Ruthenium oxide temperature sensors are thick-film resistors, with most models suitable for use in magnetic field applications. These composite sensors consist of bismuth ruthenate, ruthenium oxides, binders, and other compounds that allow
them to obtain the necessary temperature and resistance characteristics. Each Lake Shore Rox™ model adheres to a single resistance versus temperature curve.
The RX-102A (1000 Ω at room temperature) is useful down to 50 mK and has better interchangeability than the RX-202A as well as low magnetic field-induced errors below 1 K.
The RX-202A (2000 Ω at room temperature) has a 4× improvement in magnetic field-induced errors over other commercially available ruthenium oxide temperature sensors with similar resistances and sensitivities. Most ruthenium oxide sensors
have a maximum useful temperature limit well below room temperature, where the sensitivity changes from negative to positive. The RX-202A, however, is designed to have a monotonic response from 0.05 K up to 300 K.
The RX-103A (10,000 Ω at room temperature) has a unique resistance and temperature response curve combined with low magnetic field-induced errors and is the best choice for interchangeability from 1.4 K to 40 K.