TABLE OF CONTENTS Process Analyzers are a unique category of process instrumentation and require unique handling in their selection, design, and maintenance. Most of the other (not pneumatic) process monitoring instruments are monitoring a physical property (typically pressure, temperature, flow, etc.) of the process. They are electrophysical devices and consequently require electronic and physics understanding to implement and maintain properly. Process Analyzers are utilized to monitor a chemical property (typically composition related) with an electro physical (or sometimes chemical) device in the process. Consequently Process Analyzers also require an understanding of chemistry of the process and instruments measurement techniques. This chapter focuses on the issues that are somewhat unique, special, or different for process analyzers.
A field analytical instrument system can consists of the following elements:
Sample Probe (a valved tube that inserts into the process through a packing gland or welded seal)
Sample Transfer Line (tube or pipe often insulated and/or temperature controlled between the sample probe and sample conditioning system)
Sample Conditioning System (A small process to convert the sample conditions to something that is acceptable to the analyzer. It often includes items like filters, demisters, heaters, coolers, temperature indication, flow splitters (by pass and analytical flows), pumps, aspirators, flow indicators, flow controllers, pressure indicators, and/or pressure controllers.)
Field Analytical Instrument (see next section)
Sample Return Line (tube or pipe to transfer the sample from the sampling system to a sample return point.)
Sample Return (process, flare, tank, etc.)
Calibration System (Known material used to calibrate...
