Q meter measurements up to 260 MHz

The results indicate that the proposed dielectric measuring system can be successfully used to measure ε´ (±1%) and ε" (±5%) of moderately low loss, low dielectric constant disk shaped specimens/and that the method can he adapted to low temperature measurements. A suggested low temperature design is shown in Figure 3. The important considerations are minimum lead length, rigid ceramic mounts between the holder and spacing measuring assembly, plastic foam heat insulation, and a fast and convenient way of inserting and removing the specimen, the reference ball gauge and the temperature measuring thermocouples. Cooling will be accomplished by passing dry nitrogen gas, precooled to a constant temperature, through and around the holder. At -200°C there will be about 4 watts of heat entering the holder chamber, which amount would seem acceptable. No additional problems are anticipated. A more sensitive micrometer system should result in increased precision even at low temperatures.