The testo 6651 rises to special challenges. Paired with the testo 660x probe series, it becomes the top choice for demanding air conditioning technology and a wide range of other applications.

The testo 6621 high-performance measurement transmitter is a dependable solution for building air conditioning applications. Offering excellent accuracy, long-term stability, and reliability, this transmitter meets the rigorous standards of building automation, helping to optimize efficiency and reduce costs.

The testo 6631 temperature and humidity transmitter is specifically designed for use in greenhouses and laboratories, providing reliable monitoring of critical environmental conditions essential for biological research.

The HF5A-series is our latest advanced transmitter, compatible with HC2, HC2A, and RMS probes for humidity, temperature, and differential pressure.