Why do I have to wait to use my digital breathalyser after turning it on?

When you first turn your breathalyser on it will need to warm the units sensor up to approximately the same temperature as your breath, which is around 34 degrees celsius. Times will range from 5 – 45 second depending on the quality of sensor that you have purchased. This needs to happen to ensure accuracy of the reading. If the warm up time becomes very slow then this is an indication that there is residue alcohol build up on the sensor and it is time for recalibration.