Which of the following is an example of a validation tester?

A validation tester is a sophisticated tool designed to assess the performance and compliance of cabling installations against established standards for voice and data transmission. The Fluke Networks DTX is a prime example of a validation tester, as it is capable of conducting comprehensive tests that include the verification of cable performance parameters such as attenuation, NEXT (Near-End Crosstalk), and return loss. This type of testing ensures that a cabling installation meets the required specifications for network performance and reliability, which is crucial for effective communication in any premises cabling setup.

The other options listed do not fulfill the criteria for a validation tester. A simple wiremap tester primarily checks for continuity and verifies that the correct pairs are connected in a cable, but it lacks the capability to measure performance metrics required for validation. A multimeter is useful for measuring electrical characteristics but does not specifically test network cabling performance. An Ethernet cable length tester measures the length of a cable but does not evaluate its performance metrics, making it unsuitable as a validation tester. Thus, the Fluke Networks DTX stands out as a comprehensive and capable validation testing tool.