The Q46H/79S total chlorine monitor from Analytical Technology uses standard iodometric chemistry, but with a sensing technique for measuring the released iodine. The system takes the reacted sample containing iodine and uses an air-stripping system to remove molecular iodine from the solution. The gas-phase iodine from the water sample is channeled through a conditioning module and then directly to an iodine gas sensor. The result is that the iodine measurement is made without any contact between the water sample and the sensor. Contaminants in the sample that cause fouling and contamination of standard electrodes do not affect the system. 800/959-0299; www.analyticaltechnology.com.