Improved automated electronic balance calibration program

摘要

An improved automated electronic balance calibration and record system has been developed using a spread sheet to consolidate information required to calibrate electronic balances and satisfy requirements for traceability, validation and documentation. Several improvements have been made over an Epson HX-20(trademark) notebook computer-based balance calibration system, which was developed at the Savannah River Site in 1986 and used continuously since to annually calibrate electronic balances. These improvements included: built in tables of balance models performance test limits and calibration standards' apparent masses & uncertainties; calculated ratios of balance to test weight uncertainties; bar-code data input; enhanced graphs and tables; and permanent electronic records. The software and hardware were thoroughly tested by calibrating 30 balances in another department. Hardware for importing data from balances through an RS-232 interface and bar code reader into a portable computer's spread sheet was evaluated and found to add little value to the calibration process. Computerized data collection minimizes record handling and reduces paper work costs by >50%. Databases are established for each organization's electronic balances that contain records for each balance that are identified by model, property identification number and location. In addition, each record contains calibration and expiration dates, performance testing information, etc. Details of equipment, statistical testing, spread sheet features and examples of the program are described.