Using Software Options
Part # 910-250C
111
9.8.4.1 AUTOFREEZE
Spotweld reflections can be difficult to capture and maintain, especially when using a
captive water column transducer. The EPOCH 4PLUS AUTOFREEZE software option
provides an aid to the process of capturing welds for reference. This option automatically
freezes the live A-Scan display when an echo triggers an alarm condition in GATE 1 and/
or GATE 2. See Section 9.15for details regarding the AUTOFREEZE option.
Note: There are dangers to using AUTOFREEZE improperly that must be
understood to assure good results. The gate alarm that is to be triggered must
be set near to the maximum amplitude achievable from an echo (within 2%-
3%). If the gate level is set too low or the instrument gain too high, the
instrument will freeze echoes on the screen that are not representative of the
echoes that would appear without AUTOFREEZE. This can lead to operator
confusion and incorrect weld ratings by SWA.
To store the reference pattern for the UNWELD condition, follow the steps below:
1. Before storing the UNWELD condition, the instrument gain should be set so that the
first echo from the known GOOD weld condition is maximized at 80% FSH.
2. Couple to a known UNWELD condition.
3. Use the [FREEZE] key to freeze the live A-Scan after obtaining the best possible
reflection from the UNWELD nugget. If using the AUTOFREEZE software option,
this will happen automatically.
4. Once a satisfactory UNWELD ring-down pattern is established and frozen, press the
[2nd F] key followed by the [F1] function key to store the UNWELD reference.
5. A screen confirms the reference indication. Press the [F1] function key to accept and
store the weld reference or press the [F2] key to abort and begin again.
To store the reference patterns for the GOOD condition, follow the steps below:
1. Couple to a known GOOD weld condition.
2. Verify that the gain setting brings the first multiple to about 80% FSH.
3. Use the [FREEZE] key to freeze the live A-Scan after obtaining the best possible
reflect from the GOOD weld nugget. If using the AUTOFREEZE software option,
this will happen automatically.
4. Once a satisfactory GOOD weld ring-down pattern is established and frozen, press the
[2nd F] key followed by the [F2] function key to store the GOOD weld reference.
5. A screen confirms the reference indication. Press the [F1] function key to accept and
store the weld reference or press the [F2] to abort and begin again.
Note: If the EPOCH 4PLUS emits an audible tone after confirming either the
GOOD or UNWELD condition, this indicates the weld pattern is invalid,
and no reference template has been saved. Check the live parameters and
settings of the instrument and try to store the weld again.
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