Development of an automated high accuracy pH measuring instrument with full audit reporting facility

Scientific laboratories should now comply with Good Laboratory Practice (GLP) and the requirement of full auditing. Current pH instrumentation can not fully provide for this due to the lack of automation. Automation will mean that the instrument will be able to maintain its calibration and work to Standard Operating Procedures without deviation. This paper shows how a design specification for an automated pH instrument has been developed to create a new market in pH measurement. It outlines the control and signal conditioning electronics which are needed for highly accurate pH measurement. The GLP audit reporting functions shows how it is now possible to produce full working history reports of the instrument. The strict design requirements needed for cost effectiveness in manufacture, build/service time and for modularity, are also dealt with