Thee are several reason for a channel to lose its signal completely.
- BNC signal cable is damaged. The connectors can also contain too much dirt or corrosion.
- Coupling hoses for the test head can be fully or partially clogged.
- Transducer face can be covered with dirt or grease.
- Transducer could have sustained physical or thermal damage.
- Entire transducer assembly was hit, and displaced.
- In extreme cases the UT board for that specific channel could have sustained electrical damage from the mill.
Here are a few tips to troubleshoot the problem, always over the calibration stand not over the product:
- Check the cable by replacing it with a new one.
- Uncouple the coupling hoses and check for smooth laminar flow from both hoses.
- Clean transducer face with a smooth clean cloth.
- A low or missing main bang signal can be a clear indication of transducer damage.
- The fork holding the transducer should be perpendicular to the product to be tested and aligned with the opposing transducer. Remove brass tip set screws and check for damage then tighten, ensuring correct alignment.
- In the case where the UT board was damaged from excess electrical signal on the pipe being tested, usually both channels that UT board powers will be damaged.
- After all the above troubleshooting was performed, swamping the BNC cable to the adjacent CH (ex: CH1 move to CH3) can provide more clues as to the nature of the damage. If the problem is transferred to the new channel, then the issue is likely downstream from the BNC cable to transducer and its assembly. If the problem isn't transferred to the new channel, then the issue is likely upstream from the BNC Bulkhead Connector to UT computer.
If you have more questions or concerns or any other issues, please contact our support at the link below or create a ticket.