Answer :
Final answer:
The main disadvantages of using an electronic leak detector are the high cost of the equipment, the need for specialized training to operate them, and the requirement for frequent calibration.
Option 4 is correct.
Explanation:
A disadvantage of using an electronic leak detector is the high cost associated with the equipment. Electronic leak detectors can be very expensive, which is a significant drawback for their use.
Furthermore, these devices require a skilled professional for operation and accurate analysis, adding to the overall expense due to the need for specialized training. Regular calibration is also necessary to maintain their accuracy, which may be seen as another disadvantage due to the additional time and resources needed.
