ABSTRACT
Analternatedesignusingtwopushrods(suchasthatusedby ThetaIndustries)isshowninFigure7.4.Inthisconfiguration,
theexpansionorcontractionofthesampleismeasuredrelative totheexpansionorcontractionofaNISTreferencematerial, sincetheexpansion/contractionofthereferenceshiftsthelocationoftheposition-transducerhousing.Theadvantageofthis designisthattheexpansionbehaviorofthereferencematerial isknownprecisely.Withasinglepushroddevice,theexpansionbehaviorofthecasingmaterialmaynotbeasaccurately documented.
