A Word In The Hand Makes The Measurement Firm

68 A arch WORD IN THE HAND MAKES THE MEASUREMENT FIRM By David Simpson, National Physical Laboratory, Teddington, London Though electronic sensors are now widely used for laboratory measurements, many instruments, especially the more accurate ones, still have to be read by someone. A hand-held computer terminal developed at the National Physical Laboratory helps observers to record readings from instruments faster and more reliably. When numbers are keyed into it, a speech synthesizer dictates them back to confirm that data have been entered as intended. It also warns against improbable readings. Each year the National Physical Laboratory calibrates several thousand scientific instruments for customers who use them industrially to measure a wide range of parameters. Although there is a growing tendency to incorporate ana- logue or digital electrical outputs that enable readings to be recorded automati- cally by a computer, few of the instru- ments have such a facility. Vernier-sca...