In a freeze-drying process, the product temperature is the most important critical quality attribute. A combination of process and product parameters, such as shelf temperature, chamber pressure, product resistance, container geometry, radiative heat transfer, and the physicochemical state of the product, determines it. Tempris sensors are wireless and battery-free, designed to monitor the product temperature. They provide real-time data on product temperature on all scales of freeze dryers, even in combination with automatic loading systems. This helps to overcome the challenge of keeping all product units within the batch at a target product temperature throughout the process.