# Buttons ## The four buttons: Measure Stop Empty Clean BactoBox® has four buttons on the top side:

`Measure` (C), `Stop` (D), `Empty` (E), and `Clean` (F)

### Start program When you press Measure, Empty, or Clean, BactoBox® starts the corresponding program. {% hint style="info" %} #### BactoBox® helps you avoid common mistakes For example, if you press Clean but there is no flow cell in the device, BactoBox® does nothing. This avoids leaks. Likewise, if it has been a long time since the last clean, BactoBox® may block the *Measure* program until you run *Clean*. This reduces instrument background when you measure your samples. {% endhint %} #### The Empty button If BactoBox® stops unexpectedly during a measurement, it still has liquid inside. Use the Empty button to drain the liquid from the flow paths into the vial. {% hint style="success" %} ## You rarely need to press the Empty button The Empty button is only there for special cases. E.g., if the power goes or if an error occurs. If BactoBox® detects liquid inside, it prompts you to press Empty. You don't even need to remember this yourself, BactoBox® helps you out. BactoBox® even remembers this across a power off. {% endhint %} ### Stop program When you press the Stop button, BactoBox® immediately stops the current program. If there is liquid in the flow paths, BactoBox® empties the flow paths first. {% hint style="success" %} ## Give it time to empty the flow paths Leave the tubing kit in the vial until the *emptying* phase is done. This ensures that *all* liquid goes back into the vial. {% endhint %} ## Navigation mode: OK ← ∨ ∧ Certain screens in the [user interface](https://help.sbtinstruments.com/encyclopedia/software/user-interface) require additional input. E.g., to navigate the [menu](https://help.sbtinstruments.com/encyclopedia/software/user-interface/menu-system) or to set the time and date. For this purpose, BactoBox® automatically remaps the buttons to *navigation mode*. When there is a OK ← ∨ ∧ bar in the bottom of the screen, you know that the buttons are in navigation mode: