Generally, it takes between 30 to 60 seconds for the NC° Thermometer Gen1 to measure your temperature. The thermometer will beep to indicate that the measurement has stablized and is ready to record.
To make sure that you are measuring correctly and that your thermometer is working as it should, we always recommend completing the Measuring Training in the app when you get started with Natural Cycles, which you can find under the top menu > My device.
We recommend reading the instructions listed in this article before completing the Measuring Training.