Resistance drift

T. Itoh, I. Matsubara, W. Shin, N. Izu, and M. Nishibori, Anal3dical study of resistance drift phenomena on (PANI)(x>Mo03 hybrid thin films as gas sensors. Bull. Chem. Soc. Jpn., 81, 1331-1335 (2008). 

Ihokura K, Watson J (1994) The stannic oxide gas sensor—principles and applications. CRC Press, Boca Raton, FL Itoh T, Matsubara I, Shin W, Izu N, Nishibori M (2008) Analytical study of resistance drift phenomena on (PANHxMoO hybrid thin films as gas sensors. Bull Chem Soc Jpn 81(10) 1331-1335 Jamnik J, Kamp B, Merkle R, Maier J (2002) Space charge influenced oxygen incorporation in oxides in how far does it contribute to the drift of Taguchi sensors Solid State Ion 150 157-166... 

When a part of a resistor becomes too hot a resistance drift occurs. The magnitude of this drift depends on the resistive material and its geometry. The maximum allowed temperature depends also on the specified maximum drift therefore, for precision resistors a lower temperature is allowed. 

Rhodium alloys find most of their applications in electrical contacts for radio frequency circuits, precision potentiometers, and spark plug electrodes. The trend is toward lower usage in electronics, mainly because of price. Osmium has minor uses in electrical equipment, mainly in contacts. Ruthenium is used in electrical contacts and high-voltage relays up to 500°C because even RuO c is conductive. A ruthenate thick-film paste is used for printed circuit resistance elements. The ruthenate is converted to RuOa, which has very low resistance drift, 0.10%. 

Drift Due to Trimming. Laser trimming produces a very severe thermal shock in thick-film resistors and can lead to microcracking in the neighborhood of the kerf. These microcracks can cause resistance drift during storage at elevated temperatures. 

Styrene—maleic anhydride (SMA) copolymers are used where improved resistance to heat is required. Processes similar to those used for SAN copolymers are used. Because of the tendency of maleic anhydride to form alternating copolymers with styrene, composition drift is extremely severe unless the polymerization is carried out in CSTR reactors having high degrees of back-mixing. 

The energy-dispersive (EDX) solid state detector (SSD, Figs 4.6, 4.7) is made of lithium-drifted Si crystal (Si(Li)). Between a thin p-type and an n-type layer lies a high-resistivity Si crystal of centimeter dimensions. The front and end planes of the crystal are coated with Au and serve as electrodes. The crystal, cooled to 77 K by liquid nitrogen, represents a p-i-n diode (Fig. 4.7). An incident X-ray photon with... 

In an oriented porous medium, the resistance to flow differs depending on the direction. Thus, if there is a pressure gradient between two points and a particular fluid particld is followed, unless the pressure gradient is parallel to oriented flow paths, the fluid particle will not travel from the original point to the point which one would expect. Instead, the particle will drift. 

Resistance thermometers are made of a pure metal, such as platinum, nickel, or copper. The electrical resistance of such a material is almost linearly dependent on temperature. Resistance thermometers are stable, having a small drift. A widely used and the best-known resistance probe is the IW-100 probe, which is platinum, having a resistance of 100 ohms at the temperature of 0 °C. Other resistance values for PT probes are available. The resistance versus temperature values as well as tolerances for platinum probes are standardized. The shape and size of a resistance probe can vary considerably, resulting in changes in probe dynamics. 

The data indicate that elastic shock-compression resistance measurements can provide data on the effects of strain on energy gaps and deformation potentials in semiconductors. Drift mobility measurements on holes in germanium and resistivity measurements on samples with different dopings would appear to be of considerable interest. 

Drift Diameter Outside Diameter Collapse Resist- Internal Yield ... 

Compensation is made for variations in ambient air pressure and temperature, calorific value, boiler resistance due to fouling and burner performance drift by trimming the air damper with a separate servo motor. 

Valve voltmeters were widely used in the past, but have been replaced by transistor voltmeters. With instruments of this type it is possible to achieve an input resistance of 50 MQ or more, the current required to operate the instrument being of the order of 10" A. The early instruments had a tendency to zero drift on the lower ranges, but this has been overcome in the modern transistor types. Such instruments are most often used to make potential readings in extremely high-resistance electrolytes. The accuracy of such instruments is of the order of 2% full-scale deflection. It is necessary to ensure that both types are so designed that they do not respond to alternating currents. 

A matter of considerable importance in the selection of an application method is its efficiency. Spray techniques are usually inefficient, since many droplets drift past the target and are lost. Even electrostatic spraying can waste as much as 35% of the paint. There is some loss of paint in most methods, but roller coating, curtain coating and electrodeposition are very efficient. Electrodeposition is also a very useful technique where corrosion resistance is important, since it applies a uniform coating over nearly all surfaces of even the most complex-shaped article. 

Electrical resistivity, flcm 4-40 Bandgap at 300K (eV) 0.66 Drift Mobility... 

Although the broad spectrum of Quantum Chemistry represented by the thirty or so articles contained in this volume only partially reflects the variety and richness of Berthier s preoccupations, it should convey to the coming generation of quantum chemists and to all readers the useful lesson of an outstanding chemist maintaining wide interests and resisting the drift of fashion. 

---