoring locations using consistent inspection procedures.
The overall average rate uses the first and latest measurements across the entire period. Individual interval rates compare each consecutive pair of readings.
These values can differ substantially when the deterioration rate has changed over time. An irregular history should therefore not be reduced to a single number without reviewing the individual measurements.
The analyzer can compare the latest measured thickness with an entered minimum thickness value.
A positive margin means the latest measurement is above the entered threshold. A zero or negative margin indicates that the latest reading is at or below the entered threshold and requires appropriate engineering or inspection review.
When the historical trend shows a positive thickness-loss rate, the analyzer can calculate a simple projected time to the entered minimum thickness.
This is a mathematical projection based on the historical average rate. Actual deterioration can accelerate, slow down or change mechanism, so the projection should not be treated as a guaranteed service-life prediction.
Engineering decisions require component-specific design information, inspection quality, applicable standards and appropriate professional assessment.
What does a UT thickness trend show? It shows how measured wall thickness changes across historical inspection dates.
How is the average thickness-loss rate calculated? The total measured thickness reduction between the first and latest readings is divided by the elapsed time.
Why can UT readings increase between inspections? Measurement positioning, surface condition, calibration, temperature and other inspection factors can cause a later reading to be higher.
Can this trend predict future corrosion? It can provide a simple historical trend, but future deterioration may not continue at the same rate.
What if the historical trend is irregular? Review the individual measurements, inspection conditions and measurement locations before interpreting the trend as actual material deterioration.
Does the projected time to minimum thickness mean guaranteed remaining life? No. It is a mathematical projection based on the selected historical rate and should not be treated as a guaranteed service-life prediction.