To begin the process of recording pressure data, simply press the Log Button. The FieldLab will either begin recording pressure data immediately with a Data Logging Test Mode, or it will give you instructions if you're calibrating a device with a Calibration Test Mode, depending on the type of Test Mode you have Activated.
Test Modes are pre-defined sets of operations for the FieldLab Pressure. The FieldLab Pressure comes with Test Modes pre-installed, but you can also create new and customize existing Test Modes with the FieldLab Desktop application, available as a free download here: Download FieldLab Desktop.