Peltier elements

Silicon drift detectors (SDD, Figs 4.8 and 4.9) now also provide sufficient resolution (FWHM = 0.175 keV) above a sample spot sized 2 x 2 to 100 x 100 mm, and enable high-speed operation (> 10 counts s ). SDD can be combined with microelectronics and applied in portable TXRF models for microanalytical applications [4.30]. They must be cooled by a Peltier element. 

The dewpoint hygrometer detects the dewpoint temperature of air by cooling a surface in contact with the air to the dewpoint temperature. There are several ways to achieve cooling and to observe the formation of condensate on the surface. The early dewpoint hygirometers were cooled simply by applying the vaporization of ether or some other suitable liquid. Condensate formation on the surface was determined visually. Other cooling methods are to use a refrigerant flow in direct or indirect contact with the back of the surface, or to use electricity with a (thermoelectric) Peltier element. 

Especially for temperature-dependent partition processes, besides temperature-influenced humidity of the vapor phase, a thermostat device is recommended for development. The Baron TEC thermobox 200 and Desaga TEC thermobox respectively (Figure 5.25) can be adapted to suit current development chambers using a variable covering mask. A Peltier element with integrated temperatnre control... 

The CPA [188], marketed by ThermoMetric AB (Sweden), is frequently used in Europe. It operates on the principle of power compensation, which is based on the supply or withdrawal of heat to and from the reactor, respectively, in order to keep the temperature at the set-point and, thus, to compensate for energy differences (either shortage or surplus). The heat is supplied or withdrawn by means of special (Peltier) elements, which produce a cold or a hot surface area if subjected to an electrical current. An accurate measurement of the heat supply/withdrawal is possible as the heat flow is directly proportional to the current supplied to the Peltier elements. 

Hamilton Umicon Lumicon chemi- and biolumium assay luminometer This equipment is used in test-tube scale luminescent immunoassays. With its sample compartment (thermostatted by means of Peltier elements, which allow the temperature to be set from 15°C to 40°C with a precision of 0.1°K) this instrument is suitable for the measurement of temperature-sensitive bioluminescence resulting from enzymic reactions and also in phagocyte-mediated luminescence measurements. 

The APEX system (Element Scientific Inc., Omaha) as an improved Aridus nebulizer was introduced for ICP-MS in 2004 for more effective solution introduction at flow rates from 20-400 p,lmin-1.88 In this solution introduction system (see Figure 5.15), a microflow PFA nebulizer is combined with a heated cyclonic spray chamber followed by cooling of the nebulized aerosol in a condenser loop and using a multipass condenser cooled by a Peltier element. The APEX solution introduction system results in a significant increase of sensitivity (by a factor of ten in comparison to a standard nebulizer spray chamber arrangement) and a decreasing polyatomic formation rate.89... 

The experimental arrangement of LA-ICP-MS using a powerful laser ablation system coupled to a double-focusing sector field ICP-MS (Element, Thermo Fisher Scientific, Bremen) is shown in Figure 5.22. A cooled laser ablation chamber using two Peltier elements in serial connection... 

Figure 5.22 Schematic of laser ablation inductively coupled plasma mass spectrometer a laser ablation system (wa velength 213 nm) is coupled to a double-focusing sector field ICP-MS (Element, Thermo Fisher Scientific, Bremen). The cooled laser ablation chamber using two Peltier elements was developed in the author s laboratoryJ26 (M. V. Zoriy, M. Kayser, A. Izmer, C. Pickhardt and J. S. Becker, Int. J. Mass Spectrom., 242, 297 (2005). Reproduced by permission of Elsevier.)...

The calorimeter that has been used to obtain the results presented in this section basically combines the power-compensation and heat-balance principles (see Sections 8.2.2.2 and 8.2.2.3). The heat-balance principle is implemented by Peltier elements [18]. This new... 

Figure 19 Active electrical reactor cooling using Peltier elements.

Figure 9.6 Experimental setup for measuring the angular distribution of the scattered light at different temperatures and externally applied electric fields. L is a He-Ne-laser, A/2 a half-wave retarder plate, P a Glan-Thomson prism, BS a beam splitter, PDl and PD2 are photodiodes and HV the high voltage amplifier. The sbn sample with 0.66 mol% Cerium is placed on a stack of Peltier-elements to control the temperature.

Agilent Capillary Forced-air temperature cooled with Peltier element. http //www.chem.agilent.com/cag/... 

By two dimensional (2D) imaging of brain tissues, a defined sample area (several cm ) of a thin section of brain tissue (thickness 20(j,m) was ablated hue by line with a focused laser beam in a cooled laser ablation chamber (using two Peltier elements behind the target holder made of aluminium). The spot size of the laser beams was about 50(xm, the laser power density 3 x 10 Wcm . Ion intensities of the analytes, e.g., P+, Cu or Zn , were... 

Figure 6 Chip component of the MicroChannel assay system, (a) Overview of the entire chip, (b) detail of capillary pumps, which provide autonomous filling of each channel by capillary action, (c) each capillary retention valve prevents drainage of a channel s reaction zone after the fill port has emptied, and (d) a chip with an attached PDMS cube is fdled by a standard pipette. By placing the chip on 2 aluminum blocks, whose temperature is individually controlled by 2 Peltier elements, differential evaporation allows extremely low flow rates...

Peltier elements are sometimes used to generate either high or low temperature. Temperature control is mostly achieved by thermocouples. 

Figure 13 mHP for eleetronie eomponent eooling ( using Peltier element)... 

Development of simple, low-cost calorimeters for routine analysis, called thermal enzyme probes (TEP), has been attempted by several groups. These are fabricated by attaching the enzyme directly to a thermistor [4, 5]. However, in this configuration, most of the heat evolved in the enzymic reaction is lost to the surrounding, resulting in lower sensitivity. The concept of TEP was essentially designed for batch operation, in which the enzyme is attached to a thin aluminum foil placed on the surface of the Peltier element that acts as a temperature sensor [6]. 

Miniaturized coolers can be obtained also by using the Peltier element in reverse polarity as thermal device however, in this case, the excess heat at the bottom side must be dissipated. Debowski and Vancso reported on a simple water-cooled device that allows one to operate the AFM at temperatures of <15°C [53]. 

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