A Small Laboratory Automation System Composed of Microcomputer-Based Spectrophotometers

Abstract

A distributed microcomputer network system which consists of integral microprocessors in intelligent instruments has been developed for automating the spectroscopy laboratory. In this system, the master-slave arrangement of microcomputers is adopted to compose the system controller and three microcomputer-based spectrophotometers (an UV/visible spectrophotometer, an IR spectrophotometer, and a fluorescence spectrophotometer). The IEEE-488 standard interface bus is employed for the hardware compatibility of the communication between the system controller and spectrophotometer subsystems. The Tiny BASIC language is modified as a standard language in the system for real time execution along the communication through the IEEE-488 interface bus. The operation includes two modes: the local mode and the remote mode. In the local mode, the spectrophotometer is manually controlled independently from the system controller. In the remote mode, the modified Tiny BASIC program controls individual spectrophotometers. The program is written by the user at the system controller and is loaded down to the microcomputer of a spectrophotometer subsystem. This program is executed via the individual modified Tiny BASIC interpreter implemented in the subsystem. The system structure, design of the modified Tiny BASIC, and operating procedures are presented together with typical performance data.

Ultraviolet and light absorption spectrometry

“…The characteristics and applications of two general software packages for instrument control, data acquisition, and data manipulation have been reported (170,356), along with an interface to an Apple II microcomputer for continuous digital recording and storage of spectra obtained by photon counting techniques (546). A distributed microcomputer network system has been developed for central control of automated spectroscopy equipment in a large laboratory (476,477) and a Hewlett-Packard 9825 desktop computer has been used to acquire and analyze data for 50-80 determinations from an HP 8450 UV-vis spectrophotometer (239). Algorithms have been developed for determining several components in a mixture when their absorption bands are overlapped by background absorption (20,153).…”