Microcomputer-controlled

Before the pH electrode is used, it should be calibrated using two (or more) buffers of known pH. Many standard buffers are commercially available, with an accuracy of 0.01 pH unit. Calibration must be performed at the same temperature at which the measurement will be made care must be taken to match the temperature of samples and standards. The exact procedure depends on the model of pH meter used. Modem pH meters, such as the one shown in Figure 5-8, are microcomputer controlled, and allow double-point calibration, slope calculation, temperature adjustment, and accuracy to 0.001 pH unit, all with few basic steps. The electrode must... 

In this list the borderline between microprocessor and microcomputer control cannot be sharply drawn. 

UV/visible 200-750 Cecil Instruments CE 594 (microcomputer controlled) Double High... 

It is pertinent to mention here that there are a plethora of commercially available spectrophotometers of vaiying design i.e., single-beam (simple), double-beam (more precise and accurate) and microcomputer controlled built-in-recorder with separate printer and obviously having a wide-price-range from Rs 3.0 Lacs to Rs 17.5 Lacs. Evidently, it is practically impossible to describe either all or even a major fraction of, the various spectrophotometers available. 

The above two modifications have been duly incorporated in a double-beam spectrophotometer. Figure 21.6, depicts the schematic diagram of the optical system involved in a Lambda-2 microcomputer-controlled UV-VIS Spectrophotometer (Perkin-Elmer). 

Double beam spectrophotometers are being manufactured by various well-known manufacturers across the world, such as SUMADZU VARIAN CECIL BECKMAN PERKIN ELMER etc., to name a few. These instruments are mostly based on microcomputer-controlled devices with built-in recorder to accomplish faster speed and greater operating stability. 

Digital noise measurements have been obtained by use of a microcomputer controlling the sampling rate of a sensitive digital voltmeter employed to measure the potential or current fluctuations. The subsequent analysis of the derived time records is described. 

The direct-current (DC) volt-ampere (V-A) characteristics were measured with a microcomputer-controlled Keithley 617 electrometer in the temperature range 10 to 60 °C. From linear part of V-A dependences the resistance ffl - U/I was determined [32], where U is the voltage on the needle electrodes and I is the current passing through the sample. 

P. Aroca, Jr., and R. Aroca, Chemical Oscillations A Microcomputer-Controlled Experiment, J. Chem. Ed. 1987,64, 1017 J. Amrehn, P. Resch, and F. W. Schneider, Oscillating Chemiluminescence with Luminol in the Continuous Flow Stirred Tank Reactor, J. Phys. Chem. 1988,92, 3318 D. Avnir, Chemically Induced Pulsations of Interfaces The Mercury Beating Heart, ... 

Figure 3.2. Flowsketch of an olefins plant and specifications of the ethylene product. AR designates a composition analyzer and controller (after Skrokov (Ed.), Mini- and Microcomputer Control in Industrial Processes, Van Nostrand I Reinhold, New York, 1980).

M.R. Skrokov (Ed.), Mini- and Microcomputer Control in Industrial Processes, Van Nostrand Reinhold, New York, 1980. 

Sublimed Films Exposed to Vapors. The six different types of phthalocyanine films that were sublimed onto the interdigital electrodes were exposed to each of a series of seven vapors. Two devices, one for reference and one for measurement, were coated by sublimation simultaneously. Metal-free, Fe, Co, Ni, Cu, and Pb phthalocyanines were applied to the interdigital electrodes in this manner. Vapors studied were ammonia, dimethyl methylphosphonate (DMMP), water, air, benzene, and sulfur dioxide. The relative change in conductivity, S, was computed from the measured voltage by the microcomputer-controlled apparatus using the following relationship ... 

The thermodynamic stability constant of silver sulfadiazine in water has been measured by Boelema et al. (20). They made use of a microcomputer-controlled titrator and measured simultaneously the pH value with a Radiometer G2040C glass electrode and the silver ion concentration with an Orion research 941600 ion-selective silver sulfide electrode. The measured stability constant and standard deviation were logK=3.62i 0.05 n = 9, temperature 25°C, ionic strength 0.1 (sodium nitrate). The calculated conditional stability constant log K at pH 7.4 was 3.57. 

A typical proximate analysis of coal by microcomputer-controlled thermogravimetry. 

A Multi-Microcomputer Controlled, Vidicon, Stopped-Flow Spectrophotometer... 

Variable Sample Time Algorithm for Microcomputer Control of a Heat Exchanger... 

Osakai et al. used a microcomputer-controlled system for the ion transfer voltammetry procedure [20]. The system used is based on a NEC PC-9801 microcomputer, which was designed by using a polarizable oil-water interface as an ion-selective electrode surface. The system was applied to the determination of acetylcholine ion by cyclic, differential pulse, and normal pulse voltammetry at the PVC-nitrobenzene gel electrode. The amperometric measurement was carried out with voltage pulses of short durations and constant amplitude. 

F]fluoro-2 -deoxyuridine, [18F]FdUrd, 334, used in tumor chemotherapy and detection of tumors in human brain and lung, is produced for routine clinical use in a microcomputer-controlled process consisting of addition of 18F2 to 3, 5 -di-0-acetyl-2 -deoxyuridine 335, hydrolysis and elimination of AcOH from the 18F-triacetate 336 and chromatographic purification of [18F]FdUrd in tandem columns of ion retardation resin and alumina (equation 143)322. (The mechanism of elimation of AcOH from the 18F-adduct 336 has not been studied.)... 

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