The AER 5300 continuously monitors the environment for airborne, long-lived alpha and beta emitters. The devices are used in nuclear facilities, in the NORM industry, in mining operations and in nuclear medicine (e.g. in accordance with DIN ISO 16639 / ISO 20044 / VDE 0493-1-6639 etc.). The aerosols are collected on a filter with automatic replacement and analysed spectroscopically. The background signal caused by radon and ambient gamma radiation is fully compensated for. The device is equipped with an easy-to-decontaminate stainless steel housing, which can be mounted either on a wall bracket or on a trolley. The air inlet, in the form of a flange (KF/DN16), is located on the top of the housing. The AER 5300 has been designed for maximum maintenance-free operating period. The 1200 mm² semiconductor detector allows a large active filter area, which significantly extends the filter’s service life. The length of the filter tape is designed to allow for one year of operation with a daily filter change. Thanks to flow control via a frequency converter, the pump operates well below its rated power, significantly reducing abrasion and noise emissions. The flow rate of the AER 5300 is continuously controlled and can be adjusted over a wide range. In addition to maintaining constant separation conditions, it is easy to adapt the unit for isokinetic sampling. If the unit is to be connected to a central vacuum supply, a version with a servo valve for controlling the flow rate is available. Access to the belt filter is quick and easy. This allows activated filters to be easily cut out of the filter belt for any laboratory analysis. A new filter belt can be inserted without the need for tools. A version with a fixed filter is also available. To ensure maximum IT security, the AER 5300 operates using a microcontroller and proprietary firmware. The device is ready for use immediately after being switched on. A wide range of interfaces allows for easy connection to various host systems. All relevant parameters and events are monitored and recorded by the device. The flexible alarm system provides immediate warning in the event of limit violations or faults.