Temperature coefficient of sensitivity

Functional parameters FP of a sensor include the sensitivity S, cross sensitivities, temperature coefficient TC, temperature coefficient of sensitivity TCS, offset O, and corresponding TCO. Nonhnearities of TCS and TCO are NLTCS and NLTCO. And we also have hysteresis, burst pressure, hermeticity, and other parameters. These functional parameters need to be described by model parameters MPj, j= l...n, which are appropriate for the processes used to fabricate the device (layer thickness, etching profiles, residual layer stress, etc.). 

Both the sensitivity and the offset of the bridge are functions of temperature (Fig. 6.2.2). The temperature coefficient of sensitivity (TCS) is always negative and relatively constant (typically -0.2%/K). The bridge offset creates the largest part of the temperature coefficient of the bridge offset (TCO) and is caused by the TCS compensation technique used. 

Fig. 6.2.3 Characteristics of a Wheatstone bridge after calibration of temperature coefficient of sensitivity...

Consequently not only sensor sensitivity and offset but also the linear temperature coefficients of sensitivity and offset can be trimmed. The trimming values are gain (13 bit), TCG (11 bit), offset (13 bit), and TCO (11 bit). 

Temperature Coefficient of Sensitivity Accuracy at 75°C 0.2% of Reading plus... 

The development of active ceramic-polymer composites was undertaken for underwater hydrophones having hydrostatic piezoelectric coefficients larger than those of the commonly used lead zirconate titanate (PZT) ceramics (60—70). It has been demonstrated that certain composite hydrophone materials are two to three orders of magnitude more sensitive than PZT ceramics while satisfying such other requirements as pressure dependency of sensitivity. The idea of composite ferroelectrics has been extended to other appHcations such as ultrasonic transducers for acoustic imaging, thermistors having both negative and positive temperature coefficients of resistance, and active sound absorbers. 

Notice, that with these extremely good resolutions in case of surface sensing contamination of the sensitive layer with solid particles has to be avoided completely, e.g. by an appropriate filtering of the sample solutions. Notice also that the temperature coefficient of the refractive index of water is about 10-4 per °C. So if applying the surface sensing mode using watery solutions indeed a perfect balance of both branches and low temperature gradients have to be aimed at. 

KMP010-NT-A7G-XXX Pressure rango Sensitivity Temperature coefficient of output span (TCS) Temperature coefficient of olfeel voltage (TCO) 12 -0.19 -0.05 1.000 20 -0.17 26 -Q.14 +0.05 kPa MV/VkPa W %VK... 

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... 

PATR 2667 R.C. Ling et al, "Temperature Coefficient of Mechanical Sensitivity of Primary Explosives" (Feb I960) (Conf)... 

Thermistors, or thermally sensitive resistors," are semiconductors which have high negative temperature coefficients of resistance. There is no simple re-... 

The relative contribution of these two processes is controlled by the average pore size. It is therefore possible to optimize the temperature sensitivity by the judicious choice of the porosity of the diffusion barrier layer (Vacek et al., 1986). The temperature coefficient of the sensor with 0.1-0.2 pm average pore diameter is 0.04%/°C between 640°C and 800°C. 

There are numerous uses for resistors with high values of the temperature coefficient of resistance (TCR) and they may be negative (NTC) or positive (PTC). An obvious application is in temperature indicators that use negligible power to monitor resistance changes. Compensation for the variation of the properties of other components with temperature may sometimes be possible in this case the applied power may be appreciable and the resulting effect on the temperature-sensitive resistor (TSR) must be taken into account. 

In the vicinity of 90° K the temperature coefficient of the amount adsorbed can be estimated from the published isotherms (8). This coefficient is, of course, dependent upon the pressure and the apparatus dimensions. In the pressure range where the delay occurred, and on the basis of the dimensions of the apparatus, the temperature coefficient of the amount adsorbed was calculated to be about 2% per °K. The temperature coefficient of residual pressure was of the order of 20% per °K. The greater temperature sensitivity of the residual pressure suggests that this measurement might account for the delay, but the observed pressure changes associated with delay are relatively very large. 

The volume of a drop formed by coalescence of two small drops is not exactly the sum of their volumes. The enthalpy, H, is not the sum of the enthalpies of the two small drops. In other words, a sufficiently sensitive measurement would reveal a AV and a AH associated with the coalescence. We can calculate the AH for the process with considerable precision if the drops are very small but large enough to ensure that surface tension is nearly the same as for the liquid in bulk. The calculation involves AH per unit area calculated from the temperature coefficient of surface tension (8) and the area which disappears in the process. (The coalescence of two drops of water at 25° C. each 0.01 cm. in diameter produces a temperature rise of 3.5° X 10 4° C.)... 

Quartz Crystal Thermometer. The temperature coefficient of the resonant frequency of quartz (14-20 MHz), using the piezoelectric effect, is a function of temperature (1 kHz per degree). In the temperature range -80°C to 230°C, an electronically controlled quartz crystal thermometer can be accurate to 0.02°C and has a sensitivity of 10 microdegrees centigrade in temperature difference measurements. 

A review of the physical significance of the dimensionless parameters is appropriate at this point. S is the maximum possible adiabatic temperature rise, scaled by the temperature coefficient of reaction rate. It is a measure of the sensitivity of the reaction to changes in operating conditions, and is sometimes designated by "B" in the literature. "D" is the residence time multiplied by the specific rate constant at the inlet, often called the "number of reaction units", x is the temperature rise, scaled by the temperature coefficient of reaction rate. The maximum possible value of x is S. 

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