Description And Specifications; Features - Emerson Rosemount MCL-220 Manual

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Description and Specifications

2.1

Features

The Rosemount MCL monochloramine system is intended for measuring monochloramine
in fresh water.
This system uses a membrane-covered amperometric sensor. A polarizing voltage applied
to a gold mesh cathode behind the membrane destroys the monochloramine diffusing
through the membrane and keeps the concentration of monochloramine in the sensor
equal to zero. The current generated by the cathode reaction is proportional to the rate of
diffusion of monochloramine through the membrane. Because the concentration of
monochloramine in the sensor is zero, the diffusion rate and the current are proportional
to the concentration of monochloramine in the sample.
Diffusion rate also depends on membrane permeability, which is a function of
temperature. An RTD in the sensor continuously measures the temperature of the sample,
and the transmitter automatically corrects the raw sensor current for temperature
changes.
Maintenance is fast and easy. Replacing a membrane requires no special tools or fixtures. A
screw cap holds the pre-tensioned membrane in place. Replacing the electrolyte solution
takes only minutes.
The Rosemount MCL-220 system includes an easy-to-use Rosemount 1056 transmitter
that features two fully programmable 4-20 mA outputs and four fully programmable
relays. The large back-lit display allows you to read monochloramine concentration at a
glance.
A constant head overflow sampler ensures correct sample flow to each sensor.
Stable monochloramine standards do not exist. The monochloramine sensor must be
calibrated using the results of a laboratory test run on a grab sample.
Instruction Manual
Description and Specifications
5