Block mass-flow sensors

Other instruments include the Calvet microcalorimeters [113], some of which can also run in the scanning mode as a DSC. These are available commercially from SETARAM. The calorimeters exist in several configurations. Each consists of sample and reference vessels placed in an isothermally controlled and insulated block. The side walls are in intimate contact with heat-flow sensors. Typical volumes of sample/reference vessels are 0.1 to 100 cm3, The instruments can be operated from below ambient temperatures up to 300°C (some high temperature instruments can operate up to 1000°C). The sensitivity of these instruments is better than 1 pW, which translates to a detection limit of 1 x 10-3 W/kg with a sample mass of 1 g. 

Figure 7. Schematic diagram of a flow channel of height h with a blocking cylinder of diameter d placed in the center (b = h/2). The working electrode (labeled mass-transfer sensor) is placed a distance a downsteam of the cylinder center. The counterelectrode (not shown) is located on the opposite wall of the channel.

All three of these PhD theses contain sections on the theory of operation of each component of the mass/heat-flow sensor and experimental details such as block diagrams of the apparatus, sample preparation, data acquisition and control, calibration, and data analysis. 

Fig. 10 Above chemical structure of the PEO-PCl-ssDNA conjugate (with the 22-mer oligonucleotide sequence arm ) and representation of a DNA micelle. Below DNA-controlled attachment of block copolymer micelles on surfaces monitored by measuring the time-dependent frequency and dissipation changes induced by mass adsorption on the QCM sensor in the flow mode. Step 1 addition of the anchor -thiolated oligonucleotide. Step 2 addition of the micelles bearing the linker oligonucleotide, followed by rinsing. Step 3 treatment with the as-arm oligonucleotide (competitive displacement to detach the micelles) [84] (figure adapted with permission of Wiley-VCH)...

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