# 2.2 Ultrasonic probe The instrument sends an ultrasonic signal. The transmission and reception of the signal through the pipe wall and interior fluid are performed through a piezoelectric ultrasonic probe and then transmitted through the ultrasonic signal. The resulting time differential is used to measure the flow. The distance between probes must be precisely calculated and the probes must be correctly placed to ensure measurement accuracy. This section describes the relevant wiring and installation precautions. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.lorric.com/qr/fu-tx310-ultrasonic-flowmeter-manual-en-v2/2-installation-method/2.2-ultrasonic-probe.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.