Sampling calibration setup

Figure 2. Calibration setup for personal sampling pump with cyclone collection...

Accessibility to Cu sites was determined by temperature programmed desorption of NO (NO TPD), using an experimental setup similar to that used for TPR, except the detector was a quadrupole mass spectrometer (Balzers QMS421) calibrated on standard mixtures. The samples were first activated in air at 673 K, cooled to room temperature in air, and saturated with NO (NO/He 1/99, vol/vol). They were then flushed with He until no NO could be detected in the effluent, and TPD was started up to 873 K at a heating rate of 10 K/min with an helium flow of 50 cm min. The amount of NO held on the surface was determined from the peak area of the TPD curves. 

These setups have been chosen to measure abundances of iron peak, a-elements and neutron-capture elements. In parallel, a subset of 14 stars has been observed with the high resolution spectrograph UVES (R=48000) to serve as calibrators for the GIRAFFE sample. 

This brings us to the subject of standards. In this connection a standard is simply a sample with a known hydrogen content that is used for convenience to calibrate the overall counting efficiency of a particular setup, i.e., to determine the factor AfICalibration standards must be stable under irradiation. While plastic foils of known composition can be used if precautions are taken (Rudolph et al., 1986), their intrinsic instability makes them unsuitable. The standard used by most groups is hydrogen-implanted silicon, which has the advantages that it is easily prepared, the implanted dose can be measured to 5%, and the amount of implanted hydrogen is stable at room temperature and under MeV 15N irradiation, as discussed later. 

Figure. 3.20 Colocation of correct upstream sampler and PAT sensor, shown here for a recirculation loop configuration (right). The PAT sensor is deployed in upstream small-diameter piping with a field of view matching as best possible the same stream segment which is being sampled for reference analysis. This setup allows for reliable multivariate calibration because of the colocated [X, f] modalities.

The experimental setup for diode-laser sensing of combustion gases using extractive sampling techniques is shown in Fig. 24.8. The measurements were performed in the post-flame region of laminar methane-air flames at atmospheric conditions. A premixed, water-cooled, ducted flat-flame burner with a 6-centimeter diameter served as the combustion test-bed. Methane and air flows were metered with calibrated rotameters, premixed, and injected into the burner. The stoichiometry was varied between equivalence ratios of = 0.67 to... 

To maintain consistency of statistical analyses, an identical microtiter plate setup was used by all participants, and all samples were analyzed in an identical manner. Both raw data and pretreated data from analyzed samples were submitted to OpdenKamp Registration and Notifieation for statistical evaluation. Data pretreatment consisted of all necessary calculations to convert the luminosity readings as submitted by the participating laboratories to effective dioxin-receptor activity (pM 2,3,7,8-TCDD TEQ). In addition to the analysis results of the defined samples (phase 1), the cleaned sediment extracts (phase 2), and the complete sediments (phase 3), all participants also submitted the results of the complete 2,3,7,8-TCDD calibration curves for statistical evaluation. 

Then, the particular experimental setup to prepare a set of calibration samples can be deployed following any of the procedures explained in Chapter 2 (experimental design and optimisation). We found it very useful to set a Plackett-Burman design at each level of the analyte concentration but, of course, other possibilities exist. The important point here is to obtain a sufficiently large number of calibration samples so that any (reasonable) combination of concomitants and analyte that might appear in the problem samples has been considered previously in the calibration. This is the general rule that "you should model first what you want to predict afterwards [18]. 

Fig. 4. Measurement sequence of third-harmonic generation in solution. A THG experiment of fused silica in vacuum yields the calibration of the whole setup. The same fused silica plate measured in air leads to the air contribution, which is afterwards taken into account in the THG measurements of the various sample concentrations...

It has the so-called scanning setup, with a Huber goniometer and a high-resolution microscope located at a calibrated distance from the beam position, so that a specific point can be selected on the sample and automatically transferred into the beam. 

FFF calibrations are universal in the sense that calibration constants apply to all other FFF setups under a wide range of experimental conditions [113] which are somewhat different from SEC as explained below. For characterizing molecular mass distributions with SEC, the calibration constants must be determined empirically for a whole set of standard samples. FFF channels are also calibrated empirically with standards for polymer-solvent systems where the Mark-Hou-wink coefficients for the dependence of the transport coefficients on M are un-... 

BENDING OF A BEAM. The complex dynamic Young s modulus can be determined from the forced, non-resonant oscillations of a single or double cantilever beam. The apparatus considered in this paper is the Dynamic Mechanical Thermal Analyzer (DMTA) (6), manufactured by Polymer Laboratories, Inc. Figure 3 shows the experimental setup for the single cantilever measurement. A thin sample is clamped at both ends. One end is attached to a calibrated shaker through a drive shaft. 

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