Computer-assisted measuring system

Figure 17. Schematic diagram of the computer assisted measuring system used to control the integrated scan -ningpyroelectric microcalorimeter.

While digital integrators serve to measure peak areas and retention times, they are of limited use for instrument control purposes and advanced data processing. Therefore, interest in computer-assisted chromatography systems has risen rapidly. The personal computer has to fulfill the following tasks ... 

This paper describes work on equipment and instrumentation aimed at a computer-assisted lab-scale resin prep, facility. The approach has been to focus on hardware modules which could be developed and used incrementally on route to system integration. Thus, a primary split of process parameters was made into heat transfer and temperature control, and mass transfer and agitation. In the first of these the paper reports work on a range of temperature measurement, indicators and control units. On the mass transfer side most attention has been on liquid delivery systems with a little work on stirrer drives. Following a general analysis of different pump types the paper describes a programmable micro-computer multi-pump unit and gives results of its use. 

The electrochemical cell for the polarographic measurements had a four-electrode configuration equipped with a microsyringe, and was connected to a computer-assisted data-acquisition system [7]. On the other hand, the cyclic voltammetric measurements that are also assisted by a computer data-acquisition system were carried out using a gel electrode that contains the aqueous phase [8]. The cell structure was as follows ... 

Control Devices. Control devices have advanced from manual control to sophisticated computer-assisted operation. Radiation pyrometers in conjunction with thermocouples monitor furnace temperatures at several locations (see Temperature measurement). Batch filling is usually automatically controlled. Combustion air and fuel are metered and controlled for optimum efficiency. For regeneration-type units, furnace reversal also operates on a timed program. Data acquisition and digital display of operating parameters are part of a supervisory control system. The grouping of display information at the control center is typical of modem furnaces. 

A computer-assisted system for predicting retention of aromatic compounds has been investigated in reversed-phase liquid chromatography. The basic retention descriptions have been derived from the studies on quantitative structure-retention relationships. The system was constructed on a 16-bit microcomputer and then evaluated by comparing the retention data between measured and predicted values. The excellent agreement between both values were observed on an octadecyl-silioa stationsu y phase with acetonitrile and methanol aqueous mobile phase systems. This system has been modified to give us the information for optimal separation conditions in reversed-phase separation mode. The approach could also work well for any other reveraed— phase stationsury phases such as octyl, phenyl and ethyl silicas. 

In this study two different flow-injection immunoassays are presented as well as the flexible automation system CAFCA (Computer Assisted Flow Control Analysis), which has been used for their control, uptake measurement, evaluation and visualization. Both immunoassays (a heterogeneous and a homogeneous assay) are based on the principles of flow-injection analysis and were developed for reliable, fast monitoring of relevant proteins in animal cell cultivation processes. Off-line applications of measurements of medium samples as well as online application during a mammalian cell cultivation are presented. All results are compared to results obtained with ELISA (Enzyme Linked Immunosorbend Assay). The requirements of the automation of flow-injection immunoassays with respect to their flexible control are discussed. 

Color labs are outfitted with laboratory size equipment that simulates the larger machines used for production internally and by their customers. Typical processing equipment found in the lab are small extruders, two-roll mills, ban-burry mills, and media mills. Small rotational, injection and blow molding machines are used to duplicate the customers process. Instruments and computers are required for testing physical properties and color. Most labs have a computer-controlled color measuring system and a light booth to evaluate color. The spectrophotometer with computer is initially used to assist in colorant formulation and later as a quality control (QC) tool to provide certification of the quahty of match to standard. The light booth provides a standardized set of conditions to visually observe color and appearance. 

Computer-assisted Simplex optimisation of a graphite furnace was accomplished to measure Ni using an on-line preconcentration system. 

Since the early days of computer-assisted structure elucidation, the following three processes, in general, have been adopted (1) derivation of substructures from measured spectral data of an unknown (2) generation of all possible total structures based on the derived substructures (3) examination of candidate structures thus obtained (see Structure Determination by Computer-based Spectrum Interpretation). Any automated structure elucidation system for organic compounds... 

---