Explain what types of pipeline materials and media are required for the transit time clamp on type and the insertion type from the propagation characteristics of ultrasonic waves.

1) Clamp On Sensor The pipeline materials that can meet the requirements are quite diverse, including various metal pipelines, various engineering plastic pipelines, and other pipelines with uniform and dense materials. Regardless of the type of pipeline, the pipeline material must be uniform and dense, and have good sound conductivity. There should be no voids in the material, and the pipe wall should be smooth and flat. If the pipeline has a lining, the material type of the lining should meet the requirements of our company’s instrument and should be well bonded to the pipeline without any gaps. The measurement medium is a single-phase liquid that does not contain too many and too large bubbles and solid particle impurities, and the medium temperature is within the range of -35～85°C (standard type) or -35～200°C (high-temperature type).

2) Insertion Type Sensor There are basically no requirements for the pipeline material. For weldable metal pipelines, they can be directly welded for installation, and for other metal and non-metal pipelines that cannot be welded, they can be installed by means of a hoop. The measurement medium is a single-phase liquid that does not contain too many and too large bubbles and solid particle impurities, and the medium temperature is within the range of -35～85°C (standard type) or -35～150°C (high-temperature type). In addition, when the insertion type sensor is used for measurement, the toxicity of the medium, the corrosiveness of the medium to the probe, and the working pressure of the medium ≤ 2.5MPa (1.6MPa) should also be considered. When the medium is relatively dirty and the contaminants are likely to adhere to the probe, the probe should be cleaned regularly.