Free chlorine measurement package is designed to eliminate cost and complexity in the chlorine analysis of fresh water
Emerson Process Management has announced the Rosemount Analytical model FCL free chlorine measurement system, designed to eliminate cost and complexity in the chlorine analysis of fresh water.
The FCL described as the industry's first complete chlorine measurement package, including a sensor, connecting cable, analyser and panel-mounted flow controller - ready for immediate installation.
In addition, the FCL does not require sampling systems and messy reagents for the control of pH, since the analyser automatically compensates for changes in the pH of the sample - a significant time and money-saving capability.
The packaged design of the FCL simplifies installation in the field, and also eliminates the need for multiple orders from multiple suppliers with the potential that parts may not work together. According to John Wright, vice president of the Rosemount Analytical business of Emerson Process Management, "Contractors and users have really driven the creation of the model FCL fully packaged free chlorine system.
"All of these parts have been pre-selected to work together optimally in water applications." The one-step ordering and simple installation are said to save hours of time and energy.
The Rosemount model FCL uses a membrane-covered amperometric sensor that, like all such sensors, measures hypochlorous acid.
Free chlorine, however, is a pH-dependent mixture of hypochlorous acid and hypochlorite ion: a change in pH will cause the sensor response to change, even though the free chlorine level remains constant, producing an incorrect measurement.
Most systems solve the problem by treating the sample with acid, which lowers the pH and converts the hypochloride ion into hypochlorous acid.
FCL, however, avoids the inconvenience of sample conditioning and the cost of reagents by measuring the pH and applying a correction to the raw chlorine sensor signal.
Considering that most water installations include multiple free chlorine sensors mounted throughout the plant - and even miles from each other - the elimination of the sampling step said to be a notable step forward in efficiency.
The FCL includes the easy-to-use model 1055 analyser that features two fully programmable 4-20mA outputs and three fully programmable relays.
Sensors are easily replaced due to the Variopol quick-disconnect fittings.
The large, back-lit two-line display allows the user to read sample pH and chlorine concentrations at a glance.
