A Controlling And Data Acquisition System For The Reference Diffuse Reflectance Spectrophotometer Based On The IBM-PC/XT Computer

Abstract

A System has been designed for controlling, acquiring and storing the photoelectric signals for the reference reflectance spectrophotometer in the division of radiometric physics at the NBS. Based on the IBM-PC/XT computer system, the GPIB interface is chosen to connect with various instruments (such as, current amplifier, lock-in amplifier, digital voltmeter and programmable high voltage power supply etc.) The control and analysis program is written in the TBASIC programming language. This system can also be used to control several stepping motors, as well as to control the opening and closing of the shutters. This computer program can be used for both the visible spectrum region from 200 to 750 NM and the near infrared region from 750 to 2500 NM. In this paper, the reference reflectance spectrophotometer, the computer program, and the resutts of the performance test are described.