Technical
Information
TI 114C/24/ae
Sensors for chlorine dioxide
CCS 240 and CCS 241
Membrane-covered, amperometric sensors
for installation in the CCA 250 flow holder
The CCS 240 chlorine dioxide sensor is
suitable for applications with a measuring range of 0.05 to 20 mg ClO2/l
(1 mg/l = 1 ppm). The CCS 241 chlorine
sensor is especially suitable for disinfection, of drinking water conditioning, or for
the detection of chlorine dioxide traces
in the range of 0.01 to 5 mg CIO2/l
(1 mg/l = 1 ppm).
The dissolved chlorine dioxide concentration after production in the sodium
chlorite/hydrochloric acid (NaCIO2/HCI)
or sodium chlorite/chlorine gas
(NaCIO2/CI2) process can be measured.
Areas of application
Drinking, industrial, and swimming pool
water must be disinfected with suitable
oxdizing agents such as chlorine
dioxide.
The dosing of the appropriate oxidizing
agents must be carefully controlled to
suit the application.
Too low a concentration makes the
degree of disinfection questionable; too
high a concentration can result in
corrosion effects, impairment of taste, or
skin irritation.
Benefits at a glance
• Minimum flow rate for installation in
the CCA 250 flow holder: 8 gal/h
(30 l/h)
• Measurement almost independent of
flow rate in the range above 8 gal/hr
(30 l/h)
• No zero point calibration necessary;
so the complicated installation of an
active carbon filter, as in open
chlorine sensors, is unnecessary
• Measured values are not affected by
conductivitiy fluctuation
• The CCS 240 sensor is ready for
measurement after a polarization time
of approximately 10 to 30 minutes; the
CCS 241 sensor requires 45 to 90
minutes
• Ready-made membrane head allows
simple membrane change
• Re-calibration intervals are
approximately 1 to 4 months under
constant operating conditions
• Outlet up to 15 psig (1 bar) back
pressure
The Power of Know How
Measuring system
The membrane-covered amperometric
sensors CCS 240 or CCS 241 are
designed for mounting in the CCA 250
flow holder. Sensors are connected to
the CCM 223 / 253 Chlorine Analyzer.
Chlorine analyzer
Liquisys M CCM 253
field enclosure
CCS 240 / 241
Chlorine sensor
OR
ENDRESS+HAUSER
LIQUISYS S
Mounting points for pH
and ORP electrode
REL 1
ALARM
CAL
CCA 250
Flow holder
REL
REL 2
Chlorine analyzer
Liquisys M CCM 223
panel mount
REL 1
E
REL 2
ENDRESS+HAUSER
LIQUISYS
REL 1
Inductive proximity
switch for flow
control
Measuring water
outlet
ALARM
CAL
REL
REL 2
REL 1
E
REL 2
Flow plummet
Sampler cock for
DPD measurement
Measuring water feed
(sample flow)
Drain and
calibration cap
Main flow
Operating principle
The membrane-covered sensor consists
of a cathode serving as the working
electrode, and an anode acting as the
counter electrode. These electrodes are
immersed in an electrolyte. Electrodes
and electrolyte are separated from the
medium to be measured by a membrane. This membrane prevents the loss
of electrolyte and penetration of contaminants which can cause “poisoning.” A
fixed polarization voltage is applied
between the anode and the cathode.
Dimensions
Æ
0.47"
(12)
0.26"
(6.5)
6.30"
(160)
3.46"
(88)
2.91"
(74)
Æ0.98
"
(25)
CCS 240 / 241
dimensions are
in inches (mm)
Æ 1.14"
(29)
Æ 1.42"
(36)
When the sensor is immersed in
chlorinated water, chlorine dioxide
diffuses through the membrane. The
molecules impinging on the cathode
(electron surplus) are reduced to
chloride ions. At the anode, silver is
oxidized to silver chloride. The resulting
maximum diffusion current is a direct
measure of the concentration of free
chlorine dioxide.
Technical data
Measuring system
Passively operated sensor with gold cathode
and silver/silver chloride anode
Shaft material
PVC
Membrane material
PTFE
Membrane cap
Replaceable
Cable connection
15 foot (3 m) 4-wire, double-shielded cable,
low noise
Polarization time
CCS 240, first polarization 30 minutes;
re-polarization, 10 minutes
CCS 241, first polarization 90 minutes;
re-polarization, 45 minutes
Measuring range
CCS 240, 0.05 to 20 ppm ClO2
CCS 241, 0.01 to 5 ppm ClO2
Response time
90% of final value: < 2 min.,
99% of final value: < 5 min.
Minimum flow rate
For CCA 250 flow holder, 8 gal/h (30 l/h)
Minimum flow velocity
6 in/s (15 cm/s)
Permissible temperature range
CCS 240 / CCS 241, 35° to 113°F (2° to 45°C)
pH value range
CCS 240 / CCS 241 in stability range of CIO2
Maximum back pressure
15 psig (1 bar)
Filling electrolyte lifetime
Typically 12 months average
Temperature sensor
NTC, 10 kΩ at 77°F (25°C)
Subject to modifications.
Ordering information
CCS 240 Chlorine dioxide sensor
1
CCS 240 1
Version
N With NTC temperature sensor
CCS 241 Chlorine dioxide trace sensor
1
CCS 241 1
Version
N
With NTC temperature sensor
Accessories
• CCY 14-WP
2 replacement cartridges ready-made for CCS 240 / 241 sensors
Order no. 50005255
• CCY 24-F
50 ml electrolyte ready-made for CCS 240 / 241 sensors
Order no. 50064294
Supplementary
documentation
Technical information
CCA 250 Flow holder for free chlorine and chlorine
dioxide sensors:
CCM 181 microprocessor photometer for chlorine
and chlorine dioxide detection:
CCM 223 / 253 Liquisys M chlorine analyzer:
CCE 1 / CCE 3 Compact chlorine measuring station:
TI 062C/24/ae
TI 121C/24/ae
TI 214C/24/ae
TI 014C/07/en
For application and selection assistance,
in the U.S. call 888-ENDRESS
For total support of your installed base, 24 hours
a day, in the U.S. call 800-642-8737
Visit us on our web site, www.us.endress.com
United States
Canada
Mexico
Endress+Hauser, Inc.
2350 Endress Place
Greenwood, IN 46143
Phone: (317) 535-7138
888-ENDRESS
FAX: (317) 535-8498
Endress+Hauser
Canada Ltd.
1440 Graham’s Lane
Unit 1, Burlington
ON, L7S 1W3
Phone: (905) 681-9292
800-668-3199
FAX: (905) 681-9444
Endress+Hauser
Paseo del Pedregal No. 610
Col. Jardines del Pedregal
01900, Mexico D.F.
Mexico
Phone: (525) 568-2405
FAX: (525) 568-7459
Endress+Hauser
The Power of Know How
TI 114C/24/ae/05.02
© 2002 Endress+Hauser, Inc.