Microprocessor-controlled model

With their Models 763 and 764 microprocessor-controlled pH meter, Knick deliver and adapted Model 790 serial printer this yields in a simple way by means of an AC-synchronous clock and two adjustment knobs a hard copy of measurements at intervals of 2, 5, 10, 30 or 60 s or minutes printed out in a 32.5-mm rule of 12 positions on a small paper roll. 

In 1976, Radiometer61 presented for the first time a microprocessor-controlled titration system. Since then, the microprocessor has been used preferentially and as a fully integrated part (in line) in electroanalytical instruments as a replacement for the on-line microcomputer used before. Bos62 gave a comprehensive description of the set-up and newer developments with microprocessors in relation to microcomputers and indicated what they can do in laboratory automation. Many manufacturers are now offering versatile microprocessor-controlled titrators such as the Mettler DL 40 and DL 40 RC MemoTitrators, the Metrohm E 636 Titroprocessor and the Radiometer MTS 800 multi-titration system. Since Mettler were the first to introduce microprocessor-controlled titrators with their Model DK 25, which could be extended to a fully automated series analysis via the ST 80/ST 801 sample transport and lift together with the CT 21/CT211 identification system, we shall pay most attention to the new Mettler MemoTitrators, followed by additional remarks on the Metrohm and Radiometer apparatus. 

Mitsubishi also supply a microprocessor-controlled automatic total halogen analyser (model TOX-IO) (Fig. 1.8 (b)) which is very similar in operating principles to the Dohrmann instruments discussed above, i.e. combustion at 800-900°C followed by coulometric estimation of hydrogen halide produced. 

Mitsubishi supply two total nitrogen analysers the model TN-10 and the model TN-05 microprocessor control chemiluminescence total nitrogen analysers (Fig. 1.8 (a)). 

Pressures within the optical cells are adjusted using a microprocessor-controlled supercritical fluid syringe pump (Isco model SFC-500). The temperature of the cylinder head is regulated using a VWR 1140 temperature bath. The output from the pump is directed through a 2 /xm fritted filter and a series of valves into the optical high pressure cell which is temperature controlled ( 0.1 °C) by a Lauda RLS-6 temperature bath. The local temperature of the optical cell is determined using a thermocouple (Cole Palmer) placed directly into the cell body. 

The first commercially available flame photometer was introduced in the 1940s by the Perkin-Elmer Corporation. In 1948, Beckmann Instruments, Inc., introduced a flame attachment that could be used with their popular model D.U. spectrophotometer. By the late 1950s, instruments had been developed that used lithium as an internal standard to maximize precision. Autodilution features and microprocessor-controlled operations became widely used options in the 1970s. The most recent significant development was the introduction of cesium as the internal standard, by Instrumentation Laboratory, Inc. (Figs. 1-3). This development makes concurrent lithium determinations more practical. 

Injection valves designed for FIA are produced by a number of manufacturers. These valves are often microprocessor controlled (26) and are quite versatile. However, for all of the analyses described later, a simple low-pressure rotary injection valve designed for liquid chromatography is adequate (e.g., Rheodyne Model 50). Pneumatic and electric actuators are available for automated operation. An injection valve that can be machined quite easily from poly(tetrafluoroethylene) (PTFE, Teflon) and Plexiglas is described elsewhere (25, 27). 

The use of modern temperature detection methods in thermal titration has increased considerably in recent years, with several commercial instruments now available. Marini and Martin have recently reviewed this field (Marini and Martin, 1979) extensively so that only a brief discussion will be given here. We have developed a combined pH—thermal differential titration apparatus that is modelled after our earlier single-cell system (Berger et al., 1974 Marini et al., 1980). Figure 14 shows the essentials of the instrument. The unique part of this device is that it is under microprocessor control. The computer starts the titration, records the data, and speeds up or slows down the titration automatically if the curve is changing too rapidly. Data-correction programs adjust for response time and... 

They modified an existing autoclave and a real-time digital microprocessor control system so that It could be operated In a semi-continuous mode. Various components of MSW were studied In order to obtain meaningful data, not confused by the different thermokinetics of different MSW components. Feedstocks Included wood flour, cardboard, newsprint and rice (starch), as well as the Important model compounds alpha cellulose and lignin. It was found that these MSW components could be converted to liquid oils and a high-heating value residual solid at temperatures of 325 0 to 400 0 and pressures of 1000 psl to 3000 psl. 

The newer models offer interface capability with most laboratory minicomputers (Mark III-S and J-20) or can be linked to a specially designed data processor (J-500 to DP-500/501). The I. S. A. Jobin Yvon model Mark IV electronics are microprocessor-controlled, and Mark V can be obtained with a minicomputer. 

Dynamic Mechanical Analysis and Stress Relaxation Behavior. Samples were compression molded into bars of the dimensions 38.xl2.5x0.78 0.007 mm and 65.x9.7xl.7 0.007 mm in a Carver laboratory hot press model C. A TA Instruments 983 DMA, which was operated in the fixed frequency mode, was used to characterize the storage and loss moduli as a function of temperature. Samples were scanned at fi-equencies from 0.05 to 10.0 Hz over a temperature range from -150 C to above the glass transition temperature. The displacement was 0.4 - 0.6 mm. Stress relaxation curves were determined for the same size samples at a constant strain. The sample was displaced for 10.0 minutes and then allowed to recover for 10.0 minutes. The stress data were taken in five degree increments. A microprocessor controlled Liquid Nitrogen Cooling Accessory (LNCA) was used for sub-ambient operations. 

Smart materials are modelled upon biological systems with sensors acting as a nervous system, actuators acting as muscles and microprocessor controllers acting as a brain. These concepts are currently being applied to advanced composite materials where sensors and actuators can be embedded during fabrication (Davidson 2002). 

A microprocessor controlled instrument, Sargent Welch Model 7001, also performs pulse techniques. A 20-character alphanumeric display and a 30-touch button keypad allow the user to specify the experiment. After recording a voltammogram, smoothing, averaging, and background subtraction are options. The price in 1980 was 8800. Pulse widths from 1 to 1000 ms may be chosen, with sampling from 100 x3 after pulse initiation to 500 ps before the end of each pulse. 

Mitsubishi also supplies a microprocessor-controlled automatic total halogen analyser (model TOX-10) which is very similar in operating principles to the Dohrmann... 

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