JUMO tecLine ClO2 / JUMO tecLine O3
Sensors for chlorine dioxide and ozone
Type 202634/45, type 202634/46
type 202634/50, type 202634/51
B 202634.0
Operating manual
2012-07-13/00585740
Screws coated with threadlocking paint must not be adjusted! The
threadlocking paint must not be damaged. If it is, claims under the
warranty will not be honored!
Contents
1 Typographical conventions ...................................................... 5
1.1 Warning signs ..............................................................................................5
1.2 Note signs ....................................................................................................5
2 General ....................................................................................... 6
2.1 Preface .........................................................................................................6
2.2 Scope of application ....................................................................................6
2.3 Output signal ................................................................................................6
3 Device identification ................................................................. 7
3.1 Nameplate ....................................................................................................7
3.2 Order details .................................................................................................7
4 Description ................................................................................ 8
4.1 Scope of delivery .........................................................................................8
4.2 Sensor for chlorine dioxide - type 202634/45 ..............................................8
4.3 Sensor for chlorine dioxide - type 202634/46
(resistant to chemicals and surfactants) ......................................................8
4.4 Sensor for ozone - type 202634/50 .............................................................8
4.5 Sensor for ozone - type 202634/51
(resistant to chemicals and surfactants) ......................................................9
4.6 Details ..........................................................................................................9
4.7 Technical data ............................................................................................11
5 Mounting .................................................................................. 13
5.1 Notes ..........................................................................................................13
5.2 Flow-through fitting (part no. 00392611) ...................................................14
5.3 Flow monitoring .........................................................................................16
6 Electrical connection .............................................................. 17
6.1 Sensor for chlorine dioxide or ozone .........................................................17
6.2 Flow monitor ..............................................................................................18
6.3 Example of a measurement section ...........................................................19
7 Startup ..................................................................................... 21
7.1 Screwing the membrane cap off and on ....................................................21
7.2 Topping up reference electrolyte ...............................................................21
Contents
8 Maintenance ............................................................................ 27
8.1 Cleaning the electrode finger tip / replacing the membrane cap and
electrolyte ...................................................................................................27
8.2 Remove scale that has accumulated on the membrane cap ....................28
8.3 Storage / transport .....................................................................................28
8.4 Consumables / accessories .......................................................................29
9 Calibration ............................................................................... 30
9.1 General .......................................................................................................30
9.2 Calibration with a indicator/control instrument ..........................................30
10 Eliminating errors and faults .................................................. 32
1.1 Warning signs
Caution
This sign is used when there may be danger to personnel if the instructions
are ignored or not followed correctly!
Attention
This sign is used when there may be damage to equipment or data if the
instructions are ignored or not followed correctly!
1.2 Note signs
Note
This sign is used to draw your attention to something of special importance.
1 Typographical conventions
1
abc
✱ Action instruction
Footnote
Footnotes are remarks that refer to specific points in the text. Footnotes
consist of two parts:
Identification marking in the text and the footnote text.
The identification markings in the text are arranged as sequential superscript
numbers.
This sign indicates that an action to be performed is described.
The individual steps are marked by this asterisk.
Example:
✱ Press key.
5
2 General
2.1 Preface
Please read this operating manual before placing the device in operation.
Keep the operating manual in a place which is accessible to all users at all
times.
Danger:
Sudden failure of the sensor may result in dangerous overdosing of chlorine
dioxide or ozone. Suitable preventive measures must be in place as needed to
prevent this from happening.
Check the plant for odor of chlorine dioxide or ozone and check water for any
unusual discoloration.
2.2 Scope of application
These membrane-covered, amperometric sensors are used to measure the
concentration of chlorine dioxide and ozone (for example in drinking and
swimming water, industrial, process and cooling water).
The sensor for chlorine dioxide can be used to measure chlorine dioxide from
chlorite / chlorine and chlorite / hydrochloric acid plants.
The sensor for ozone can be used for example to measure electrolytically
generated ozone.
The sensors are not suitable for detecting the absence of chlorine dioxide and
ozone.
The integrated electronics of the sensors provides a temperaturecompensated current signal of 4 to 20mA. A downstream device (indicator,
controller, recorder, PLC, etc.) is used for calibration.
2.3 Output signal
Since the measurement signal of amperometric sensors is temperaturedependent, an integrated NTC resistor is provided for automatic temperature
compensation. The recommended temperature ranges are as follow
- For sensors of types 202634/45 and 202634/50): +5 to +45 °C.
- For sensors of types 202634/46 and 202634/51): +5 to +50 °C.
The integrated electronics of the sensors provides a current signal of 4 to
20 mA.
A downstream device (indicator, controller, recorder, PLC, etc.) is used for
calibration.
The sensors can be connected directly to a suitable indicator and controller.
The JUMO AQUIS 500 AS indicator/controller (type sheet 202568) and the
JUMO dTRANS AS 02 indicator/controller (type sheet 202553) are especially
suitable for combining with these sensors. They provide the voltage required
for the power supply of the sensor and make for an easy way to calibrate the
measuring system.
6
3.1 Nameplate
Sensor for chlorine dioxide
Type: 202634/45-20
Measuring range: 0.00 to 2.00 mg/l
F No. 00000000 00 0 1226 0005
Serial No.: 01 01 0002
JUMO tecLine ClO2
JUMO GmbH & Co. KG
Fulda, Germany
www.jumo.net
Note:
The date of manufacture is encoded in the "F No." (manufacturing number):
1226 signifies: year of manufacture 2012 / calendar week 26.
3.2 Order details
(1) Basic type
202634 Sensor
3 Device identification
(2) Basic type extension
45 for chlorine dioxide
46 for chlorine dioxide (resistant to chemicals and surfactants)
50 for ozone
51 for ozone (resistant to chemicals and surfactants)
(3) Measuring range
o o 10 0.00 to 0.50 mg/l (ppm)
oooo 20 0.00 to 2.00 mg/l (ppm)
25 0.00 to 5.00 mg/l (ppm)
35 0.00 to 10.00 mg/l (ppm)
o o 37 0.00 to 20.00 mg/l (ppm)
(1) (2) (3)
Order code /-
Order example 202634 / 45 - 20
7
4 Description
4.1 Scope of delivery
Two-wire sensor with membrane cap, electrolyte and special abrasive paper
for cleaning the electrode finger.
4.2 Sensor for chlorine dioxide - type 202634/45
This sensor features a membrane-covered, amperometric 2-electrode
measuring system.
The membrane of this sensor is made of hydrophobic, microporous PTFE
material. These sensors should only be used in water with drinking or
swimming pool quality. The water should not under any circumstances contain
surfactants (many cleaning agents and disinfectants contain surfactants).
Surfactants will eliminate the hydrophobic properties of the membrane. Then
proper functioning can no longer be guaranteed.
The membrane cap that seals off the electrode space is filled with an aqueous
electrolyte containing alkali halides.
The working electrode (cathode) is made of gold (Au). The anode, which
performs the function of a combined reference electrode and counter
electrode, is made of silver (Ag) fitted with a coating of silver halide (AgHal).
The sensor for chlorine dioxide can be used to measure chlorine dioxide from
chlorite/chlorine and chlorite/hydrochloric acid plants.
4.3 Sensor for chlorine dioxide - type 202634/46 (resistant to chemicals and surfactants)
The sensor measures chlorine dioxide from chlorite/chlorine plants and
chlorite/hydrochloric acid plants.
4.4 Sensor for ozone - type 202634/50
This sensor features a membrane-covered, amperometric 2-electrode
measuring system.
The membrane of these sensors is made of hydrophobic, microporous PTFE
material. This sensor should only be used in water with drinking or swimming
pool quality. The water should not under any circumstances contain
surfactants (many cleaning agents and disinfectants contain surfactants).
Surfactants will eliminate the hydrophobic properties of the membrane. Then
proper functioning can no longer be guaranteed.
The membrane cap that seals off the electrode space is filled with an aqueous
electrolyte containing alkali chlorides.
The working electrode (cathode) is made of gold (Au). The anode, which
performs the function of a combined reference electrode and counter
electrode, is made of silver (Ag) fitted with a coating of silver halide (AgHal).
The sensor for ozone can be used to measure electrolytically generated
ozone.
8
4.5 Sensor for ozone - type 202634/51
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
(resistant to chemicals and surfactants)
This sensor measures ozone, for example electrolytically generated ozone
). This sturdy sensor can be used in all water qualities.
(O
3
4.6 Details
4.6.1 Types 202634/45 and 202634/50
4 Description
(1) Pg screw connection
(2) Cover
(3) O-ring
(4) 2-pin terminal for measuring cable connection
(5) Electrode shaft with integrated electronics
(6) O-ring
(7) Electrode finger (reference electrode)
(8) Measurement electrode
(9) Transparent cover
(10) Membrane cap
(11) PTFE membrane
(12) Valve opening
9
4 Description
(1)
(2)
(3)
(4)
(5)
(7)
(8)
(9)
(10)
(11)
(13)
(14)
(12)
(6)
Attention:
- This measurement is only possible in a suitable flow-through fitting
(part no. 00392611).
- The process medium must be similar in quality to drinking or swimming
pool water.
- The sample medium must not contain any surfactants (surface-active
substances, for example those in cleaning agents, detergents and
disinfectants).
- The process medium must not contain any hydrophobic substances
(for example oils and greases).
4.6.2 Types 202634/46 and 202634/51
10
(1) Pg screw connection
(2) Cover
(3) O-ring
(4) 2-pin terminal for measuring cable connection
(5) Electrode shaft with integrated electronics
(6) Counter electrode (stainless steel)
(7) O-ring
(8) Electrode finger (reference electrode)
(9) Measurement electrode
(10) Transparent cover
(11) Membrane cap
(12) Membrane holder (stainless steel)
(13) Membrane
(14) Valve opening
4.7 Technical data
≤
UB – 7.5 V
0.02A
4.7.1 Types 202634/45 and 202634/50
4 Description
Analyte Chlorine dioxide (ClO2)Ozone (O
Membrane type Hydrophobic PTFE membrane
Measuring cable connection 2-pin terminal, polyamide PG7 screw connection; conductor cross section 2x 0.25 mm
Voltage supply U
Electromagnetic
compatibility
Output signal 4to20mA
Burden
Settling time 1h 2h
Incident flow velocity approx. 15cm / s
Measuring ranges
(other ranges on
request)
Resolution 0.001mg / l, for measurement range 0 to 0.5mg/l;
Response time t
Operating temperatures /
temperature compensation
Zero point adjustment Not required
pH value operating range 1to11pH 2to11pH
pH dependency
(loss of slope)
Disruptive substances /
cross sensitivities
Pressure resistance p
Material Shaft, cover, cap: PVC Shaft, cover, cap: PVC
Dimensions Diameter: 25 mm, length: 220 mm
Weight approx 125 g
Maintenance
90
Check the measurement signal:regularly, at least once a week
0to2.0/0to5/0to10mg/l (ppm)
Type 202634/45 Type 202634/50
12 to 30V DC (electrical isolation recommended)
B
Interference immunity: To industrial requirements
If the sensor is installed in a JUMO flow-through fitting 00392611,
this is equivalent to a flow rate of about 30l / h.
approx. 15 s approx. 15 s
+5 to +45 °C +5 to +45 °C
Chlorine is disruptive
Ozone is disruptive
No pressure fluctuations are admissible when operating under pressure.
0.01mg / l, for measurement range 0 to 2.0mg / l
We recommend unpressurized operation (atmospheric pressure).
According to EN 61326-1
Interference emission: Class B
No pH dependency
max. 2 bar
abs
p
max. 1 bar
rel
0to0.5/0to2.0/0to5/ 0to10
mg / l (ppm)
Chlorine is disruptive
Chlorine dioxide is disruptive
)
3
2
, cable diameter approx. 4 mm
Replace the membrane cap:once a year (subject to water quality)
Change the electrolyte: every 3 to 6 months
Storage
Sensor: frost-free, dry and without electrolyte, can be stored for an unlimited time at
+5 to +45 °C
Membrane cap: Used membrane caps cannot be stored!
Electrolyte: In the original bottle and protected against sunlight at +5 to +25 °C
11
4 Description
≤
UB – 7.5 V
0.02A
4.7.2 Types 202634/46 and 202634/51
Analyte Chlorine dioxide (ClO2)Ozone (O
Membrane type Membrane resistant to chemicals and surfactants
Measuring cable connection 2-pin terminal, polyamide PG7 screw connection; conductor cross section 2x 0.25 mm
Voltage supply U
Electromagnetic
compatibility
Output signal 4to20mA
Burden
Settling time 1h 1h
Incident flow velocity approx. 15cm / s
Measuring ranges
(other ranges on
request)
Resolution 0.001mg / l, for measurement range 0 to 0.5mg/l;
Response time t
Operating temperatures /
temperature compensation
Zero point adjustment Not required
pH value operating range 1to11pH 2to11pH
pH dependency
(loss of slope)
Disruptive substances /
cross sensitivities
Pressure resistance p
Material Shaft, cover, cap: PVC
Dimensions Diameter: 25 mm, length: 220 mm
Weight approx 125 g
Maintenance
90
Check the measurement signal: regularly, at least once a week
Type 202634/46 Type 202634/51
12 to 30V DC (electrical isolation recommended)
B
Interference immunity: To industrial requirements
If the sensor is installed in a JUMO flow-through fitting 00392611,
this is equivalent to a flow rate of about 30l / h.
approx. 1.5 min approx. 50 s
Chlorine is not disruptive
Ozone is disruptive
No pressure fluctuations are admissible when operating under pressure.
0.01mg / l, for measurement range 0 to 2.0mg / l
We recommend unpressurized operation (atmospheric pressure).
According to EN 61326-1
Interference emission: Class B
0 to 2.0mg / l (ppm)
+5 to +50 °C
No pH dependency
max. 2 bar
abs
max. 1 bar
p
rel
Membrane disk holder:
Stainless steel
Chlorine is disruptive
Chlorine dioxide is disruptive
)
3
2
, cable diameter approx. 4 mm
Replace the membrane cap: once a year (subject to water quality)
Change the electrolyte: every 3 to 6 months
Storage
Sensor: Frost-free, dry and without electrolyte, can be stored for an unlimited time at
+5 to +45 °C
Membrane cap: Used membrane caps cannot be stored!
Electrolyte: In the original bottle and protected against sunlight at +5 to +25 °C
12
5.1 Notes
5 Mounting
Attention:
- The measurement is only possible with a suitable flow-through fitting (for
example a flow-through fitting for sensors according to type sheets 202630,
202631, 202634, 202636, part no. 00392611, see type sheet 202634).
- The sensor should be operated unpressurized if possible with free
discharge of the process medium. If that is not possible, the sensor can
also be operated at a constant pressure of up to 1 bar (p
Pressure fluctuations must be prevented!
- Air bubbles upstream from the membrane can distort the measurement
signal.
- Both the transmitter and the sensor connected to it must remain
continuously in operation even if the system is only operated at intervals.
The supply voltage of the connected sensor must not be turned off!
- The sensor must not be left dry.
) or 2 bar (p
rel
abs
).
13
5 Mounting
(4)
(3)
(5)
(1)
(2)
5.2 Flow-through fitting (part no. 00392611)
5.2.1 Mounting the fitting
The flow-through fitting can be fastened to a wall with an optional support
bracket (part no. 00455706) or fastened to an installation table.
14
(1) Sensor
(2) Support bracket (optional)
(3) Connection G1/4 for hose ø 8mm x 6mm
(4) Fitting
(5) Removable measuring vessel (inspection glass)
5.2.2 Sensor installation
(1)
(2)
(5)
(6)
(4)
(8)
(10)
(9)
(7)
(3)
Overview
5 Mounting
Installation
(1) Sensor (6) Inspection glass
(2) Union nut (7) Inlet G1/4A or DN10
(3) Flow-through fitting (8) Stepped collar 1"
(4) Outlet G1/4A or DN10 (9) Compression ring
(5) O-ring (10) O-ring
1
Part of the fitting.
Caution: When assembling and installing the sensor (1) make certain the O-
1
1
1
rings and threads are clean and fully operational!
The transparent inspection glass (6) can be unscrewed from the fitting housing
for maintenance purposes.
1. First push the O-ring (10) onto the sensor (1), then the compression ring (9)
and over it the 1" stepped collar (8) (starting from the Pg screw connection).
The stepped collar (8) must engage in the groove.
15
5 Mounting
(3)
(1)
(2)
2. After the sensor has been prepared in this manner, insert it into the flowthrough fitting (3) and fasten it in place with the union nut (2).
5.3 Flow monitoring
5.3.1 Minimum inflow
For proper operation, the incident flow of the process medium on the sensor
must be at least 15 cm/s. This corresponds to a minimum flow rate of 30 l/h in
the flow-through fitting.
Below this minimum incident flow velocity, the sensor will indicate values that
are too low. This could result in dangerous overdosing in a connected control
system.
Above this minimum incident flow velocity the measurement signal is only
slightly affected by the incident flow velocity.
The monitoring system consists of a flow fitting (2) part no.: 00396470 and the
flow monitor (1) (part no.: 00396471), See section 5.3.2 "Mounting", page 16.
The instrument can be used to monitor the minimum incident flow velocity of
15 cm/s.
5.3.2 Mounting
16
The O-ring (3) must be resting in the groove of the flow monitor (1).
1. Screw the flow monitor (1) into the fitting (2).
6 Electrical connection
(1)
(2)
(3)
(4)
6.1 Sensor for chlorine dioxide or ozone
6.1.1 General
- Cable diameter approx. 4 mm
- Wire cross section 2 x 0.25mm
- Lay signal lines isolated from cables with voltages of > 60 V
- Use a shielded cable with twisted wires
- Keep clear of large electrical installations
6.1.2 Terminal assignment
Connection Screw terminals
Voltage supply
DC 12 to 30 V
2
1 L+
2 L-
Output
4 to 20 mA two wires
Impressed current 4 to 20 mA in voltage
supply
6.1.3 Connection
1 L +
2 L-
1. Push the cover (2) over the connecting cable.
2. Connect the wires to the terminals (4) according to the terminal assignment.
3. Screw on the cover (2) by hand until the O-ring (3) seals.
4. Tighten the Pg screw connection (1).
Attention:
When disconnecting, undo the Pg screw connection (1) first!
17
6 Electrical connection
4
1
3 -
NC
C
br
ws
NO
gn
signal
1
4
3
2
Stecker 4polig
6.2 Flow monitor
6.2.1 Function
The contact (3+4) is opened starting at a flow velocity of 15 cm/s.
18
6 Electrical connection
4
1
3
+
-
1
4
3
2
(A)
(B)
(3)
(4)
(1)
6.3 Example of a measurement section
6.3.1 Sensor
The electronics integrated into the shaft of the sensor (2) returns an
uncalibrated 4 to 20 mA signal.
6.3.2 Indicator/controller
The signal can be further processed with the JUMO AQUIS 500 AS (1) or the
JUMO dTRANS AS 02. The device provides the required supply voltage and
makes for an easy way to calibrate the measuring system. The sensor can also
be connected to other indicator, controller, recorder or PLC systems, however,
provided the power supply and calibration allow it.
6.3.3 Connection
Danger:
Before making the connection, always read the JUMO AQUIS 500 AS
(B 202568) operating manual!
(1) JUMO AQUIS 500 AS, type 202568/20-888-888-888-310-310-23/000,
see type sheet and operating manual 202568
(3) Sensor for chlorine dioxide or ozone, see data sheet 202634
(4) Optional flow monitor part no.: 00396471,
see type sheet 202634
(A) Row 1
(B) Row 2
19
6 Electrical connection
(1)
(2)
(3)
6.3.4 Flow monitor
If the flow monitor (3) indicates too small a flow from the sensor (2), the binary
input of the JUMO AQUIS 500 AS (1) switches, the instrument goes to "Hold"
and an alarm is generated.
(1) JUMO AQUIS 500 AS, type 202568/20-888-888-888-310-310-23/000,
see type sheet and operating manual 202568
(2) Sensor for chlorine dioxide or ozone, see data sheet 202634
(3) Flow monitor part no.: 00396471, see type sheet 202634
20
7.1 Screwing the membrane cap off and on
(1)
(3)
(2)
(4)
(5)
(6)
(7)
(8)
Caution: The electrolyte may spray out of the valve opening (5) when the
membrane cap is screwed on! Wear safety goggles!
Wash off sprayed liquid (aqueous solution of an alkali halide) under flowing
water.
Attention:Before screwing off the membrane cap, move the transparent
cover(s) (6) to the side so that the valve opening (5) is exposed! Otherwise the
membrane will be destroyed.
Do not touch the electrode finger (3/4) or get it dirty!
The steps must be performed exactly as they are described below!
The membrane of the sensor is very sensitive. Make certain when screwing the
membrane cap on and off that the membrane is not destroyed by vacuum or
excess pressure.
The service life of the electrolyte is about 3 to 6 months.
Types 202634/45 and /50 have one transparent cover (6).
Types 202634/46 and /51 have two transparent cover (6).
7 Startup
7.2 Topping up reference electrolyte
7.2.1 For types 202634/45 and /50
21
7 Startup
1. Use a small screwdriver or similar tool to raise the transparent cover (6) of
the valve opening (5) close to the valve opening and push it somewhat to
the side. The valve opening (5) is now open.
2. Screw the membrane cap (7) off the shaft (1) of the sensor.
3. Push the transparent cover (6) back in place until the cover
is resting in the slot again and the valve opening closes.
4. Discard the used electrolyte, clean the membrane cap with clean water and
then dry it.
5. Fill the membrane cap (7) up to the brim with enclosed electrolyte with no
bubbles.
6. Holding the shaft (1) of the sensor vertically, tightly screw it (manually) onto
the filled membrane cap (7), making certain as you do so that no excess
electrolyte can escape from the valve opening (5).
22
7 Startup
Attention:
Always wait before screwing the membrane cap onto the sensor until just
before it is installed in a fitting! The sensor is very sensitive when it is
completely assembled!
When it is in a condition ready for measuring (membrane cap screwed on
completely), the sensor must not be pushed open with the membrane (8). This
will damage it and make it unusable!
Screw on the membrane cap (7) completely (as far as it will go)! The sealing Oring (2) offers the first resistance against screwing in the membrane cap.
Continue screwing in the membrane cap (7) until it is touching the shaft (1) of
the sensor!
23
7 Startup
(1)
(3)
(2)
(4)
(8)
(7)
(6)
(5)
7.2.2 For types 202634/46 and /51
The membrane cap comes in a can filled with water. This ensures that a layer of air
cannot form on the inside of membrane.
1. Open the can with the membrane cap, drain the water and remove the
membrane cap. There must only be one transparent cover (6) in the groove,
closing the valve opening (see arrow).
The second transparent cover must be visible as shown in the picture.
2. Fill the membrane cap (7) up to the brim with enclosed electrolyte.
If there are still air bubbles trapped in the membrane area (only visible against
backlight), please apply the tapping procedure described below. This can be
used to remove any air bubbles that may be trapped inside the membrane,
which would interfere with the measuring function:
24
2a.Tap with the electrode shaft on the filled membrane cap (7) until no more air
bubbles form and rise. This displaces a layer of air that may have formed on
the inside of the membrane. Then
add electrolyte. if necessary
7 Startup
3. Remove the black protective tube from the electrode finger (3). The enclosed
special abrasive paper is only used to clean the tip (4) of the dry electrode
finger (=measurement electrode). To do this hold the soft support with the
special abrasive paper and move the electrode tip (4) of the sensor over the
abrasive paper with the sensor at a slight angle. Then turn the sensor
slightly on its axis and move across the abrasive paper again. Repeat this
process several times.
4. Hold the electrode shaft vertically and place it on the filled membrane cap.
If necessary turn it counter-clockwise first until the thread engages, then
slowly screw the electrode shaft into the membrane cap. Excess
electrolyte will escape from the valve opening (5) during this process
not keep the valve opening (arrow) closed!
Make certain the membrane cap
electrode shaft
Attention:
The electrolyte may spray out of the valve opening (5).
Wash off spilled electrolyte or electrolyte that has gotten on the skin or in the
eyes with water.
The electrolyte may contain diluted acids.
Observe the warnings
! Flush off the electrolyte adhering to the outside with water.
on the electrolyte bottle!
is screwed (manually) tightly against the
. Do
25
7 Startup
Attention:
Always wait before screwing the membrane cap onto the sensor until just
before it is installed in a fitting! The sensor is very sensitive when it is
completely assembled!
When it is in a condition ready for measuring (membrane cap screwed on
completely), the sensor must not be pushed open with the membrane (8). This
will damage it and make it unusable!
Screw on the membrane cap (7) completely (as far as it will go)! The sealing Oring (2) offers the first resistance against screwing in the membrane cap.
Continue screwing in the membrane cap (7) until it is touching the shaft (1) of
the sensor!
7.2.3 Settling time
The sensor will not provide a constant value until after the settling time of
2 hours has passed. It cannot be calibrated until then.
The calibration procedure should be repeated on the day after initial
commissioning.
26
8 Maintenance
(1)
(3)
(2)
(4)
(8)
(7)
(6)
(5)
8.1 Cleaning the electrode finger tip / replacing the membrane cap and electrolyte
Attention:
Do not rub the brown coating on the combined counter electrode and
reference electrode (3) with special abrasive paper!
Do not touch the electrode finger (3/4) or get it dirty!
The steps must be performed exactly as they are described below!
1. Unscrew the membrane cap from the shaft of the sensor, See section 7.1
"Screwing the membrane cap off and on", page 21.
2. Clean the electrode finger (3) and membrane cap (7) with distilled water and
dry See section 7.2 "Topping up reference electrolyte", page 21.
3. Using the special abrasive paper, clean only the tip of the dried electrode
finger (4). To do this place the special abrasive paper on a cleaning tissue
with the matte side facing up, hold one corner firmly in place and while
holding the sensor vertically, move the electrode tip two or three times over
the special abrasive paper.
4. If necessary use a new membrane cap.
5. Fill the membrane cap (7) up to the brim with enclosed electrolyte with no
bubbles.
27
8 Maintenance
6. Screw the membrane cap onto the sensor shaft,
See section 7.1 "Screwing the membrane cap off and on", page 21.
Note:
The service life of the electrolyte is 3 to 6 months. The service life of the
membrane depends very much on the water quality.
Avoid heavy contamination of the membrane!
If the sensor still indicates values that are too low after the electrode finger tip
has been cleaned, a new membrane cap must be used.
8.2 Remove scale that has accumulated on the membrane cap
1. Unscrew the membrane cap from the shaft of the sensor, See section 7.1
"Screwing the membrane cap off and on", page 21.
2. Flush away the electrolyte.
3. Place the membrane cap (7) in a 1% solution of hydrochloric acid for a few
hours.
4. Before startup rinse off with clean water.
5. Screw the membrane cap filled with electrolyte onto the shaft of the sensor.
8.3 Storage / transport
Attention:
Used membrane caps that have been in operation for longer than 1 day
cannot be stored and reused!
Preparation
1. Unscrew the membrane cap from the shaft of the sensor, See section 7.1
"Screwing the membrane cap off and on", page 21.
2. Flush away the electrolyte.
3. Rinse off the membrane cap and electrode finger (3) with clean water and
dry so no dust is left.
4. Screw the dry membrane cap (7) loosely onto the electrode shaft (1). The
membrane (8) must not be resting against the electrode tip (4)!
Placing in operation again
1. Clean the electrode tip (4) with the enclosed special abrasive paper See
"Cleaning the electrode finger tip / replacing the membrane cap and
electrolyte", page 27.
2. Use a new membrane cap (7)!
28
8 Maintenance
8.4 Consumables / accessories
Designation Part no.
Flow-through fitting for sensors according to type sheets 202630, 202631, 202634,
202636
Support bracket for flow-through fitting 00455706
Flow monitor 00396471
Fitting for flow monitor 00396470
Special electrolyte for 202634/45 00392332
Special electrolyte for 202634/46 00441316
Special electrolyte for 202634/50 00392333
Special electrolyte for 202634/51 00441311
Spare parts set for 202634/45 and 202634/50 (1x membrane cap, fine abrasive
paper)
Spare parts set for 202634/46 (1x membrane cap, fine abrasive paper) 00409344
Spare parts set for 202634/51 (1x membrane cap, fine abrasive paper) 00441309
Matching indicator/controller: JUMO AQUIS 500 AS,
Type: 202568/20-888-888-888-310-310-23/000
(for other versions see type and price sheet 202568)
Matching transmitter / controller: JUMO dTRANS AS 02,
Type: 202553/01-8-01-4-0-00-23/000
(for other versions see type and price sheet 202553)
00392611
00392331
00528718
00550842
29
9 Calibration
9.1 General
Depending on requirements, the sensor should be checked and calibrated on
a regular basis at set time intervals. Recommendation: weekly or more
frequently depending on accuracy requirements.
Note:
The process for verification and calibration is as follows:
1. Take a sample of the medium in the immediate vicinity of the sensor.
2. Determine the concentration of the substance with a reference method.
3. Use the reference value that was determined to adjust the slope of the
indicator.
9.2 Calibration with a indicator/control instrument
Reference method
Note:
Suitable reference methods for calibrating can be found for example in
standards
- Chlorine dioxide: DIN 38408-5
Initial condition
Procedure
- Ozone: DIN 38408-3
The DPD method of photometric determination is frequently used (DPD = N,Ndiethyl-1,4-phenylenediamine). Suitable testing systems are commercially
available. Providers include VWR International (previously Merck)
(Spectroquant), Macherey-Nagel (Nanocolor) etc.
- The display format and measurement range have been set; see the
operating manual of the indicator/control instrument in use.
- The sensor is installed in a suitable flow-through fitting, See section 5
"Mounting", page 13.
- The settling time of the sensor (2 hours) has elapsed and the measured
value is stable.
1. Take a water sample at the flow-through fitting outlet (or in the immediate
vicinity of it).
2. Determine the analyte concentration (chlorine dioxide or ozone) of the
sample with a suitable reference method.
3. Adjust the indicator to the reference value; see the operating manual of the
transmitter/controller you are using.
30
Check the saved slope
Many transmitters/controllers (for example JUMO AQUIS 500 AS) have a
"calibration log". Relevant data from each calibration is saved in the log.
Attention:
If the value for the slope falls below 40%, the membrane cap and electrolyte
must be replaced and the electrode tip must be cleaned, See section 8.1
"Cleaning the electrode finger tip / replacing the membrane cap and
electrolyte", page 27.
Setting the slope manually
See the operating manual for the transmitter/controller you are using.
Zero-point adjustment
A zero-point adjustment is not required for the sensors described in this
operating manual. If there is no analyte present in the process medium,
approximately zero is indicated. The zero point is independent of changes in
the flow rate, conductivity, temperature and pH value.
9 Calibration
31
10 Eliminating errors and faults
Error/fault Possible cause Remedy Preventive
measures
(1) Sensor output
signal too high or too
low.
Incorrect calibration. Repeat calibration
using the DPD method
See "Initial condition",
page 30.
If necessary calibrate
the sensor more
frequently.
(2) Sensor output
signal is too low.
Sensor cannot be
adjusted to the DPD
value.
(3) Sensor output
signal is too low.
Sensor cannot be
adjusted to the DPD
value.
or else the sensor
output signal
decreases or remains
constant while the
DPD value increases
or the signal fluctuates
(4) Sensor output
signal is too high.
Sensor cannot be
adjusted to the DPD
value.
Settling time too short. Wait at least 2 hours
Deposit on the tip of
the electrode finger
(measuring electrode)
Incident flow on
sensor is too low.
Membrane destroyed:
Electrolyte escaping process medium
entering.
Effect of surfactants in
detergents and
cleaning agents on the
membrane. The
hydrophobic
properties of the
membrane are lost and
passage of water or
ions is possible.
Coating on the
membrane cap.
Gas bubbles on the
outside of the
membrane.
No electrolyte in the
membrane cap
In addition to the
analyte, the process
medium also contains
other oxidizing agents,
for example ClO
2
, O
Clean tip of electrode
finger.
Increase incident flow. Monitor minimum
Replace membrane
cap.
Replace membrane
cap. Replace the water
as well before using
the chlorine sensor
again (to eliminate all
traces of surfactants).
Replace membrane
cap.
Increase the flow
briefly.
Fill the membrane cap
with electrolyte, See
"Topping up reference
electrolyte", page 21
Avoid adding these
substances.
Change the water.
3
If necessary shorten
maintenance intervals.
inflow.
Avoid damaging the
membrane. Do not
knock the sensor
when the membrane
cap is screwed on.
Avoid incident flow
containing coarse
pieces or glass
splinters.
Avoid allowing
surfactants to affect
the membrane. After
cleaning the system,
thoroughly flush out all
detergents or other
disinfectants.
Check installation and
change if necessary.
Remove cleaning
agents and
disinfectants
completely after use.
32
10 Eliminating errors and faults
Error/fault Possible cause Remedy Preventive
measures
(5) The DPD and
sensor values match
and the trend of the
redox measurement is
correct, but the
setpoint value is not
maintained.
(6) Sensor value and
DPD value do not
match,
sensor values
fluctuate: too much /
not enough.
Incorrect control
parameters.
The amount of
disinfectant dosed per
unit of time is too high.
Concentration is
exceeded before the
process medium
reaches the sensor.
System circulation is
too slow.
System circulation is
too slow.
Optimize the control
parameters.
Reduce the amount
added per unit of time.
Reduce the
concentration of
disinfectant in the
solution added.
Improve mixing. Make structural
changes to ensure
more thorough mixing.
Improve mixing. Make structural
changes to ensure
more thorough mixing.
(7) Sensor is unusually
slow in responding
(8) Output signal of the
sensor is 0
Membrane partially
blocked by
contamination such as
lime or oil.
This interferes with the
disinfectant reaching
the sensor.
Sensor connected to
the transmitter/
controller with reverse
polarity.
Measuring lead
broken.
Sensor faulty. Send the sensor in to
Transmitter/controller
faulty
Replace membrane
cap.
Connect the sensor
correctly, See section
6 "Electrical
connection", page 17
Replace measuring
lead.
the manufacturer to
have it checked/
repaired.
Send the transmitter/
controller in to the
manufacturer to have it
checked/repaired.
Take steps to improve
the water quality.
33
JUMO GmbH & Co. KG JUMO Instrument Co. Ltd. JUMO Process Control, Inc.
Street address:
Moritz-Juchheim-Straße 1
36039 Fulda, Germany
Delivery address:
Mackenrodtstraße 14
36039 Fulda, Germany
Postal address:
36035 Fulda, Germany
Phone: +49 661 6003-0
Fax: +49 661 6003-607
E-mail: mail@jumo.net
Internet: www.jumo.net
JUMO House
Temple Bank, Riverway
Harlow - Essex CM20 2DY, UK
Phone: +44 1279 63 55 33
Fax: +44 1279 63 52 62
E-mail: sales@jumo.co.uk
Internet: www.jumo.co.uk
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Canastota, NY 13032, USA
Phone: 315-697-
1-
800-554-JUMO
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