The objective of the present activity is to design, manufacture and test a breadboard model and an engineering model of a compact Quartz Crystal Microbalance (QCM) measuring system. The Contamination Assessment Microbalance (CAM) is a low-mass (< 1 kg) device which will monitor in-orbit contamination of sensitive surfaces and payloads on ESA’s future satellites. QCM were used in the past to monitor contamination in different ESA or NASA space missions. Typically they used sensors manufactured and sold by US companies, only few were customized European sensors. In this Tender, ESA gives several requirements in terms of performance, part procurement, design, environmental. While the environmental, the part procurement and the design requirements can be considered standard, instead there are some performance requirements that are extremely challenging. Maybe the most important example is the temperature measurement accuracy and the related active thermal control. At present, even US companies producing QCM for Space applications are not offering products with similar performances. Here, the Tenderer propose a novel approach to monitor the quartz crystal temperature and to heat the crystal itself by means of a built-in resistive deposited thin film.