Bath, thermostatic

Finally, other tests to control jet fuel corrosivity towards certain metals (copper and silver) are used in aviation. The corrosion test known as the copper strip (NF M 07-015) is conducted by immersion in a thermostatic bath at 100°C, under 7 bar pressure for two hours. The coloration should not exceed level 1 (light yellow) on a scale of reference. There is also the silver strip corrosion test (IP 227) required by British specifications (e.g., Rolls Royce) in conjunction with the use of special materials. The value obtained should be less than 1 after immersion at 50°C for four hours. 

Batch Reactors In the simplest land of investigation, reactants can be loaded into a number of ampules, kept in a thermostatic bath for various periods, and analyzed. 

The effect of temperature has already been referred to the electrolysis cell should be immersed in a thermostat bath maintained within 0.2 °C for many purposes a temperature variation of 0.5 °C is permissible. A temperature of 25 °C is usually employed. 

It is seen that in order to measure retention volumes with a precision of 0.1%, the temperature control must be +/- 0.04°C. This level of temperature control on a thermostat bath is not difficult to achieve but it is extremely difficult, if not impossible, to return to a specific temperature to within +/- 0.04°C after prior change. To achieve a precision of retention volume measurement of 1%, the temperature control must be +/- 0.4°C. This is far more practical as most column oven temperature can be set to a given temperature to within +/-0.25°C. Although the data was obtained for three specific solutes, the results can be taken as reasonably representative for all solutes and phase systems. In most practical analyses, the precision limits of retention volume measurement will be about 1% but this will not include the reproducibility of the flow rate given by the pump. As... 

A special glass device called a kinematic viscometer tube is shown in Fig. 3.6. To use the device, the liquid is added to the tube to fill the large bulb on the right. The tube is submerged in a thermostatted bath so... 

Figure 7.7 Scheme of an isoperibol macro rotating-bomb combustion calorimeter. A calorimeter proper B bomb C thermostatic bath D motors for rotation of the bomb E drive shaft F stirrer of the calorimeter proper G motor that drives the stirrer F H motor that drives the stirrer of the thermostatic bath I miter gear J gas outlet valve K gas inlet valve L crucible. 

Figure 11.2 shows a typical temperature-time curve for a continuous isoperibol titration calorimetry experiment involving an exothermic process. In the initial and final periods (between points a and b, and c and d, respectively), the observed temperature change is determined by the heat of stirring, the heat dissipated by the temperature sensor, and the difference between the temperature of the calorimetric vessel and the temperature of the thermostatic bath. The titration... 

The temperature coefficient of conductance is approximately 1-2 % per °C in aqueous 2> as well as nonaqueous solutions 27). This is due mainly to thetemper-ature coefficient of change in the solvent viscosity. Therefore temperature variations must be held well within 0.005 °C for precise data. In addition, the absolute temperature of the bath should be known to better than 0.01 °C by measurement with an accurate thermometer such as a calibrated platinum resistance thermometer. The thermostat bath medium should consist of a low dielectric constant material such as light paraffin oil. It has been shown 4) that errors of up to 0.5 % can be caused by use of water as a bath medium, probably because of capacitative leakage of current. 

A so-called Rosett cell can be fitted with a flanged lid (Fig. 7.12). The design of the Rosett cell allows the irradiated reaction mixture to be sonically propelled from the end of the probe around the loops of the vessel and thus provides both cooling (when the vessel is immersed in a thermostatted bath) and efficient mixing. A PTFE sleeve provides a vapour tight fit between the probe and the glass joint. 

Heating system, usually consisting of thermostatted baths or electrical wires wrapping the coils to favour the development of the analytical reaction. 

Fig. 3.11. Schematic drawing of assembly for dosing water into phials by volume of vapour. A reservoir containing distilled, deaerated water, B dosing bulb of known volume, P breakable phials, C container holding MejSiCl, D thermostat bath.

The whole apparatus is baked as efficiently as possible without evaporating large quantities of the manometric fluid or test substance, and is finally sealed off. The apparatus is returned to the vertical position and wholly immersed in a thermostatic bath. The level of the manometer liquid should be exactly equai under these conditions. The apparatus is then arranged as shown in the sketch with bulb B in solid carbon dioxide or liquid nitrogen. When equilibrium is attained the difference of level in the manometer limbs is observed with a cathetometer. The thermostat temperature is readjusted and the process repeated. ... 

The col was filled with a bottom hole crude sample and immersed in a thermostatted bath. After one hour at 46°C, the temperature of the bath was gradually decreased at 1.5°C/hr to 4°C and maintained at this temperature for two weeks. After the test period, flow was obtained by applying 0.04 bar (equivalent to 30 psi In field with 5" flowline), indicating that cold start-up would not be a problem ir the field. 

Self-Diffusion Experiments. Diffusion was measured in a U-tube cell constructed in halves which could be clamped together with the disk or skin separating the arms of the U. Cells were secured on the arms of a shaker in a thermostat bath. Unlabeled aqueous salicylic acid solution (3... 

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