A system and method for surface characterization of a porous solid or powder sample using flowing gas include mass flow controllers configured to deliver a controllable mass flow of a carrier gas and adsorptive gas to vary concentration of the adsorptive gas flowing through at least one measurement channel containing a sample cell. A concentration detector downstream of the sample cell provides a signal indicative of the adsorptive gas concentration to a controller that determines the amount of adsorptive gas adsorbed and/or desorbed to characterize the surface area, pore volume, pore volume distribution, etc. of the sample material. The detector may include a housing, heat exchanger, thermal conductivity detector, and a temperature regulator.

The present invention relates to methods and systems for testing for the presence of a material such as one or more analyte types within a sample and more particularly, for improved single enzyme-linked immunosorbent assay (sELISA) testing as well as other variants of single-enzyme linked molecular analysis (SELMA). Background and false positives are reduced due to the presence of at least two detection cycles where each detection cycle comprises the steps of a) triggering a signal from captured and labelled analyte(s), b) recording of the number and positions of capture sites exhibiting a signal from the captured and labelled analyte(s), c) and before a further detection cycle is performed, deactivation of signal(s).

Technical equilibrium can be used to measure a single gas isotherm in a relatively fast and continuous manner rather than, for example, in a batch manner. Further, an expansion vessel can be used for successive desorption a multicomponent gas in combination with determining the composition of the multicomponent gas in combination with a calculation that provides both qualitative and quantitative information about the multicomponent gas. Moreover, a multicomponent gas can be flowed through an adsorbent bed and the and the flow of the multicomponent gas flow is shut off and isolated when equilibrium is reached.