Cathodic Protection Tester Practice Exam

Which pipe locator requires a wire connection to the structure for frequency pickup?

1. Inductive pipe locator

2. Conductive pipe locator

3. Active pipe locator

4. Passive pipe locator

The correct answer is: Conductive pipe locator

A conductive pipe locator is designed to work by establishing a direct electrical connection between the locator and the pipeline or structure being located. This connection allows the device to inject a signal into the pipeline, which creates an electromagnetic field around it. The locator then picks up the frequency of the signal by detecting the electromagnetic field, thus allowing the operator to accurately trace the path of the pipeline. In contrast, inductive pipe locators utilize magnetic fields generated by an alternating current, often without any direct connection to the pipeline, relying instead on the natural electromagnetic field. Active pipe locators may also transmit signals and can function similarly to conductive locators but do so in a broader context that may not require a direct wire connection. Passive locators usually detect existing electromagnetic signals emitted by the pipeline itself, without any need for connectivity. Therefore, the definition and working mechanism clearly align with the conductive pipe locator's requirement for a wire connection.