Page 1
Instruction Manual
Portamess 911 pH
ProMinent Dosiertechnik GmbH • D-69123 Heidelberg • Germany
Page 2
ProMinent Dosiertechnik GmbH
Im Schuhmachergewann 5–11
D-69123 Heidelberg
Postfach 10 17 60
D-69007 Heidelberg
T elephone: +49 (06221) 842-0
Fax: +49 (06221) 842-419
info@prominent.de
www.prominent.de
We reserve the right to make technical changes.
TA–193.102–PME01 250401
Software version: 3.x
Page 3
Safety Precautions
Be sure to read and observe the following requirements!
Whenever it is likely that the protection has been impaired, the meter shall
be made inoperative and secured against unintended operation.
The protection is likely to be impaired if, for example:
❏ the meter shows visible damage
❏ the meter fails to perform the intended measurements
❏ after prolonged storage at temperatures above 70 °C
❏ after severe transport stresses
Before recommissioning the meter, a professional routine test according to
EN 61 010-1 shall be performed. This test should be carried out at our factory.
Information III
Page 4
Information on this Instruction Manual
cal
Note
Warning
Italics are used for texts which appear in the Portamess
911 pH display.
Bold print is used to represent keys,
e.g. cal.
Display examples
or
keys whose functions are explained are frequently shown
in the left-hand column.
Notes provide important information that should be strictly
followed when handling the meter.
Warning means that the instructions given must always be
followed for your own safety. Failure to follow these instructions may result in injuries.
Information IV
Page 5
Contents
Safety Precautions III. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Information on this Instruction Manual IV. . . . . . . . . . . . . . . . . . . . . . . . . .
1 The Model 911 pH 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Package Contents 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Short Description of Meter 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 Operation 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Meter Design 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Display 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Keypad 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sensoface
Connection and Start-up 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Configuration 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Calibration 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Measurement 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3 Troubleshooting and Maintenance 17. . . . . . . . . . . . . . . . . . . . . . . . . . .
Sensoface Electrode Monitoring 17. . . . . . . . . . . . . . . . . . . . . . . . . .
Error Messages 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Appendix 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accessories Available 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications Portamess
4 General Information on Measurement 27. . . . . . . . . . . . . . . . . . . . . . . .
Notes on pH Measurement 27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Glossary 33. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Index 35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrode Monitoring 5. . . . . . . . . . . . . . . . . . . . . . . . . .
911 pH 25. . . . . . . . . . . . . . . . . . . . . . . . .
Contents V
Page 6
Contents VI
Page 7
1 The Model 911 pH
Package Contents
Please check the completeness of the package after unpacking.
The package should include:
❏ Portamess
❏ PHEKT–013–F pH electrode
❏ Quality buffer solutions pH
pH 4.0 50 ml
pH 7.0 50 ml
❏ Carrying strap
❏ This instruction manual
❏ Short instructions in German, English and French
❏ Field case
Short Description of Meter
❏ The Portamess 911 pH is used for pH and temperature
measurement in industry, environment, food processing
and waste-water treatment.
❏ The meter meets the European EMC regulations
(89-336-EEC) and the recommendations of NAMUR
NE 21.
❏ The meter is IP 66 protected to EN 60529 (jet water
from all directions).
❏ Temperature compensation is automatic with a Pt 1000
temperature probe, an NTC 30 kW (automatic recognition during power-on) or through manual temperature
input.
❏ Calibration can be carried out with buffer solutions from
various, preselectable buffer sets. The buffer is then
automatically recognized by the Calimatic
911 pH (ready for operation)
.
The Model 911 pH 1
Page 8
❏ You can also calibrate manually by entering individual
buffer values.
❏ The Sensoface
electrode monitoring system checks
the connected electrode and provides information on its
state.
❏ Only three alkaline AA batteries are required for uninter-
rupted operation for approx. 2,000 hours.
The Model 911 pH 2
Page 9
2 Operation
Meter Design
meas cal
Y
B
on/off
Portamess
5
1 Electrode connection
3 Reference electrode
2, 3 T emperature probe connection
4 Unused
5 Electrode container
1234
Operation 3
Page 10
Display
Battery
empty
Rinse
electrode
Stir buffer
solution
Electrode
response
time
Press cal
key
Wait
Senso-
face
Zero/
slope
Keypad
on/off
Note
meas
cal
Operation 4
Measurement
symbol
Temperature
detection
using Pt1000/
NTC
Error
message
Secondary
display
Main
display
Pressing on/off switches the meter on or off. When the
meter is switched off, one of the Sensoface
Manual
temperature
detection
status indicators is visible in the display. After power-on, the meter automatically performs a self test and checks which temperature probe is connected. After that it automatically goes to
pH measuring mode.
The meter can also be switched on with meas. However,
in this case only a short test is performed and the temperature probe is not determined. The meter assumes that the
last temperature probe determined is used.
Pressing meas selects the desired measured variable (pH
or mV) for the main display.
Pressing cal starts calibration. With calibration the meter
is adjusted to the electrode. Y ou can choose between one,
two or three-point calibration either using Calimatic
matic buffer recognition or with manual buffer entry.
auto-
Page 11
Y B
For manual temperature specification (no temperature
probe connected), the temperature is set using
Y and B.
During buffer selection, you can select the buffer set using
Y and B.
+
cal
Note
Sensoface
Pressing cal + on/off when the meter is switched off,
on/off
activates buffer selection.
When pressing two keys at the same time, make sure that
the key shown at the left is pressed first.
Electrode Monitoring
The Sensoface automatic electrode monitoring system
provides information on the electrode state. Zero point,
slope, response time, impedance and drying out are evaluated.
For more detailed information on the displayed electrode
state and the individual evaluations of the parameters,
please see chapter “Troubleshooting and Maintenance”
(Pg. 17).
Connection and Start-up
Electrode
connection
Commercially available electrodes with a nominal electrode zero point of pH 7 and the following plugs can be
connected:
–Coaxial standard plug to DIN 19 262
and/or
–4 mm banana plug.
Operation 5
Page 12
Connection
assignment
Note
Connection Socket. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Combination electrode 1. . . . . . . . . . . . . . . . . . . . . . . .
Single measuring electrode 1. . . . . . . . . . . . . . . . . . . .
Single reference electrode 3. . . . . . . . . . . . . . . . . . . . .
Integrated temperature probe of
combination electrodes 2. . . . . . . . . . . . . . . . . . . . . . .
Separate temperature probe 2, 3. . . . . . . . . . . . . . . . .
Unused 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1234
If no temperature probe has been connected, the meter
operates with the manually set temperature and man appears in the display.
Prior to first measurement, the buffer set to be used must
be selected and the meter calibrated.
Start-up
Note
on/off
Operation 6
With the meter switched-off, one of the Sensoface
status
indicators is always visible.
Even with the meter switched off, the calibration data re-
main permanently stored.
Pressing on/off switches the meter into measuring mode.
After power-on, the meter determines the connected temperature probe and performs a self test:
❏ Simultaneous appearance of all display segments, sym-
bols and Sensoface
indicators
❏ Display of Model No. 911
❏ Display of software version
❏ Display of selected buffer set
Page 13
Note
The temperature probe is only recognized during the
power-on procedure after pressing on/off.
Note
The meter can also be switched on with meas. However,
in this case only a short test is performed and the temperature probe is not determined. The meter assumes that the
last temperature probe determined is used.
Operation 7
Page 14
Configuration
Note
+
on/off
cal
Y B
cal
meas
Automatic
or manual
calibration
Operation 8
If you calibrate using the ProMinent buffer set, generally
you do not have to change the configuration.
The following basic settings can be changed in the configuration:
❏ Automatic calibration (Calimatic
)
on or off (manual), buffer set for automatic
calibration
❏ Three-point calibration on or off
To activate the configuration hold down cal with the meter
switched off and then press on/off.
The menu items of the configuration menu are worked
through in sequence.
To change the setting of the respective menu item, press
Y or B.
Pressing cal switches to the next menu item and stores
the displayed settings.
Pressing meas exits the configuration menu at any time.
The value last displayed and possibly hanged will then not
be saved.
Y ou can select whether you wish to calibrate with the Cali-
matic
automatic buffer recognition system or with manual
entry of the individual buffer values.
When calibrating with Calimatic
automatic buffer recognition (AutCal on), you only have to enter the buffer set used
once in the configuration menu. The buffer values are
stored at the correct temperature. During calibration the
meter then automatically recognizes the buffer used (factory setting: automatic calibration on, ProMinent buffer
solution).
Page 15
Buffer
selection
Select the buffer set with the buffers used in the buffer set
selection. V arious calibration buffer sets are stored in the
Portamess
911 pH.
The following buffer sets are permanently stored in the
meter:
Note
BUFFER –00–
Knick technical buffers
pH 2.00 4.01 7.00 9.21
BUFFER –01– Mettler T oledo technical buf fers
(former Ingold)
pH 2.00 4.01 7.00 9.21
BUFFER –02– ProMinent
pH 2.00 4.00 7.00 9.00 12.00
BUFFER –03– DIN 19 267
pH 1.09 4.65 6.79 9.23 12.75
BUFFER –04– Ciba (94)
pH 2.06 4.00 7.00 10.00
BUFFER –05– NIST
pH 1.68 4.00 7.00 10.01 12.46
BUFFER –06– DIN 19 266 and NIST (NBS)
pH 1.679 4.006 6.865 9.180
BUFFER –07– HACH
pH 4.00 7.00 10.18
The meter can only operate properly if the buffer solutions
used correspond to the selected, activated buffer set.
Other buffer solutions, even those with the same nominal
values, demonstrate a different temperature behavior . This
leads to measurement errors.
For manual buffer specification (AutCal off), the pH value
of the buffer solution must be entered for the correct temperature.
This allows calibration using any other buffer solution.
Operation 9
Page 16
Three-point
calibration
on/off
Y ou can choose whether you want to perform three-point
calibration in addition to one- or two-point calibration.
With three-point calibration turned on (3P-Cal on), you can
calibrate with a third buffer solution after two-point calibration has been completed. The sequence of the buffer solutions is unimportant. With three-point calibration zero point
and slope are calculated using a mean straight line (to
DIN 19268).
With three-point calibration turned off (3P-Cal off), only
one- or two-point calibration is possible (default setting:
(3P-Cal off).
Operation 10
Page 17
Calibration
By calibration the pH meter is adjusted to zero point and
slope of the electrode used.
Note
Calimatic
automatic
calibration
Note
cal
For calibrations and measurements at temperatures other
than room temperature, the following must always be observed:
Not only the buffer solution and the measured medium, but
also the electrode must be brought to the corresponding
temperature before the calibration is started or the measured value is read.
For calibration using Calimatic
tion, you only have to enter the buffer set used once in the
configuration menu. With the patented Calimatic
automatic buffer recogni-
system,
the meter automatically recognizes the buffer solutions,
calculates the electrode zero point and slope and carries
out the corresponding adjustment.
The meter can only operate properly when the buffer solutions used correspond with the buffer set selected during
buffer selection.
Other buffer solutions, even with the same nominal values,
may demonstrate different temperature behavior , which
leads to measurement errors.
Pressing cal activates calibration.
Calibration can be exited again by pressing meas. If exited prior to entry of the first calibration point, zero and
slope of the last calibration are displayed for a moment.
Immerse electrode and temperature probe in the first buffer
solution. Either buffer solution can be used first.
Press cal again to start calibration. If you do not want to
calibrate, press meas to cancel the process.
Operation 11
Page 18
During buffer recognition the lower line indicates the temperature. The hour glass flashes.
The nominal value of the recognized buffer solution is displayed for approx. 5 s. Electrode and temperature probe
must remain in the first buffer solution until the display
prompts for the second buffer.
Note
Note
Operation 12
The response times of electrode and temperature probe
are considerably reduced if you first move the electrode in
the buffer solution and then keep it still to read the values.
This provides stable values more quickly.
The electrode stability is checked and the measured mV
value is displayed. Stability check can be overridden with
cal. However, this reduces calibration accuracy.
Calibration with the first buffer is complete. Remove electrode and temperature probe from the first buffer solution
and rinse off both thoroughly .
❏ If you want to perform a one-point calibration, press
meas to terminate the calibration now. The meter then
shows the newly determined zero point in the main display and the old slope in the lower display and returns to
pH measuring mode.
❏ For two-point calibration, immerse the electrode and
temperature probe in the second buffer solution. Continue the calibration with cal. The calibration process
runs again as for the first buffer.
Only with three-point calibration turned on (3P-CAL On,
see Pg. 10) the calibration menu offers the possibility to
evaluate a third buffer solution after two-point calibration
has been completed.
With three-point calibration turned off (3P-CAL OFF ,
see Pg. 10) the calibration procedure is automatically ended at this point.
Page 19
With three-point calibration turned on (3P-CAL On), you
can now evaluate a third buffer solution.
❏ For two-point calibration, press meas to terminate the
calibration. The meter then shows the newly determined
zero point in the main display and the new slope in the
lower display and returns to pH measuring mode.
❏ If you want to perform a three-point calibration, immerse
the electrode and temperature probe in the third buffer
solution. Continue the calibration with cal. The calibration process runs again as for the previous buffers and
is automatically terminated. Zero and slope are calculated using a mean straight line (to DIN 19268).
At the end of the calibration the zero point and slope
(based on 25 °C) of the electrode are displayed. Then the
meter switches back to measuring mode.
Manual
calibration
cal
Note
For calibration with manual buffers, you must first disable
the Calimatic. Then, you must enter the pH of the buffer
solution used for the correct temperature.
This allows calibration with any buffer solution.
Pressing cal activates calibration.
Calibration can be cancelled by pressing meas. In that
case, zero and slope of the last calibration are displayed
for a moment.
Enter the temperature-corrected pH of your buffer solution
using Y and B. Press cal to start the calibration.
The buffer value set is stored so that you do not have to
enter it for the next calibration (which must be performed at
the same temperature).
If the temperature has changed, the pH value must be
adjusted before proceeding.
The response times of electrode and temperature probe
are considerably reduced if you first move the electrode in
the buffer solution and then keep it still to read the values.
This provides stable values more quickly.
Operation 13
Page 20
Note
Operation 14
The electrode stability is checked and the measured mV
value displayed. Stability check can be overridden with
cal. However, this reduces calibration accuracy.
Calibration with the first buffer is complete. Remove electrode and temperature probe from the first buffer solution
and rinse off both thoroughly .
❏ If you want to perform a one-point calibration, press
meas to terminate the calibration now. The meter then
shows the newly determined zero point in the main display and the old slope in the lower display and returns to
pH measuring mode.
❏ For two-point calibration, immerse the electrode and
temperature probe in the second buffer solution. Enter
the pH value of the second buffer solution. Continue the
calibration with cal. The calibration process runs again
as for the first buffer.
Only with three-point calibration turned on (3P-CAL On,
see Pg. 10) the calibration menu offers the possibility to
evaluate a third buffer solution after two-point calibration
has been completed.
With three-point calibration turned off (3P-CAL OFF ,
see Pg. 10) the calibration procedure is automatically ended at this point.
❏ For two-point calibration, press meas to terminate the
calibration. The meter then shows the newly determined
zero point in the main display and the new slope in the
lower display and returns to pH measuring mode.
❏ If you want to perform a three-point calibration, immerse
the electrode and temperature probe in the third buffer
solution. Enter the pH value of the third buffer solution.
Continue the calibration with cal. The calibration process runs again as for the previous buffers and is automatically terminated. Zero and slope are calculated using a mean straight line (to DIN 19268).
Page 21
At the end of the calibration the zero point and slope
(based on 25 °C) of the electrode are displayed. Then the
meter switches back to measuring mode.
Converting slope
% mV/pH % mV/pH
78
79
80
81
82
83
84
85
86
87
88
89
90
46.2
46.8
47.4
48.0
48.5
49.1
49.7
50.3
50.9
51.5
52.1
52.7
53.3
% –> mV/pH
91
92
93
94
95
96
97
98
99
100
101
102
103
53.9
54.5
55.1
55.6
56.2
56.8
57.4
58.0
58.6
59.2
59.8
60.4
61.0
Operation 15
Page 22
Measurement
Measuring
mode
meas
Note
Manual
temperature
Pressing meas accesses the measuring mode from all
functions. In measuring mode the main display indicates
the measured variable and the secondary display the temperature. The measured variable is selected with meas.
Y ou can choose between the following variables:
❏ pH
❏ Electrode potential [mV]
The response times of electrode and temperature probe
are considerably reduced if you first move the electrode in
the buffer solution and then keep it still to read the values.
This provides stable values more quickly.
The man indicator signals that no temperature probe is
connected. The meter operates with the manual temperature. The manual temperature can be edited using Y and
B.
Operation 16
Page 23
3 Troubleshooting and Maintenance
SensofaceElectrode Monitoring
The automatic Sensoface electrode monitoring system
provides information on the electrode state. It evaluates
zero point, slope and response time of the electrode.
Note
The deterioration of the electrode condition is signified by
or of the Sensoface indicator (”smiley”).
This devaluation is permanent. An improvement
only take place after a calibration.
This Sensoface
trode response time, i.e. on the amount of time an electrode requires to supply a stable measured value. The
value is determined during calibration.
Due to wear, aging and as the result of incorrect handling,
e.g. drying out, the swelling layer of the glass membrane of
an electrode may recede. This leads to a longer response
time and the electrode becomes sluggish.
The electrode response is slow. You should consider
maintaining or replacing it. It may be possible to
achieve an improvement by cleaning or, for an electrode returned to duty after dry storage, by rehydrating.
The electrode response is very slow. Correct measurement is no longer ensured. The electrode should be
maintained. If appropriate maintenance fails to remedy
the situation, the electrode should be replaced.
display provides information on the elec-
Maintenance and Troubleshooting 17
can
Page 24
SLOPE
ZERO
This Sensoface
display provides information on the elec-
trode zero point and the slope.
Zero and slope of the electrode are still okay, however
the electrode should be maintained or replaced soon.
Zero and/or slope of the electrode have reached values which no longer ensure proper calibration. It is
advisable to replace the electrode.
Note
The zero and slope values are determined during calibration. Accurate information is required for proper calibration.
For this reason, always use fresh buffer solutions.
Maintenance and Troubleshooting 18
Page 25
Error Messages
Sensor
problems
ERROR 1
ERROR 2
ERROR 3
If there are problems with a sensor, an error message appears and the measured-value display flashes.
Problem with the electrode
Possible causes:
❏ Electrode defective
❏ Too little electrolyte in the electrode
❏ Electrode not connected
❏ Break in electrode cable
❏ Wrong electrode connected
❏ Measured pH less than -2 or greater than +16
Problem with the electrode
Possible causes:
❏ Electrode defective
❏ Electrode not connected
❏ Break in electrode cable
❏ Measured electrode potential less than -1,300 mV or
greater than +1,300 mV
Problem with temperature probe
Possible causes:
❏ Temperature probe defective
❏ Short circuit in temperature probe
❏ Wrong temperature probe connected
❏ Measured temperature less than -20 °C or greater than
+120 °C
Maintenance and Troubleshooting 19
Page 26
Note
Calibration
error
messages
ERROR 4
ERROR 5
Maintenance and Troubleshooting 20
When changing the temperature probe (also for electrodes
with integrated temperature probe), note that the temperature probe type (Pt 1000/NTC 30 kW) is only recognized
when the meter is switched on with on/off.
If errors occur during calibration, or if the determined electrode data are outside the valid range, an error message
appears (ERROR 4 ... ERROR 11).
The electrode zero point determined during calibration is
outside the permissible range. The zero point is less than
pH 6 or greater than pH 8.
This message appears in measuring mode following a
calibration. It can only be remedied by recalibration with
fresh buffer solutions.
Possible causes:
❏ Electrode ”worn out“
❏ Buffer solutions unusable or falsified
❏ Buffer does not belong to configured buffer set
❏ Temperature probe not immersed in buffer solution (for
automatic temperature compensation)
❏ Wrong buffer temperature set (for manual temperature
specification)
The electrode slope determined during calibration lies outside the permissible range. The slope is less than 78 % or
greater than 103 %. This message appears in measuring
mode following a calibration. It can only be remedied by
recalibration with fresh buffer solutions.
Possible causes:
❏ Electrode ”worn out“
❏ Buffer solutions unusable or falsified
❏ Buffer does not belong to configured buffer set
❏ Temperature probe not immersed in buffer solution (for
automatic temperature compensation)
Page 27
ERROR 8
ERROR 9
ERROR 10
❏ Wrong buffer temperature set (for manual temperature
specification)
The meter has recognized two identical buffer solutions.
This message is only displayed during calibration.
Calibration must be repeated with fresh buffer solutions.
Possible causes:
❏ Same or similar buffer solution was used for both cal-
ibration steps
❏ Buffer solutions unusable or falsified
❏ Electrode defective
❏ Electrode not connected
❏ Break or short circuit in electrode cable
The meter cannot recognize the buffer solution used. This
message is only displayed during calibration. Calibration
must be repeated with fresh buffer solutions.
Possible causes:
❏ Buffer does not belong to configured buffer set
❏ Electrode defective
❏ Electrode not connected
❏ Break in electrode cable
❏ Wrong buffer temperature set (for manual temperature
specification)
During manual calibration, the buffer solutions were not
used in the specified order. Calibration must be repeated.
ERROR 11
Calibration was cancelled after approx. 2 minutes because
the electrode drift was too large.
This message is only displayed during calibration. Calibration must be repeated with fresh buffer solutions.
Maintenance and Troubleshooting 21
Page 28
ERROR 18
ERROR 19
Note
Possible causes:
❏ Electrode defective or dirty
❏ No electrolyte in the electrode
❏ Electrode cable insufficiently shielded or defective
❏ Strong electric fields influencing the measurement
❏ Major temperature fluctuation of the buffer solution
❏ No buffer solution or extremely diluted
If the meter determines an error during the self-test, this
error message appears: Configuration data defective
Possible causes:
❏ Configuration or calibration data are defective. Com-
pletely reconfigure and recalibrate the meter.
Error in the factory settings or system memory.
”FAIL“ appears in the display.
Possible causes:
❏ EPROM or RAM defective
❏ Error in meter factory settings
This error message should normally not occur as the data
are protected from loss by multiple safety functions.
Should this error message nevertheless appear, no remedy is available. The meter must be repaired and recalibrated at the factory.
Maintenance and Troubleshooting 22
Page 29
Maintenance
Changing
batteries
Note
Warning
Cleaning the
meter
If the battery symbol appears in the display, the batteries
need replacement. However, you can still use the meter for
a few days. When the battery voltage decreases further,
the meter switches off.
❏ Close the meter protection cover and remove the elec-
trode container.
❏ Unscrew the four screws on the back of the meter and
remove the cover.
❏ Remove the old batteries from the battery holder.
❏ Insert the new batteries in the specified direction.
❏ Make sure the meter protection cover is in the notches
provided and the rubber seal is correctly seated, especially near the pH socket.
❏ Remount the cover and secure it with the screws. Be
sure to tighten the screws thoroughly.
❏ Remount the electrode container.
When changing the batteries, all calibration data are re-
tained. The meter switches to pH measurement.
If you want to store the meter for a longer time, the batteries must always be remove beforehand. Leaky batteries
may damage the meter.
To remove dust and dirt, the external surfaces of the meter
may be cleaned with water, and also with a mild household
cleaner if necessary.
Maintenance and Troubleshooting 23
Page 30
Appendix
Accessories Available
Sensors
Electrode container, 5 pieces (for leakproof storage of pH electrode)
Quality buffer solutions pH
pH 4.0 50 ml
pH 7.0 50 ml
pH 9.0 50 ml
KCl solution,3-molar 250 ml 791440
Cleaning solution
pepsin/hydrochloric acid 250 ml
PHEKT–013–F combination electrode
body: plastic, 110 mm
Ref. No.
1008716
506251
506253
506254
791443
1007774
Appendix 24
Page 31
Specifications Portamess 911 pH
Ranges pH: -2.00 to +16.00
Display LC display 35 x 67 mm, character height 15 mm
Measurement
Cycle
Measurement Error
(± 1 count)
Input DIN 19 262
Input Resistance
Input Current
(20 °C)
Electrode Stan-
dardization
Meter and Electrode Monitoring
T emperature Compensation
Data Retention configuration and calibration data, factory settings
Auto Switch-off after 1 hour
RFI Suppression to EN 50 081-1 and EN 50 081-2
Immunity to
Interference
Environmental
Temperature
Power Supply 3 alkaline AA cells
Operating Time approx. 2,000 h*
mV: -1,300 to +1,300
°C: -20.0 to +120.0
approx. 1 s
pH: < 0.01
mV: < 0.1 % of meas. value ± 0.3 mV
°C: < 0.3 K
> 1 x 1012 W
-12
< 1 x 10
Calimatic automatic calibration with automatic buf-
fer recognition (German patent 29 37 227)
manual electrode standardization
Sensoface: evaluates the calibration interval,
Meter self test: during power-on
Pt 1000 / NTC 30 kW
(automatic recognition during power-on) or manual
> 10 years
to EN 50 082-1, EN 50 082-2 and NAMUR NE 21
Operation: -10 to +55 °C
Transport and storage: -20 to +70 °C
A
zero point, electrode slope, response time and glass impedance
of the electrode, optical indication
good/average/poor
* Due to storage, the service life of the included battery may be shorter.
Appendix 25
Page 32
Enclosure
Dimensions 133 x 160 x 30 mm (w x h x d)
Weight approx. 560 g including batteries
Material: PA, IP 66 protected,
with integrated electrode container
Appendix 26
Page 33
4 General Information on Measurement
Note
The chapter “General Information on Measurement” provides a summary of the most important points to be observed during pH measurement. Y ou can skip this chapter
if you are sufficiently familiar with the practice of pH measurement.
Notes on pH Measurement
General
information
Calibration
and measurement
Two electrodes, a glass electrode and a reference electrode, are required for electrometric pH measurement.
They are usually offered combined in a glass or plastic
body as a so-called combination electrode.
During pH measurement, simultaneous temperature detection is required. For a correct pH value, you must always
specify the respective measurement temperature, e.g.
pH
= 7.15.
25°C
Using a temperature probe together with the electrode
allows to optimally use the advantages of the microprocessor controlled pH meter.
Combination electrodes with integrated temperature probe,
e.g. PHEKT–013–F combination electrode (order no.
1007774), are particularly advantageous.
The measuring characteristics of pH electrodes are different for each electrode, are variable and temperature-dependent. Therefore, the meter must be adjusted to the
respective current electrode characteristics. This process
is called calibration.
For calibration, you take measurements of buffer solutions.
These are solutions with exactly defined pH values. With
the Portamess
able, i.e. automatic calibration using Calimatic
al calibration.
911 pH two calibration modes are avail-
and manu-
Information on Measurement 27
Page 34
Calimatic
automatic
calibration
In the Portamess
911 pH the chart values of various
buffer sets are stored for the correct temperatures. Simply
select and enter the buffer set once when commissioning
the meter (see Pg. 9). Then the patented Calimatic
will
calibrate the meter at the press of a key.
Calibration is conducted with two different buffer solutions
from the preset buffer set. The sequence of buffers is irrelevant. The pH meter measures the electrode voltages and
the temperatures and compares them with the programmed pH temperature charts for the buffer solutions.
From the measured values the meter calculates the zero
point and slope of the electrode. This type of calibration
with two buffer solutions is a two-point calibration.
For one-point calibration, only one buffer solution is used
and the calibration process is discontinued after the first
calibration step. Only zero point is adjusted in the process.
The previous slope value is retained.
The Portamess
911 pH also allows to perform a threepoint calibration. Here, three buffer solutions are required.
Zero point and slope are calculated using a mean straight
line (to DIN 19268).
Note
Manual
calibration
The buffer solutions used for calibration must always correspond to the buffer set selected in the meter.
If you want to work with special buffer solutions not included in the stored buffer sets, select manual calibration
(see Pg. 13). Here, you enter your individual buffer value at
the correct temperature (pH at calibration temperature).
Values entered once remain stored. During the next calibration the meter will suggest these values. That means,
you do not have to enter the values once more provided
that the sequence of the last calibration is retained.
Note
Make sure that the buffer values are entered for the proper
temperature. Do not enter the nominal buffer value but
instead the pH of the buffer solution at the calibration temperature.
Information on Measurement 28
Page 35
Calibration
intervals
Observe
the following:
The calibration interval is highly dependent on the conditions under which measurements are taken. As a result, no
generally valid interval can be given here.
However, the calibration can be repeated frequently at the
beginning. If the calibration values (electrode zero and
slope) show only minor differences, the time between calibrations can be increased.
For measurements under constant conditions, weekly calibration may be sufficient. On the other hand, calibration
may be necessary prior to each measurement when measuring in media with large temperature or pH differences.
❏ For electrodes with liquid electrolyte, open the KCl filling
hole for calibration, measurement and cleaning.
❏ Immerse the electrode in the buffer solution ensuring
that the junction is completely immersed.
❏ Electrode response time is considerably reduced if you
first move the electrode in the buffer solution and then
keep it still to read the values.
❏ Always rinse the electrode with deionized water before
immersing it in the buffer solution.
❏ If you calibrate without a temperature probe, make sure
that the manually set temperature matches the actual
temperature of the buffer solutions and the substance to
be measured.
Information on Measurement 29
Page 36
Design of a combination electrode with liquid electrolyte
filling hole
reference electrolyte
junction
glass membrane
Buffer
solutions
Note
Note
Information on Measurement 30
Two buffer solutions are required for a two-point calibration. The pH values of the buffer solutions should differ by
at least two pH units and bracket the expected measured
value.
To ensure measurement accuracy, the buffer solutions
should be fresh.
❏ Never pour used buffer solution back into the storage
container. Never use used buf fer solution.
❏ Never immerse the electrode directly in the storage con-
tainer.
❏ Always keep the storage container closed. The carbon
dioxide from the air can lead to incorrect buffer solution
values.
The problems described above can be avoided by using
buffer bags (see Accessories Available on Pg. 24).
Page 37
Electrodes
Today combination electrodes are commonly used due to
the simpler handling involved.
When using combination electrodes, ensure a symmetric
design when interconnecting:
❏ The dissipation systems of glass and reference elec-
trodes have the same potential (e.g. both Ag/AgCl, KCl
3 mol/l, AgCl saturated or both “calomel“, KCl saturated).
❏ Only combine Thalamide glass electrodes with Thala-
mide reference electrodes.
The nominal zero point of commercially available electrodes is pH 7. For additional information, refer to the appropriate electrode instruction manual.
Electrode care
Proper cleaning and care increases electrode service life
and measurement accuracy. Therefore, you should observe the following points:
❏ When not in use, store electrodes in KCl solution (refer-
ence electrolyte). Never store them dry.
For a few hours the electrode can also remain in the
electrode container, without liquid.
❏ Soak dry electrodes in KCl solution for up to 12 hours
prior to initial use.
❏ For electrodes with liquid electrolyte, open the KCl filling
hole for calibration, measurement and cleaning.
❏ Make sure the electrolyte in the electrode is always at
least 2 cm (1 ”) higher than the medium to be measured.
Top up the KCl solution if necessary. Use the KCl solution specified by the manufacturer.
Grease and oil deposits on the electrode can be removed
with hot water and a household dishwashing liquid.
Protein contaminations can be removed by soaking the
electrode in a pepsin-hydrochloric acid solution (electrode
cleaner) for one hour.
Information on Measurement 31
Page 38
Temperature
compensation
❏ Do not rub the electrode dry with a cloth or fleece, as
this will cause electric charging which may later result in
incorrect measurements or even make them impossible.
The temperature compensation takes the temperature
dependency of the electrode slope into account. Reference
temperature for zero and slope of the meter is 25°C.
The pH of the medium to be measured is also temperature-dependent. This temperature dependence is unknown
and depends on the composition of the measured medium.
As a result, this temperature dependence cannot be compensated. Therefore, always indicate the measuring temperature together with the pH (observe when comparing
measured pH values!).
Note
In the case of a major temperature difference between the
calibration and measuring temperature, an additional temperature effect may affect the electrode performance.
These effects are not subject to any general rules (in contrast to the temperature dependence of the slope). To
achieve a particularly high degree of measurement accuracy, this error can be eliminated by calibrating at the measuring temperature (recommended by DIN 19268). The
temperature dependence of the calibration buffer pH values is automatically taken into consideration during calibration with Calimatic
Information on Measurement 32
.
Page 39
Glossary
Auto
switch-off
Buffer set
Buffer
solution
cal
Calibration
Calibration
buffer set
Calimatic
Combination
electrode
Electrode
slope
Electrode
zero point
To protect the batteries, the meter switches off automatically after one hour when not operated for a longer period.
Contains selected buffer solutions which can be used for
automatic calibration with the Calimatic
must be selected prior to initial calibration.
Solution with an exactly defined pH for calibrating a pH
measuring instrument.
Key for activating calibration.
Adjustment of the pH meter to the current electrode char-
acteristics. The zero point and slope are adjusted. A one-,
two-, or three-point calibration can be carried out. With
one-point calibration only the zero point is adjusted.
See buffer set.
Automatic buffer recognition. Before the first calibration,
the buffer set used must be activated once. The patented
Calimatic
tion used during calibration.
Combination of glass and reference electrode in one body.
Is indicated in % of the theoretical slope (59.2 mV/pH at
25 °C). The electrode slope is different for every electrode
and changes with age and wear.
The voltage which a pH electrode gives off at a pH of 7.
The electrode zero point is different for every electrode and
changes with age and wear.
then automatically recognizes the buffer solu-
. The buffer set
GLP
Good Laboratory Practice: Rules for conducting and documenting measurements in the laboratory.
Glossary 33
Page 40
meas
This key is used to return to measurement mode from all
other levels. In measuring mode it switches between mV
and pH.
NAMUR
One-point
calibration
pH electrode
system
Response
time
Sensoface
Slope
Three-point
calibration
Two-point
calibration
German committee for measurement and control standards in the chemical industry
Calibration with which only the electrode zero point is
taken into consideration. The previous slope value is retained. Only one buffer solution is required for a one-point
calibration.
A pH electrode system consists of glass and reference
electrodes. If they are combined in one body, they are referred to as a combination electrode.
Time from the start of a calibration step to the stabilization
of the electrode potential. This time is one of the criteria for
the Sensoface
Automatic electrode monitoring. The Sensoface
indicator.
indicators provide information on the status of the electrode and
the meter. Calibration interval, zero, slope and response
time of the electrode are evaluated.
See electrode slope.
Calibration in which the electrode zero and slope are taken
into consideration. Three buffer solutions are required for
three-point calibration.
Zero point and slope are calculated using a mean straight
line (to DIN 19268).
Calibration in which the electrode zero and slope are taken
into consideration. Two buffer solutions are required for
two-point calibration.
Zero point
Glossary 34
See electrode zero point
Page 41
Index
, 17
A
accessories available, 24
auto switch–off, definition, 33
automatic calibration, 28
B
battery replacement, 23
buffer set
definition, 33
selection, 9
buffer solution, 30
definition, 33
C
calibration, 11, 27
automatic, 11, 28
configuration, 8
buffer solution, 30
definition, 33
manual, 13, 28
configuration, 8
calibration buffer set, definition, 33
calibration intervals, 29
Calimatic, 11, 28
configuration, 8
definition, 33
cleaning, 23
combination electrode, definition,
33
configuration, 8
configuration menu, 8
connection, electrode, 5
connection assignment, 6
D
diagnostics, Sensoface, 17
display, 4
E
electrode monitoring, Sensoface,
17
electrode slope, description, 33
electrode zero point, definition, 33
electrodes, 31
care, 31
connection, 5
monitoring, 5
error messages, 19–22
G
glossary, 33
GLP, definition, 33
K
keypad, 4
M
maintenance, 23
manual calibration, 28
manual temperature, 16
measurement, 16
measurement, general, 27
Index 35
Page 42
measuring mode, 16
messages, Sensoface, 17
meter design, 3
mV measurement, 16
N
NAMUR, definition, 34
O
one–point calibration, 12, 14
definition, 34
P
package contents, 1
pH electrode system, definition,
34
pH measurement, 16
notes, 27
R
response time, definition, 34
S
safety precautions, III
Sensoface, 5, 17
definition, 34
diagnostic, 17
messages, 17
short description, 1
slope, definition, 34
smiley , 17
specifications, 25
start–up, 5
T
temperature compensation, 32
three–point calibration, 13, 14
definition, 34
on/off, 10
two–point calibration, 12, 14
definition, 34
Z
zero point, definition, 34
Index 36
Page 43
Page 44
Addresses and delivery information
from the manufacturer:
ProMinent Dosiertechnik GmbH
Im Schuhmachergewann 5–11
D-69123 Heidelberg
Postfach 10 17 60
D-69007 Heidelberg – Germany
Phone: +49 (06221) 842-0
Fax: +49 (06221) 842-419
info@prominent.de
www.prominent.de
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