Acquisition time setting

According to what has been stated above, good results have been obtained as a result of a spectrophotometric technique that entails a colored tracer. Two measuring probes are set up one at the inlet and the other at the outlet of the device. The acquisition time is set to 0.12 s. The operating protocol adopted during RTD experiments is as follows ... 

The most popular, and also a very accurate, experimental method for measuring nonselective spin-lattice relaxation-rates is the inversion recovery (180°-r-90°-AT-PD)NT pulse sequence. Here, t is the variable parameter, the little t between pulses, AT is the acquisition time, PD is the pulse delay, set such that AT-I- PD s 5 x T, and NT is the total number of transients required for an acceptable signal-to-noise ratio. Sequential application of a series of two-pulse sequences, each using a different pulsespacing, t, gives a series of partially relaxed spectra. Values of Rj can... 

We should decide in advance the digital resolution at which we wish to acquire a spectrum and then set the acquisition time accordingly. The acquisition time AT (that is, the product of the number of data points to be collected and the dwell time between the data points) is calculated as simply the reciprocal of the digital resolution ... 

The first and last data sets, A and D, are thus recorded using an opposite undulator configuration (u, d ) to the second and third, B, C (uT,d ). While this sequence is recorded the stored beam current will decay, and with it the light intensity, but this sequencing is intended to balance out the data acquisition time spent in either undulator configuration. At the end, equal counts are obtained in each data set, and for each undulator configuration. 

A nominal spatial resolution of 50 pm was set, acquiring an echo window 20-ps long. The position of the sensor was moved in steps of 25 pm requiring 160 points to cover the complete sample thickness. Using 512 scans per point and a repetition time of 150 ms the acquisition time per point was 75 s. 

This parameter is not normally set directly but is a function of the values that you set for spectral width and number of points. The narrower the spectral width, the longer will be the acquisition time and the greater the number of points, the longer the acquisition time. 

In order to more accurately identify the contaminant, and to determine if the fuel delivery system module filter was the source, both materials were analyzed using 1H NMR spectroscopy Samples were dissolved in a 60 40 mixture of deuterated chloroform/triflouroethanol. It should be noted that the amount of contaminant available for analysis was quite small, so for this sample, the NMR spectral acquisition time was set to 1 h in order to record a spectrum of adequate signal-to-noise ratio. 

The acquisition speed is, as for the FTICR, resolution dependent. With Thermo Fischer Scientific s orbitrap the desired mass resolving power can be selected. With the lowest setting (7500 FWHM) the acquisition time for one ion injection is 0.3 s and with the highest setting (100,000 FWHM) it is 1.9 s. 

Why then, is such a complicated and expensive set up necessary AMS combines mass spectrometric features with efficient discrimination of isobaric and molecular interferences. Therefore, it can detect and quantify atomic species of very low abundance. In the case of 14C dating, before AMS was utilized, about 1 g of carbon was needed to date an archaeological item. One gram of fresh carbon contains about 6 x 1010 14C atoms, of which 14 decay per minute. To get 0.5% statistical precision using decay counting, a 48 h acquisition time is necessary. The same result can be obtained with AMS in about 10 min and with only 1 mg of carbon. 

Fig. 21. Schematic illustration of MP-HNCA-TROSY antiphase (a) and in-phase (b) spectra with long acquisition time in q. The corresponding subspectra are shown after addition of the antiphase and in-phase data sets (c) and after subtraction of the antiphase and in-phase data sets (d). Due to very small Vcc > the intraresidual cross peaks are almost entirely cancelled out from the antiphase spectrum (a). In the subspectra, the intraresidual cross peaks are shown as doublets, separated by 53 Hz splitting in Fi-dimension, whereas sequential cross peaks are shown as singlets, and they exhibit 53 Hz offset for the upheld and downfield components between the subspectra.

Set up the flow cytometer with fluorescence detectors turned off and the acquisition terminator set for TIME, so that a constant volume from each sample will be analyzed. A time interval (e.g., 1 min) that will be sufficient for the acquisition of approximately 10,000 events in the control samples should be used. Acquire light scatter signals (ESC and SSC) for each sample, vortexing the cell suspensions briefly but vigorously before introducing each sample into the flow cytometer. 

Fig. 6 Binding epitopes for the B-antigen trisaccharide in the presence of RHDV VLPs recorded with a Arfl = 20 xs and b Arfl = 100 s. A setting of Adi = 20 jis for the interpulse relaxation delay corresponds to a total relaxation delay t = 4.7 s since relaxation also occurs during the acquisition time. With Adi = 100 s an increase of STD effects for H2, HI, H4 and H6 " is observed. This is dne to rednced satimation dnring the off-resonance experiment resulting from a sufficient long relaxation delay...

FIGURE 6.19 Vibrational spectra of vanillin in isopropanol solntion. Bottom panel experimentally measnred CARS spectrum (1064 nm and continuum excitation, 1064 nm probe). Middle panel retrieved Raman spectrum. Top panel experimentally measured spontaneous Raman spectrum (excitation wavelength 532 nm). The acquisition time for CARS spectrum was 100 times shorter than for spontaneous Raman. The incident powers were set at approximately the same level. 

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