Thermometer, microscopic

Fig. 12.1 Melting point apparatus (a) oil bath (b) heated block - thermometer readout ic) heated block - digital readout (d) Kofler hot-stage microscope.

Several micro methods have been developed for the determination of the melting point, using one or two crystals of the substance. In most of these methods the crystals are placed on a slide and covered with a cover glass. The slide is then placed on a metal plate which is heated electrically by resistance wires. The temperature is measured by a thermometer or thermocouple placed close to the sample. The change in the crystals is observed through a magnifying lense or a microscope. 

Cheap and capable digital web-cameras and microscopes. These make possible surveillance of experiments and their display on computer monitors. Simple and intuitive analogue instruments, such as bulb thermometers and bourdon-tube pressure gauges, may also be monitored web cameras. 

FIG. 3 Setup for the measurements of the swelling ratio (a) image analyzer (b) CCD camera (c) microscope (d) thermometer (e) measuring cell (f) pH meter (g) conductivity meter (h) aqueous phase supply system (APSS) (i) temperature control system (TCS). (From Ref. 27.)... 

The measurements chemists make are often used in calculations to obtain other related quantities. Different instraments enable us to measure a substance s properties The meter stick measures length or scale the buret, the pipet, the graduated cylinder, and the volumetric flask measure volume (Figure 1.8) the balance measures mass the thermometer measures temperature. These instruments provide measurements of macroscopic properties, which can be determined directly. Microscopic properties, on the atomic or molecular scale, must be determined by an indirect method, as we will see in the next chapter. 

The introduction and development of Micro-Thermal Analysis are described and discussed by Duncan Price in Chapter 3. The atomic force microscope (AFM) forms the basis of both scanning thermal microscopy (SThM) and instruments for performing localised thermal analysis. The principles and operation of these techniques, which exploit the abilities of a thermal probe to act both as a very small heater and as a thermometer, in the surface characterisation of materials are described in detail. The... 

Can you imagine a thermometer that has a diameter equal to one one-hundredth of a human hair Such a device has actually been produced by scientists Yihica Gao and Yoshio Bando of the National Institute for Materials Science in Tsukuba, Japan. The thermometer they constructed is so tiny that it must be read using a powerful electron microscope. 

The stage is transferred to the intravital microscope. The heating element is connected to the roller pump and the water bath and the pump turned on. The thermocoupler is plugged into the digital thermometer (Fig. 5B). 

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