DEVELOPMENT OF AN INTERNET-BASED SYSTEM FOR CALIBRATION OF INSTRUMENTS

Abstract

In a conventional calibration service, the clients send their instruments to a laboratory for routine calibration. During the service time, the clients are not able to use their instruments due to downtime. Some of their instruments are huge and heavy such as power source transformer which is difficult to be transported. One of the solutions for these problems is to send an engineer together with a standard measurement instrument to a client site to perform the calibrations. Another way of solving the problem is to send only the measurement instrument to a client site where the instrument and the unit under test are controlled by a computer that links with the laboratory computer over the internet. The calibration engineer can monitor the calibration progress remotely from his laboratory without going to the site. This can improve the calibration service and bring satisfaction to the client. The research project conducted as described here is to develop a calibration system that allows the client instruments to be calibrated at the remote location. The existing internet facility and its advancement pave the way for development of internet calibration system. The methodology of internet calibration is based on the technology of client-server applications. It is distinguished by the connected online calibration service that it provides. Most of the instruments are equipped with communication interfaces such as RS-232 port, network interface or IEEE-488 interface. When these instruments are connected to the computer, their operations can be controlled by the computer. A software system is needed to control the calibration process. The system has to extend its III capability over the internet to gather the calibration information from the national laboratory. In other words, the national laboratory provides a server system that contains the calibration information waiting for client’s computer to connect from a remote area. Upon the connection, client’s computer is able to automate the calibration via the instruments communication interfaces. The calibration data is then sent back to the system server for process. Customers from various industries and services will benefit from this implementation. This system can reduce their instruments downtime. Their instruments performances are directly traceable to national laboratory. Experts from national laboratory can share their skills and knowledge with the customers. The internet calibration which follows through a pipeline of stages is realized in this dissertation