Abstract: A method of plotting traces of data on two or more graphs, wherein each trace is related to the output of a process sensor, includes generating a list of sensors and grouping the sensors according to a unit of measure each sensor is configured to detect. One axis of a first graph is associated with the unit of measure of a first group of sensors and one axis of a second graph is associated with the unit of measure of a second group of sensors. Each sensor of the first group is associated with a trace to be displayed on the first graph and each sensor of the second group is associated with the trace to be displayed on the second graph. The traces are displayed on the first and second graphs, with each trace being related to the output of a sensor over time.

Abstract: Titration apparatus includes two cells that receive and contain liquids and are transparent to light. A liquid having an unknown characteristic and mixed with an indicator that is optically responsive to a titrant is disposed in the cells. Light is transmitted through each cell to separate photosensors. The photosensor signals are compared and a titrant is added to one of the cells in known-volume increments until the difference between the signals reaches or exceeds a prescribed threshold. The characteristic of the liquid is calculated from the quality of known concentration titrant added in order to reach or exceed the prescribed threshold.

Abstract: A chemical process control system includes a plurality of sensors for sensing various parameters of several baths employed in a chemical process. A microprocessor is employed to interrogate each sensor, to determine bath characteristics from one or more of the parameters, and for comparing the parameters to established limits. The microprocessor initiates corrective responses whenever a characteristic falls outside its specific limits in an attempt to restore the characteristic to a specified operating target value.A hierarchy of authorization keys limits access to the apparatus depending upon the level of authority of the person seeking access. Different degrees of authority may be delegated for an apparatus operator, a supervisor and servicing personnel. The apparatus includes a local and remote communication capacity for sending messages concerning malfunctions in the apparatus and for receiving instructions from a remote location for correcting malfunctions.