Process Monitors - What Are They?
On-line process monitors are equipment that automatically takes a sample of the process, analyzes the sample, reports the results, cleans itself, and finally resets itself to repeat the operation.
In each case, the SemiChem, AnaChem, and IonChem will automatically sample, analyze, and report chemical concentrations to a process control system. Each of the products, as well as most on-line process monitors, have a wet-chemistry module, the sample system, and the electronics with operating software.
Global Measurement Technologies’ products have advanced wet chemistry modules that ensure precise and accurate analysis of the sample. The wet chemistry module consists of an analysis cell, mixer, sensors, and digital burette. The analysis cell allows for a consistent sample size and, if required, sample dilution. Sample volume is accurate to +/-0.1% relative error. The sensors are electrochemical sensors that offer high range of analyte options, wide detection ranges, high precision, and high signal to noise ratios. Finally, the digital burettes are a simplified design that is controlled via digital signals that allows for the burette operation to be optimized with regard to analysis precision and accuracy.
The sample systems for each of the SemiChem, AnaChem, and IonChem have been designed for the expected applications. In each case, the sample system is the interface between the process analyzer and the customer’s process. The design reflects the many variations of the applications that the analyzers may be exposed to such as high temperature, high purity, suspended solids, slurries, high pressures, and corrosives. The AnaChem and IonChem gained market acceptance by offering the first true filter free sample system for the most demanding applications. The large bore, robust system allows high solid content without the need for filtration, thus eliminating the need for a filtration unit and the associated maintenance. The SemiChem is not likely to be exposed to high solids, but high purity, corrosives, and high temperature. The SemiChem’s sample system has been designed to interface with process tools, blend and distribution system, and bulk chemical systems while maintaining process purity. In the extreme, the SemiChem can be configured for Nitride Etch applications with 180 Celcius and 85% acid concentrations.
Finally, the electronics and software allow the end-user to freely interact with the process monitors. The menu-driven software allows the end-user to configure the analyzers within minutes of initial operation. All parameters are easily accessed and movement through the software is intuitive. The back-lit LCD displays all pertinent analysis information, including a real-time analysis response curve on a bright large display. The real time analysis response curve is a useful troubleshooting feature indicating the validity of the analysis results. The electronics offer a variety of inputs and outputs to allow easy integration of the SemiChem, AnaChem, and IonChem into either an analog control system or a digital control system.
Global Measurement Technologies believes that the SemiChem, AnaChem, and IonChem have technically excelled in each subsystem of on-line process technology. Global Measurement Technologies engineers these products to be seamlessly placed on-line for analysis time and time again without question.
