Internet-Enabled Calibration: A Future of Calibration?

Introduction

Today, calibration and testing of measuring instruments is important part of metrology activities. All the laboratory instruments require recalibration in regular time intervals. Traditionally, instruments are transported from the customer to the calibration laboratory which implies a downtime for every particular instrument under calibration. There is also a danger that instruments will be damaged during transportation. The development of automated measurement procedures, evolution of the computer networks and growing number of quality standards in the industrial and research fields in recent years has led to the realization of Internet-enabled calibration systems, specifically for industrial applications. Also, Internet-enabled metrology is a wider concept that covers the use of communication systems to provide convenient access to a range of measurement and calibration services. On the other hand, calibration, including any kind of remote calibration process must adhere to the recommendations specified in standard ISO/IEC 17025 (International Organization for Standardization, 2008).

According to Dudley (2005) these services usually include some of the following:

• •

  Remote control and monitoring of measuring equipment (instruments and standards),

• •

  Traceable measurements that are performed at a customer location but controlled remotely by the calibration facility (this covers the term Internet-enabled calibration and/or testing),

  • •Access to measurement and calibration history and other related data of each instrument and standard,

• •

  Access to libraries of testing and metrology software or algorithms.

Remote calibration can be the best choice for the calibration of low-cost instruments as their calibration is quite expensive when compared with the instrument cost. The Internet-enabled calibration system must include some kind of travelling standard (or transfer standard) that must be transported from the calibration laboratory to the customer laboratory. This transfer standard, as important part of any Internet-enabled calibration have to be robust and error prone, and yet simple for operation by the customer laboratory staff. The remote testing and calibration of measuring instruments is still not fully exploited, mainly due to the security issues, which are associated with the operations outside of a calibration laboratory, primarily since the installation of the equipment including transfer standard should be done by the customer staff, and not by the calibration laboratory personnel who will sign the calibration certificate. This implies that the reliable remote control and monitoring of instruments is a crucial aspect of Internet-enabled calibration procedure. This paper presents overview of existing Internet calibration technologies, and addresses the issues that needs to be solved in the future, especially in order that Internet-enabled calibrations are in accordance with the ISO/IEC 17025 standard. Also, the realization of Internet-enabled calibration system in Primary electromagnetic laboratory of Croatia is described briefly.