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NIST Authors in Bold
|Author(s):||Thomas C. Larason; Yoshihiro Ohno;|
|Title:||Calibration and Standardization Issues of UV Sensors for Water Disinfection|
|Published:||August 01, 2005|
|Abstract:||Ultraviolet radiation (UV) effectively inactivates common pathogens found in ground and surface waters such as Cryptosporidium, Giardia and most bacterial pathogens. Water treatment facilities recently started using ultraviolet radiation for disinfection of drinking water, replacing standard chemical treatment. Typically, low-pressure and medium-pressure mercury lamps are used in the UV reactors at the facilities. In these reactors, water flows at a given flow rate to receive an appropriate UV dose. UV sensors mounted on the wall of the UV reactor or inserted into the water flow monitor the dose level by measuring the irradiance from the lamps. The UV sensors currently in use have a variety of designs and performance characteristics. Austria and Germany have developed or are developing standards for the sensor design and performance. These two standards differ in their requirements and do not address many of the problems associated with the UV monitors. Furthermore, there are already many water plants in the U.S. employing UV sensor systems consistent with one or the other standard. To resolve this confusion, American Water Works Association Research Foundation (AwwaRF) decided to develop new guidelines for UV monitors. NIST is participating in this project, with funding from AwwaRF, in collaboration with Carollo Engineers (Boise, ID), Camp Dresser and McKee (Denver, CO), and the University of Veterinary Medicine (Vienna, Austria). NIST is measuring and analyzing the characteristics of various types of UV sensors. This information will aid in the development of new guidelines which will address issues such as sensor requirements, calibration methods, uncertainty, and traceability. (CONT'D)|
|Conference:||NCSL International Conference|
|Proceedings:||Proceedings | 2005|
|Dates:||August 7-11, 2005|
|PDF version:||Click here to retrieve PDF version of paper (288KB)|