> For the complete documentation index, see [llms.txt](https://docs.rapt.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.rapt.io/equipment/rapt-laser-level-sensor/laser-array-guide.md).

# Laser Array Guide

KL49344 RAPT Laser Level Sensor | Laser Array Guide

When using the RAPT Lasrer Level Sensor, to get the most reliable reading
 from the surface of the
 liquid/solid it’s best that the *entire*
 laser array falls onto the *surface* of
 the product being measured
 (rather than the wall of the vessel).

The image below shows how the
 laser array fires out from the base
 of the unit.

<figure><img src="https://570278281-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FUqN4sW0x2s4yh6iiT8NN%2Fuploads%2FexKlF4M9A0uUPtLuNUCd%2FLaser%20Level%20Sensor%20Array.jpg?alt=media&amp;token=348acf78-a337-409f-a5a4-24550657d504" alt=""><figcaption><p>RAPT Laser Level Sensor - Array Visualisation</p></figcaption></figure>

For unusually shaped vessels or vessels that are not a standard cylinder, such as conical tanks, the laser will start to
&#x20;give less accurate readings as the
&#x20;the majority of the laser falls onto
&#x20;the *walls* of the conical tank rather
&#x20;than onto the liquid itself.
&#x20;This will generally happen as the liquid level is quite low in the vessel. For example, in the BrewBuilt 144L
&#x20;conical fermenter the sensor will
&#x20;give poor accuracy in the last 5L
&#x20;of tank volume and may be
&#x20;undetectable.