Model FCL-56 Engineering Specification
1. The system shall be suitable for the determination of free
chlorine in water having conductivity greater than about 50
uS/cm at 25°C and pH between about 5.5 and 9.5 without the
use of reagents.
2. The system shall consist of an analyzer, a free chlorine sensor, a
pH sensor (if required), flow cells for each sensor, and a flow
controller. The components shall be mounted on a back plate.
Sensor cables shall be pre-wired to the analyzer. Sensors shall
plug into the cables using Variopol quick disconnect fittings.
The sensor flow cells shall be clear plastic to allow the sensors to
be easily inspected for fouling. The inlet shall be fitted with a
check valve to ensure the sensors remain wet in the event sample
flow is lost.
3. The system shall use no mechanical devices, such as pressure
regulators, valves, or rotameters, to control flow. In-stead, flow
shall be regulated using a constant head flow controller.
Minimum sample flow shall be no more than about 3 gallons per
hour (11 liters per hour). Maximum flow can be as high as
80 gallons per hour (303 liters per hour). The flow controller
shall be able to handle inlet pressure between 3 and 65 psig (122
to 549 kPa abs) and temperature between 32 and 122°F (0 and
50°C).
4. The free chlorine sensor shall be a two-electrode, membranecovered amperometric sensor. The free chlorine sensor shall be
fitted with an RTD to allow continuous correction for changes in
membrane permeability caused by temperature. The linear range
of the free chlorine sensor shall be at least between 0 and 10 ppm
as Cl2.
5. The pH sensor shall be a combination electrode having a glass
sensing membrane and a double junction reference electrode.
6. The pH sensor shall be required if the pH of the sample varies
more than about 0.2 units peak-to-peak. For pH variations less
than 0.2, the pH sensor shall generally not be required.
7. The analyzer shall have dual input, one for the free chlorine
sensor and the other for the pH sensor (if needed). The analyzer
shall receive the raw signal from the free chlorine sensor and
automatically correct it for temperature and pH effects. Results
shall be displayed as ppm Cl2.
8. The analyzer shall require single point calibration. A correction for
the sensor zero current shall also be available.
9. The analyzer shall have automatic buffer recognition for pH
sensor calibration.
10. The analyzer shall have a four line, full color display. The display
shall show ppm chlorine, pH (if required), and temperature on one
screen. The display shall be programmable to show additional
information such as raw sensor current.
11. The analyzer shall be capable of operating between 14 and
140°F (-10 and 60°C) and between 5 and 95% relative
humidity (non-condensing).
12. The analyzer shall have four 0/4-20 mA isolated outputs and
HART digital communications. Outputs shall be fully scalable
and
assignable
independently to chlorine, pH, or temperature. PID
control shall be available as a standard fe ature.
13. The analyzer shall have four alarm relays fully programmable as
a high/low alarm with adjustable deadband or as a timer. Timer
functions shall include an interval timer, bleed and feed timer,
delay timer, and date and time timer. Time- proportional
control shall also be available. In addition relays shall be
configurable to energize when the analyzer detects a fault with
itself or the sensor.
14. All analyzer programming shall be through a front panel
membrane keypad. The language (English, Spanish, Italian,
Portuguese, German, French, Russian, Polish, or Chinese) shall
be selectable by the user.
15. The analyzer shall have a data logger that automatically stores
data every thirty seconds for thirty days with older data being
discarded to make room for
newer
data. In addition to storing date
and time, chlorine concentration, pH, and temperature, the
analyzer will store raw sensor current (chlorine sensor) and mV
reading and glass and reference impedance (pH sensor). Stored
data shall be downloadable through a USB port.
16. The analyzer shall have a dual graphical display that allows
stored data to be viewed over one hour, one day, seven days,
and one month intervals.
17. The
analyzer shall have a data logger that stores up to 300
events.
18. The analyzer shall have help screens, available at the touch of a
button, that provide information about configuration,
calibration, and troubleshooting.
19. The analyzer shall have a security feature to prevent unautho-
rized tampering with calibration and configuration settings.
20. The analyzer shall be Rosemount Model
FCL-01-
240 (free
chlorine only) or Model FCL-02-241 (free chlorine with
continuous pH correction) or approved equal.