Final answer:
The question relates to Engineering standards or procedures for inspecting railway tracks to ensure their structural integrity and safety. Measures such as meters or kilometers are used in the inspection process to assess various aspects of the tracks.
Step-by-step explanation:
The question 'Inspection of track rails is (3-168)?' likely pertains to standards or procedures for the inspection of railway tracks, which is a topic within the field of Engineering, specifically related to transportation or civil engineering. Track inspection is crucial for ensuring the safety and reliability of rail transportation systems.
When performing track rail inspections, engineers and inspectors seek to identify any issues that may compromise the structural integrity of the rail tracks. This can include checking for cracks, deformations, and wear that occur over time due to the stress of passing trains. They may use a variety of tools and technologies, including visual inspections, ultrasonic testing, and measurement gauges. The standards for inspection often require detailed recording and monitoring, which can include the use of numerical codes or references like '3-168' to categorize conditions or specific parts of the inspection protocol.
Example 3.1.3.3 from the referenced material indicates a question about a unit of measurement, suggesting that measurements are an integral part of the inspection process. In the context of track rails, engineers would commonly use meters or kilometers for linear measurements, depending on the scale, while for smaller features, they might use millimeters or centimeters.