Camlab CW/6230 User manual

Dissolved Oxygen Meter - Instruction Manual
Ref: CW/72.32.20
Camlab Water Model CW/6230
%
°C
%O
2
hPa mg/l
mmHg
SAL OK Cal hPa
MEAS
HOLD
°F
°C
MeasCal
Hold RclStore
On
Off Menu
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Table of Contents Page
1. Scope of delivery .............................................................. 4
2. System description ........................................................... 4
3. Connections ..................................................................... 6
4. Display ............................................................................. 6
5. Keypad ............................................................................ 8
6. Startup ............................................................................. 8
7. Measurement ................................................................. 10
8. Configuration of the unit ................................................. 11
8.1 Resolution of display for oxygen measurement ............... 11
8.2 Zero point temperature offset ......................................... 11
8.3 Salinity: salinity correction ............................................... 12
8.4 Display of sensor status ................................................. 12
8.5 Pressure Absolute, display of absolute pressure ............. 13
8.6 Selection of temperature unit°C /°F ............................... 13
8.7 Selection of unit for oxygen partial pressure .................... 13
8.8 „Power off“: automatic unit switch-off ............................. 13
9. Oxygen measurement .................................................... 14
9.1 Absolute pressure .......................................................... 14
9.2 Salinity correction ........................................................... 15
10. Calibration of oxygen measurement ................................ 15
10.1 Performing calibration ..................................................... 15
11. Oxygen sensor ............................................................... 16
11.1 Technical data ................................................................ 16
11.2 Operating notes ............................................................. 17
11.3 Design of the sensor ...................................................... 18
11.4 Care and maintenance ................................................... 19
12. Result memory ............................................................... 21
12.1 Storing results ................................................................ 21
12.2 Displaying stored results ................................................. 21
12.3 Deleting stored results .................................................... 21
13. Error messages and troubleshooting .............................. 22
14. Technical data ................................................................ 23
15. Accessories .................................................................... 26
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1. Scope of delivery
Standard:
• Camlab Water CW6230
• Measuring cell
• Batteries, 4*AA 1,5 V Cells
• Operating instructions
• Carrying strap
Set:
• Camlab Water CW6230
• Batteries, 4*AA 1,5 V Cells
• Measuring probe
• Carrying case
• Operating instructions
• Carrying strap
2. System description
The Camlab Water CW6230 is a sturdy, water-
tight handheld meter designed for daily measurements
in the area of field or laboratory analysis.
It is used to measure oxygen concentration in surface
waters and groundwater as well as for waste water
and service water analysis.
The system complies with the requirements in EN
60529 relating to protection class IP67 and water-
proof/dustproof properties.
The permanent protective plating on the unit serves
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not just as impact protection but also as a storage
compartment for the sensor and as an anti-slip device
when the meter is used in an upright position.
Microprocessor technology and 4*AA 1,5 V batteries
allow unit operation without battery change for 12,000
hours or more.
A "Low Bat” indicator in the display shows the user
when it is time to change the batteries.
The required temperature compensation for the sy-
stem is performed automatically following connection
of the temperature sensor (NTC, 10 kOhm) that is in-
tegrated as standard in the Tintometer oxygen sen-
sor.
The AUTO HOLD feature enables the user to identify
stable results and call them up on the display.
The standard MEAS measuring function is for conti-
nuous measurement of oxygen concentrations, parti-
al pressures or saturations.
The absolute atmospheric pressure is measured in the
unit and is automatically used, for among other things,
calculation of the oxygen partial pressure or calibrati-
on of the system.
The integrated automatic salinity correction feature is
based on the "International Oceanographic Tables" and
is user-selectable in the range from 0% to 70% via the
configuration function of the unit.
The system is calibrated using the oxygen in the air.
A sensor evaluation is automatically shown in the dis-
play (or can be called up via the menu) after each ca-
libration.
An internal memory for 20 results is integrated in the
unit as standard. The memory stores location, result
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and temperature.
The memory is called up via the display.
3. Connections
%
°C
mmHg hPa mg/l %O2
SAL OK CAL hPa
MEAS
HOLD °F
°C
Meas CAL
Hold KCl Store
On
Off Menu
123
456
789
%
°C
pH
RealmV
mV
ATCOCAL
MAX
MEAS
MIN
HOLD
°F
°C
MeasCAL
HoldKClStore
On
OffMenu
Oxygen sensor
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4. Display
Main Display: Result or user
prompt
[mmHg] Oxygen partial pressure
in mmHg
[hPa] Oxygen partial pressure
in hPa
[mg/l] Oxygen concentration
[%O2] Oxygen saturation
Secondary
display: Result - temperature
or user prompt
[%] Percent (sensor evaluation)
[°C/°F] Temperature unit
[∆
!
]Warning index - battery
[SAL] Salinity correction on/off
[OK] Measuring signal stable
[CAL] Auto. oxygen calibration
[hPa] Absolute air pressure
%
°C
%O
2
hPa mg/l
mmHG
SAL OK CAL hPa
MEAS
HOLD
°F
°C
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5. Keypad
[Meas] Continuous measurement -
standard
[Hold] Auto-Hold: Automatic
retaining of stable result
[On/Off] On / Off
[▲] [▼]Display change: partial pressure,
concentration or saturation. Leaf
through menu or display
[Rcl] Display of stored results
[Cal] Calibration mode
[Store] Storage of current result or acceptance of
unit configuration
[Menu] Unit configuration
6. Startup
The unit is supplied with integrated batteries as stan-
dard and is therefore ready for immediate use. You
have to unscrew the unit to insert or change the batte-
ries.
Remove
6 screws
4 x AA 1,5 V
Don`t
touch
Display
Meas Cal
Hold Rcl Store
On
Off Menu
Rcl
Meas Cal
Menu
Hold Store
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When inserting the batteries, ensure correct polarity!
Screw the unit back together carefully without exer-
ting too much pressure on the gasket seal.
If the [∆
!
]symbol appears together with "bAt” in the
lower section of the display, this means that the batte-
ries are nearly empty and need replacing.
However, the unit will continue to function for a certain
period of time.
If "bAt" appears in the upper section of the display,
this means that the batteries are completely empty.
Only use the matching Camlab oxygen sensors!
Other sensors may cause serious damage to the me-
ter and the sensor.
The sensor or temperature sensor must be plugged in
before the unit is switched on.
Switch the unit on via the [On/Off] key.
The system must be calibrated when the system is
first used.
Following measurement, please switch the unit off
using the [On/Off] key.
See the enclosed Operating Instructions for more de-
tailed information on storage and care of the sensors.
On
Off
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7. Measurement
Measuring mode MEAS
After the unit is switched on, it is automatically in the
standard measuring mode (MEAS).
You can switch to the standard MEAS measuring mode
by pressing the [Meas] key.
The display shows the current, possibly still fluctua-
ting result and [Meas].
If the result is stable, the [ok] arrow appears in the
display.
Measuring mode HOLD
Pressing the [Hold] key takes you into the AUTO HOLD
measuring mode.
In this mode, the recorded result is checked by the
system in line with the predefined stability criteria until
these criteria are met.
The display shows Auto/HOLD in alternating mode to-
gether with the result.
Once a stable reproducible value is present, the result
is shown permanently in the display ("frozen”).
The display also shows HOLD and the temperature.
If you press the [Hold] key again, the measuring cycle
starts again and runs until the stability criteria are met.
Meas
Hold
Meas
Hold
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8. Configuration of the unit
To configure the unit, press the [Menu] key.
The first menu item appears.
If you press the [Menu] key again, the display jumps to
the next menu item.
You can set the various parameters using the
[▲] [▼].
keys.
Press the [Store] key to store and conclude configura-
tion.
The unit then switches back to measuring mode.
You can terminate the configuration process by pres-
sing the [Meas] or [Hold] key.
Settings made up to this point are not stored.
The unit retains the previous settings.
8.1 Resolution: resolution of display
for oxygen measurement
Hi: high resolution, restricted measuring ranges
Lo: low resolution, maximum measuring ranges
Auto: automatic, maximum measuring ranges
Hold
Meas
+
Hold
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8.3 Salinity: salinity correction
0...70,0 ‰: Selection of salinity correction
off: Salinity correction inactive
8.4 Display of sensor status
Indication of the sensor status that is computed inter-
nally during every calibration depending on the sen-
sor used.
100% The electrode is in excellent condition.
30...90% The condition of the electrode is ade-
quate.
<30% The electrode is old from use or soiled.
If there is no improvement after you have cleaned and
recalibrated the sensor (see operating instructions for
electrode), you need to replace the sensor.
%
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8.5 Pressure Absolute, display of ab-
solute pressure
Display of the absolute atmospheric pressure in hPa.
8.6 Selection of
temperature unit °C /°F
°CAll temperature values in degrees Celsius
°FAll temperature values in degrees Fahrenheit
(°C = 0.556*°F-17.8 or °F = 1.8*°C+32)
8.7 Selection of unit for oxygen partial
pressure
hPa: Oxygen partial pressure in hPascal
mmHg: Oxygen partial pressure in mm
mercury column
8.8 „Power off“: automatic unit
switch-off
If no key is pressed during the switch-off delay period,
the unit switches off automatically after the selected
time has run down.
The desired delay time is entered in minutes.
If P.oFF = oFF, automatic unit switch-off is inactive.
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9. Oxygen measurement
Please note the following when measuring dissolved
oxygen:
The sensor should be calibrated after the unit is swit-
ched on.
The sensor and the liquid to be measured must have
the same temperature (leave until the temperatures
match if necessary)
Measurements are only sufficiently accurate if perfor-
med with a minimum flow rate of approx. 30 cm/sec;
in other words, the liquid must be constantly stirred or
a suitable stirring mechanisms must be used.
Remove the protective cap prior to measurement.
The oxygen partial pressure, the oxygen concentrati-
on [mg/l] and the oxygen saturation [%] are calculated
on the basis of the sensor signal and the temperature.
The measurement is based on steam-saturated air in
accordance with DIN38408-C22.
9.1 Absolute pressure
The absolute atmospheric pressure is measured in the
unit.
The measured air pressure primarily affects saturation
measurement [%] but also plays a major role during
automatic oxygen calibration.
During depth measurements, there are different pres-
sure conditions at the sensor and it is necessary to
correct the oxygen saturation [%].
The results for oxygen concentration [mg/l] and oxy-
gen partial pressure are not affected by this.
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9.2 Salinity correction
The higher the salinity, the lower the solubility of oxy-
gen in water; in other words, fewer mg of oxygen are
dissolved per litre of water at the same oxygen partial
pressure.
It is therefore necessary to first enter the salinity of the
medium in order to determine the oxygen concentra-
tion.
The salinity correction feature is adjusted for aqueous
media whose chemical composition corresponds to
that of seawater.
Correction is based on the "International Oceanogra-
phic Tables” (IOT).
10. Calibration of oxygen measurement
The sensor data of oxygen sensors are affected by
ageing and manufacturing tolerances that result in fluc-
tuations. You should therefore calibrate the unit with
the sensor on a regular basis.
The sensor is automatically adjusted to the oxygen
content of the air (20.95%; 1-point calibration).
We recommend calibration prior to each series of
measurement.
10.1 Performing calibration
Remove the protective cap from the sensor prior to
calibration.
Pat the diaphragm dry using a soft cloth.
During calibration, the sensor must be surrounded by
air with a relative humidity of approx. 100%.
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Starting calibration: -Press [Cal] key.
‘CAL’ appears in the display.
As soon as the results for oxygen, temperature and air
pressure are constant, calibration is terminated auto-
matically.
The sensor status (‘ELEC’, valuation in 10% steps) is
then briefly displayed.
Depending on the temperature, a correctly calibrated
sensor shows a result of 102..114% (oxygen saturati-
on).
If error messages occur during calibration, please see
the troubleshooting tips.
If calibration is not completed after you have waited a
lengthy period of time, at least one of the three measu-
ring signals (oxygen partial pressure, temperature or
air pressure) is not stable.
In this event, you should check the measuring setup.
11. Oxygen sensor
11.1 Technical data:
Measuring range of the unit:
Oxygen partial pressure: 0 ... 1200 hPa O
2
Temperature: -5.0 ... 50.0°C
Sensor: Galvanic, active dia-
phragm-covered sen
sor, with integrated NTC
resistor
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Response time: 95% in 10 sec., tem-
perature-dependent
Operating life: 3 years or more, care-
dependent
Operating pressure: max. 3 bar.
Installation diameter: Ø 12.0±0.2 mm (fits a
1/2 " screw connection,
for example)
Overall length: approx. 220 mm (incl.
anti-kink protection)
Installation length: approx. 110 mm
Weight: approx. 180 g
Operating temperature: 0 to +40°C
Storage temperature: 0 to +60°C
The galvanic self-polarising sensor with silver cathode
and lead anode with potassium hydroxide as an elec-
trolyte, is an active system.
The lead anode, the silver cathode and the electrolyte
are used up during operation.
The sensor is affected by ageing over time.
Continuous maintenance of the sensor is therefore
necessary.
11.2 Operating notes
a.) The oxygen sensor must always be kept moist to
prevent the membrane from drying out. To this end,
you should place the sensor in deionised water in the
supplied storage cap.
If the diaphragm has dried out, the sensor needs to
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be watered for approx. 2 hours prior to measurement.
It then needs to be recalibrated.
b.) The sensors may only be used with the correspon-
ding units. The use of the sensors in combination with
unsuitable units can destroy the unit and the sensors!
c.) Unit and sensor must be handled with care and
used in accordance with the technical data outlined
above. Always protect the connector and connection
socket against soiling and dirt.
d.) Do not insert the connector at an angle. If the con-
nector is inserted properly, you should be able to press
it in without using force.
When disconnecting the sensor, do not pull it by the
cable but always by the connector sleeve.
e.) Remove the sensor storage cap before performing
measurements.
11.3 Design of the sensor
The housing of the sensor probe is made of PVC. With
the exception of the sensor shaft, all parts must be
serviced regularly and replaced if necessary.
Storage cap: The storage cap is used to moisten the
membrane. This increases the service life of the sen-
sor. The storage cap contains deionised water.
Membrane cap: the diaphragm head is covered with
a Teflon membrane.
The diaphragm cap is filled with KOH electrolyte and
screwed onto the sensor shaft in such a way that the-
re are no air bubbles.
Sensor
shaft
O-Ring-
seal
membrane
cap
Refill
opening
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Damaged membrane or air bubbles in the membrane
cap cause incorrect results.
The membrane cap is listed in the spare parts list.
Refill opening: if the sensor is used at excessive tem-
peratures or stored outside the storage bottle for
lengthy periods of time, this will result in electrolyte
evaporation losses.
If necessary, you should therefore unscrew the dia-
membrane head, remove the sealing screw, and fill up
the electrolyte using a syringe.
Then screw the sealing screw back in place.
11.4 Care and maintenance
If the sensor is not needed, it should be stored either
in the storage cap (filled with water) or directly in a
container full of deionised water.
If a bacterial, fungal or algae coating has formed on
the membrane, you should wipe off the coating using
a soft paper cloth prior to measurement.
If it is no longer possible to calibrate the sensor or if
the membrane is damaged, the sensor needs servicing.
Air bubbles in the membrane cap can affect measure-
ments. Please remove carefully.
! Exercise caution during maintenance work – the elec-
trolyte is caustic !
Wear disposable gloves when servicing the sensor and
wash your hands thoroughly with water afterwards.
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Servicing the sensor:
Unscrew the membrane head and wipe off the elec-
trolyte solution carefully using a paper cloth.
Do not allow the electrolyte to come into contact with
your hands. If it does come into contact with your skin,
rinse the affected area thoroughly in water.
To clean the silver cathode, sand lightly using sandpa-
per (240 grit). Do not sand the silver cathode to a
smooth finish. It needs to be rough so that the electro-
lyte is distributed evenly. Carefully remove the sanding
dust after sanding.
Unscrew the refill screw and fill up carefully with elec-
trolyte until it just overflows (disposable syringe). Screw
the refill screw back in place.
Fill new membrane cap with electrolyte, avoiding air
bubbles.
Screw the sensor vertically into the cap from above.
When you insert the sensor, the electrolyte is displa-
ced from the membrane head and overflows.
Remove excess electrolyte using a paper cloth.
Turn the sensor upside down and check for air bubbles.
If there are no air bubbles, servicing is complete.
If air bubbles are still present, please remove carefully.
If the O-ring seal is damaged it needs replacing.
Important note: leave the sensor to settle for at least 1
hour before performing recalibration.
If it is still not possible to calibrate the sensor despite
servicing, the sensor needs to be checked at the fac-
tory and replaced if necessary.
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