Matsushita Carbon Resistors as Thermometers for Use at Low Temperatures and in High Fields(Physics)

A survey has been made of the properties of 1/8 W composite resistors made by the Matsushita Electric Ind. Co. Ltd. to determine whether they might be suitable as secondary thermometers in the low‐temperature region. From the measurements of resistance vs temperature, between 105 °C and 40 mK, it is confirmed that the grade ERC‐18SGJ resistors in various nominal room‐temperature resistance values from 20 to 510 Ω are suitable in very low ‐temperature work, and that resistors in the nominal resistance range 20–100 Ω are the most suitable for work down to several tens of mK. An advantage of Matsushita resistors as thermometers in the low‐temperature region is that they are available in 1/8 W size, and we can choose their nominal resistances from 10 Ω to several hundreds of ohms in steps of a few ohms. The magnetoresistance of Matsushita resistors having nominal resistances of 30 to 510 Ω has been measured in fields up to about 80 kG at temperatures between ∼4.2 and ∼1.5 K. It is shown that the percentage ch...