ULTRASENSITIVE RATIOMETRIC CAPACITANCE DILATOMETER AND RELATED METHODS

摘要

An ultrasensitive ratiometric capacitance dilatometer and related methods are described. The dilatometer provides a capacitance measurement based on a ratiometric capacitance, or the capacitance ratio measured between two or more parallel plate capacitors of the dilatometer. In this regard, an absolute capacity bridge is not required, and even more advantageously, the effects of adsorbed gas are greatly reduced compared to conventional dilatometers. The ratiometric capacitance dilatometer provides a symmetrical configuration, which reduces the effects of temperature gradients. Moreover, certain embodiments provide a “v-groove design”, wherein a first parallel plate capacitor forms an angle with a second parallel plate capacitor of the dilatometer along a key centerline of the dilatometer cell, which improves manufacturability due to simpler grinding, metalizing and assembly.

主权项

1. An ultrasensitive ratiometric capacitance dilatometer cell, comprising:
a first cell portion configured to nest with a second cell portion to define a cell volume, the first cell portion and second cell portion being separated by a gap extending therebetween; a first parallel plate capacitor comprising:
a first conductive plate coupled to the first cell portion, anda second conductive plate coupled to the second cell portion,wherein the first conductive plate is configured to at least partially overlap with the second conductive plate; a second parallel plate capacitor, the second parallel plate capacitor being formed between the first and second cell portions; and a channel extending across the gap from the first cell portion to the second cell portion, the channel comprising:
a first wall being coupled to the first cell portion; anda second wall being coupled to the second cell portion, the second wall configured to oppose the first wall;the first and second opposing walls being configured to receive a sample therebetween; wherein the dilatometer cell is configured to measure a ratiometric capacitance change between the first and second parallel plate capacitors as the sample varies in size between the first and second walls.