Level indication using temperature

Answer An electronic temperature monitor could be equipped with a bar-code liquid crystal display which could be read by a portable bar-code reader. These devices have a memory so several readings may be taken before they are readout over a telephone modem to a data logging computer. The simplest way to read the acid type would be to post a label that is bar-coded to indicate the acid type. Tire acid quantity could be indicated by an acid level gage using a bar-code display of the level. The aluminum quality could be indicated by displaying a label in bar-code. The amount of aluminum could be determined by weight using a bar-code readout on the scales. 

Temperature-sensing devices may also be used to measure flow in pipes or ducts and for level indication of... 

On some group and district heating schemes, outlet-limiting valves which permit flow only when the water temperature has dropped to a specified low level are used. This procedure minimizes the water quantity to be pumped and permits indicative heat metering by water quantity alone. In such cases, care must be taken to size emitters to suit the available water temperatures. The effect of low water velocities through the emitter must also be taken into consideration, since the heat output of some convective appliances is greatly reduced under such conditions. 

This test on rigid plastics indicates their ability to withstand continuous short-term compression without yielding and loosening when fastened as in insulators or other assemblies by bolts, rivets, etc. It does not indicate the creep resistance of a particular plastic for long periods of time. It is also a measure of rigidity at service temperatures and can be used as identification for procurement. Data should indicate stress level and the temperature of the test. 

Equations I and J indicate that for the temperature range of interest (640 to 830 °K), the heat capacity per unit mass is substantially independent of the conversion level. Furthermore, the temperature dependent contribution to the heat capacity will not vary much over the temperature range involved. Hence without introducing errors comparable to those inherent in the use of a one-dimensional model, we may take the heat capacity as constant at 0.250 cal/g-°K or 0.250 BTU/(lb-°F). 

Dissolution indicates the rate-limiting step for compound absorption when drugs are administered orally. The solubility of a pharmaceutical compound represents its maximum concentration in an aqueous buffer. Additional compound will not dissolve above this concentration. The solubility value is often heavily dependent upon pH and temperature and is typically measured at physiologically important pH levels and body temperature. The standards for dissolution testing are determined by the United States Pharmacopoeia (USP). Testing typically requires sampling of a solution at 15, 30, 45, and 60 min for immediate-release products. /./Pl.C is ideally suited for use in conjunction with USP apparatus types I or II and can rapidly analyze multiple time points or replicate samples. 

Tanks with vent hlters must be designed for pressures of -20 kPa and +100 kPa and must be equipped with a rupture disk. Tanks for hot loop and steam sterilizable line must be designed to withstand steam sterilization (121°C). A steam jacketed sterile vent hlter must be used to avoid condensation in the hlter and the vent hlter housing temperature controlled. The tank for hot storage is steam jacketed and insulated for temperature maintenance. Minimum instrumentation shall include level indication, temperature recording controller, pressure gauge, and pressure relief valve. 

Although ultrasonic level indicators require little maintenance and are unaffected by the nature of the liquid (acidity/basicity, dielectric constant, or specific gravity), they cannot be used in circumstances of excessive foaming or turbulence or in high-temperature situations where stratified vapor layers may be present. 

The determination of the photoluminescence parameters (excitation frequency, emission frequency, Stokes shift, fine structure parameter, and lifetime) can lead to information which, at the simplest level, indicates the presence of an electronically excited state of a species, but which can be sufficiently detailed so as to lead to a clear identification and characterization of the photoluminescent sites(J6-44). Moreover, measurements of the variations in the intensity and positions of the bands as a function of time (time-resolved photoluminescence) provide valuable kinetic data representing the reactions occurring at the surface. Although most of the photoluminescence measurements have been carried out at low temperatures for specific reasons (see Section III.C.2), there is much evidence that some of the excited states involved are present even at higher temperatures and that they play an important role in catalytic and photocatalytic reactions. Therefore, it is clear that the information obtained by photoluminescence techniques is useful and important lor the design of new catalysts and photocatalysts. 

Different feedstocks and/or solvents require different solvent to feed ratios. Each packing has a specific flooding point These two effects can lead to a great difference in mass flow. Because of this, pressures and temperatures should be controlled automatically. The flow must be measured exactly, preferably with a mass flow meter, but automatic flow control is not suitable for a multi-purpose plant The valves which are used for pressure and temperature control should be installed so that they can be replaced easily or adapted to new conditions. A very important requirement for the continuous operation of the plant is liquid level indication and control in the extractor and regenerator. Therefore the plant is equipped with capacitive level sensors which are part of a control circuit. The suitability of these sensors for measuring the level of oily products, vitamins and some type of hydrocarbons in supercritical systems have been tested in the lab previously. 

---