> For the complete documentation index, see [llms.txt](https://docs.lorric.com/qr/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.lorric.com/qr/fu-tx310-ultrasonic-flowmeter-manual-en-v2/2-installation-method/2.4-installation-check/2.4.2-q-value.md). # 2.4.2 Q value The Q value represents the received signal quality and can be regarded as an indicator of signal-to-noise ratio (SNR). The value is displayed at the lower right of the display interface. The value ranges between 0 and 100%. Under normal conditions, the Q value should be > 60%. The higher the Q value, the better the signal quality, and the more reliable the measured value. A Q value of less than 10% will not be measured. Try the following solutions: ● Sometimes the RSSI value is high, but a low Q value may be displayed due to slight distance, angle, or other errors in the probe. If the Q value is low, try to adjust the distance and angle of the probe slightly. ● If the pipe surface is rough, smooth it and confirm that the probe can completely adhere to the pipe surface with no gaps. ● If the coating provided by the coupling agent isn’t smooth, recoat to provide a smooth surface. ● If the pipe surface has impurities, dirt, or grime, the probe should be moved to another location. ● If surrounding equipment causes electromagnetic interference, change the installation location or strengthen shielding. ● If the fluid flow field is unstable, change the installation location. ● If the pipe diameter is too large, set up the probe in the Z​ configuration. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://docs.lorric.com/qr/fu-tx310-ultrasonic-flowmeter-manual-en-v2/2-installation-method/2.4-installation-check/2.4.2-q-value.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case. 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.