If scope of measurement does not include soluble gases the cold/dry method can be a good option.
Optimum choice of measurement method and selection of the most suitable instruments is always an individual matter and Pentol specialists do it after thorough evaluation of all conditions.
Most of gases can be measured by infrared (IR) and ultraviolet (UV) spectroscopy, both in in situ and extractive options. Each instrument of this type contains a radiation source and a detector measuring radiation intensity after passing the measurement zone. In most cases a non-dispersive measurement technique is used employing phenomenon of infrared or ultraviolet absorption of each measured gas by specific for each individual gas wavelength of radiation. Such method is called using abbreviations NDIR or NDUV respectively.
NDIR method is more universal because most of gases can be measured this way using single instrument. Ultraviolet waveband (NDUV method) cannot be used to measure CO, CO2 or H2O, however some gases can be measured more precisely. In practice it means that NDUV instruments are used for process purposes, rather than for complete CEMS.
There are, however, some other technical solutions based on infrared spectroscopy: analysers using Tuneable Diode Laser Absorption Spectroscopy (TDLAS) and Fourier-transform infrared spectroscopy (FTIR).
Flame ionisation detection (FID) is a method of measurement of total organic carbon (TOC). Sample is burnt in hydrogen flame and value of ionisation current is proportional to content of all components containing organic carbon. TOC measurement is commonly used as a part of CEMS in waste incinerators and cement plants, as well as for process purposes in chemical and petrochemical industries.