Novel On-line Sensor for Measuring Dissolved CO(2) Using Attenuated Total Reflectance Technology
MBAA TQ vol. 44, no. 2, 2007, pp.
93-97 |
VIEW ARTICLE F. M. Cash (1), G. P. Broski (1), and P. J. Slier (2). 1. Thermo Fisher
Scientific, Minneapolis, MN. 2. Thermo Fisher Scientific, Jacksonville, FL.
Abstract
Traditional methods for measuring carbon dioxide, both in the laboratory and
on-line, are based on Henry�s law and use pressure and temperature to calculate
dissolved CO(2) concentration. These methods are not specific to carbon dioxide
and measure all gases, including oxygen and nitrogen. A novel sensor has been
developed that measures only dissolved CO(2) and is suitable for on-line
applications. Based on infrared spectroscopy, the sensor uses the attenuated
total reflectance (ATR) sampling technique to continuously analyze a beverage in
flow and no-flow applications. The sensor is compact and designed to fit
directly into the process. The operation and design of the sensor are discussed.
The performance of the ATR-based sensor is compared with traditional
temperature-pressure�based devices. The ATR-based sensor provides improved
measurement accuracy that is not dependent on beer type, density, or alcohol
content; is not affected by pressure surges; and can operate during CIP cycles.
Keywords: ATR technology, carbon dioxide, mid-IR, on-line measurement of
dissolved CO(2)
S�ntesis
Los m�todos tradicionales para medir el contenido de gas carb�nico, tanto en
el laboratorio como en l�nea, se basan sobre la ley de Henry y utilizan la
presi�n y temperatura para calcular la concentraci�n de CO(2) disuelto. Estos
m�todos no son espec�ficos para gas carb�nico y miden todos los gases disueltos,
incluyendo ox�geno y nitr�geno. Se ha desarrollado un sensor novedoso que mide
CO(2) �nicamente y puede ser utilizado para mediciones en linea. El sistema se
basa sobre la espectroscop�a infrarroja y el sensor usa un sistema de muestreo
de reflectancia total atenuada (ATR) para continuamente analizar una bebida en
aplicaciones tanto de flujo como sin flujo. El sensor es compacto y est�
dise�ado para que se ajuste al proceso. El desarrollo de este sensor tipo ATR se
compara con dispositivos tradicionales basado sobre presi�n/temperatura. Este
sensor ofrece una mejorada precisi�n que es independiente del tipo de cerveza,
densidad o contenido de alcohol. No es afectado por cambios fuertes de presi�n
en la l�nea y puede ser operado durante los ciclos de CIP.
Palabras claves: gas carb�nico, IR-med, medici�n de CO(2) en-l�nea,
tecnolog�a ATR
