Offset voltage

Cold-junction compensation can be provided by a network which includes a constant voltage source and a temperature-sensitive bridge to provide an offset voltage which is proportional to the temperature sensitivity of the thermocouple and of opposite sign. 

Modern hot-wire anemometers are normally used in the constant temperature (CT) mode, where the wire resistance and w ire temperature are kept virtually constant. In the CT-mode the wire is one part of a Wheatstone bridge circuit, which has a feedback from the bridge offset voltage to the top of the bridge (see Fig. 12.18). 

KMP100-NT-AJG-XXX Pressure range Sensitivity Temperature coefficient of output spen (TC ) Temperelure coefficient of offset voltage fTCO) 4 -0.19 -0.05 10 000 5 -017 6 -0.15 +0 05 kPa pV/VkPa %/K %/K... 

Five calibrated resistors (1% accuracy) with values of 1 kQ, 10 kQ, 100 kQ, 1MQ, and 10 MQ were connected to the input of the logarithmic converter (i.e., the input, to which the metal-oxide-covered electrodes are connected), and the output voltage (A Veb) of the logarithmic converter was measured. The common-mode voltage was 1V, the reference current was 0.1 pA, and the ambient temperature was kept at 25 °C. The offset voltage between the emitter-base voltages was less than 2 mV. The resistance values were estimated from the measurements at 2% resolution. 

The analyser applies a tiny voltage V across the sample (perhaps superimposed on a pre-set or offset voltage). The magnitude ofW varies with time since it is sinusoidedly modulated. The analyser measures the respective time-dependent currents I, and hence calculates Z and the time lag 9 experienced between the current and voltage. 

This circuit uses a LF411 op-amp macro model. All op-amp models, except the ideal op-amp model, include bias currents, offset voltages, slew rate limitations, and frequency limitations. Also note that the op-amp model requires DC supplies. The... 

The output voltage swing is limited to 15 V and we have added a pole at 30 rad/sec. This is approximately the frequency response of a 741 op-amp. Note that this circuit is still ideal because it does not include many of the other nonideal characteristics of a 741 op-amp such as bias currents, offset voltages, and slew rate. 

The RF excitation waveform is w/z-selective, which implies that a product ion is not excited and will not further fragment in the ion trap, while the collision offset voltage is equally apphed to the product ions in a triple quadrapole. This may lead to product ions from secondary fragmentation reactions. 

Figure 3.9 Fragmentation patterns in positive-ion mode of PCs. ESI-MS conditions spray voltage 4.5 kV sheath gas nitrogen 0.9L/min capillary voltage 35 V capillary temperature 200 °C tube lens offset voltage 15 V. (Reprinted from Pad et al., 2006. Simultaneous separation and identification of oligomeric procyani-dins and anthochyanidins-derived pigments in raw red wine by HPLC-UV-ESI-MSn, Journal of Mass Spectrometry 41, p. 869, with permission from John Wiley Sons Ltd)...

Table 3.14 Anthocyanins and their derivatives identified in a Primitivo wine by LC/ESI-MS analysis performing program D in Table 3.12. The characteristic fragment ions from the MS/MS and MS3 experiments of the most intense m/z signals of mass spectra, are reported. MS conditions positive ion mode spray voltage 4.5 kV sheath gas N2 0.9 L/min capillary voltage 35 V capillary temperature 200°C tube lens offset voltage, 15 V (Pati et al., 2006).

The MS conditions positive-ion mode spray voltage 4.5 kV sheath gas N2 0.9L/min capillary voltage 35 V capillary temperature 200°C tube lens offset voltage, 15V (Pati et al.,2006). 

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