Calculating A And C Values - Olympus EPOCH 650 User Manual

DMTA-10055-01EN, Rev. A, February 2015
11.4.5

Calculating A and C Values

When a gated echo whose peak is below 100 % FSH is present, the EPOCH 650
ultrasonic flaw detector automatically calculates the A and C values necessary to
provide a D indication rating value. For A, the EPOCH 650 automatically calculates
the required dB value to bring the gated echo to reference height. To calculate C, the
EPOCH 650 uses the data in the sound path calculator to generate an attenuation
factor.
In order for this calculation to be accurate, you must enter the correct thickness
for the test piece.
By pressing SAVE, you can now save the data for this discontinuity in the EPOCH 650
data logger. For general data logger information, see "Data Logger" on page 187.
At the bottom of an ID saved with AWS D1.1 active, you can see the values for A, B, C,
and D. This data can be viewed in the file review window.
You can also choose to see live A, B, and C values displayed in the reading
measurement boxes at the top of the screen.
While using the EPOCH 650 and the AWS D1.1 software feature, you must
account for any inspection conditions that could cause variations in the displayed
indication rating (D value), and properly interpret the meaning of echo
indications and reported D values corresponding to these indications.
11.5 API 5UE
The API 5UE software option for the EPOCH 650 ultrasonic flaw detector is intended
to assist with performing inspections in accordance with the American Petroleum
Institute (API) Recommended Practice 5UE. This practice was developed specifically
for OCTG manufacturers to inspect and characterize inner-diameter (ID) cracking in
newly fabricated pipe. The API 5UE code uses two crack sizing methods to
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