APERA EC820 Precision Benchtop Conductivity Meter Instruction Manual
- June 3, 2024
- APERA
Table of Contents
EC820 Precision Benchtop Conductivity Meter
EC820 Precision Benchtop Conductivity Meter
Instruction Manual
PH820 Lab pH Meter EC820 Lab Conductivity Meter PC820 Lab pH/Conductivity
Meter
APERA INSTRUMENTS (Europe) GmbH
www.aperainst.de
– 1 –
Table of Contents 1. BRIEF INTRODUCTION …………………………………………………………………………………………- 4
–
1.1 Measuring Parameters……………………………………………………………………………………..- 4 1.2 Features and
Functions ……………………………………………………………………………………- 4 1.3 Features in pH Measurement
(Applicable Models: PH820, PC820) …………………………- 4 1.4 Features in Conductivity
Measurement (Applicable Models: EC820, PC820) ……………- 4 2. Configuration
………………………………………………………………………………………………………..- 5 3. TECHNICAL SPECIFICATIONS
………………………………………………………………………………- 6 4. INSTRUMENT DESCRIPTION
………………………………………………………………………………..- 7 4.1 LCD
Display……………………………………………………………………………………………………- 7 4.2 Keypad
………………………………………………………………………………………………………….- 8 4.3 Connectors
…………………………………………………………………………………………………….- 9 4.4 Display
Mode………………………………………………………………………………………………..- 10 4.5 Data Storage, Recall, and
Deletion …………………………………………………………………..- 10 5. pH Measurement
………………………………………………………………………………………………… – 11 5.1 Set up Flexible Electrode
Holder……………………………………………………………………… – 11 5.2 Equipped Electrode
………………………………………………………………………………………. – 11 5.3 Information regarding pH
Calibration ……………………………………………………………….. – 11 5.4 pH Calibration (Take 3-point
calibration as an example) ………………………………………- 13 5.5 Customized Calibration
(take 1.60 pH & 6.50 pH as example)………………………………- 14 5.6 Sample
Measurement…………………………………………………………………………………….- 15 5.7 Maintenance of the pH
Electrode ……………………………………………………………………..- 16 6. mV
Measurement…………………………………………………………………………………………………- 17 6.1 ORP measurement
………………………………………………………………………………………..- 17 6.2 Notes on ORP measurement
…………………………………………………………………………..- 17 7. Conductivity
Measurement…………………………………………………………………………………….- 18 7.1 Set up flexible Electrode
Holder (refer to 5.1) …………………………………………………….- 18 7.2 Information regarding the
Conductivity Electrode………………………………………………..- 18 7.3 Information regarding
Conductivity Calibration……………………………………………………- 18 7.4 Conductivity Calibration
(take 1413 S/cm as an example) ………………………………….- 20 7.5 TDS, Salinity,
Resistivity & Conductivity…………………………………………………………….- 21 7.6 Customized
Calibration (take 10.50S/cm as example) ……………………………………….- 22 7.7 Sample
test…………………………………………………………………………………………………..- 22 7.8 Maintenance of the
Conductivity Electrode ………………………………………………………..- 23 8. Parameter
Setting………………………………………………………………………………………………..- 24 –
– 2 –
8.1 Main Menu……………………………………………………………………………………………………- 24 8.2 Sub-Menu …………………………………………………………………………………………………….- 24 8.3 pH Setting Sub- Menu……………………………………………………………………………………..- 25 8.4 Conductivity Setting Sub- Menu………………………………………………………………………..- 26 8.5 Basic Parameter Setting Sub-Menu ………………………………………………………………….- 27 9. USB DATA COMMUNICATION ………………………………………………………………………………- 28 9.1 Software Interface………………………………………………………………………………………….- 28 9.2 Install the software…………………………………………………………………………………………- 29 9.3 Choose COM Port …………………………………………………………………………………………- 29 9.4 Run Software………………………………………………………………………………………………..- 29 10. Recommended pH Electrodes for Specific Applications…………………………………………..- 30 11. APPENDIX 1: TABLE OF PARAMETER SETTING ………………………………………………..- 31 12. APPENDIX 2: ICONS AND ABBREVIATION …………………………………………………………- 32 13. APPENDIX 3: TABLE OF SELF- DIAGNOSIS SYMBOL ………………………………………….- 33 14. WARRANTY…………………………………………………………………………………………………….- 33 –
Special Notes
Do NOT pull out the power plug until the meter is turned off.
Don’t pull out USB plug or press
button to turn off the meter directly when the
meter is connecting with PC. Please press “Exit” button first (in the PC interface) to
quit PC Link Software, then press
button to turn off the meter, and pull out
USB plug after that. There is a CR2032 3V lithium battery in the meter’s circuit board, see
the picture on the right. It’s power source for meter inner clock. When
the voltage is lower than 2.6V after long time use, a blue screen with
on display values and icons may appear when turn on the meter. At
that moment, please open the meter and replace a new CR2032 3V
lithium battery.
– 3 –
1. BRIEF INTRODUCTION
Thank you for purchasing EC820 Precision Benchtop Conductivity Meters. Before
using the product, please read this manual carefully to help you properly use
and maintain the product.
1.1 Measuring Parameters
Measuring Parameters
PH820
EC820
PC820
Instrument Level
0.001 level
0.5 level
pH:0.001 level, Conductivity.:0.5 level
pH/mV
Conductivity/TDS/Salinity/Resistivity
Temperature
1.2 Features and Functions The built-in microprocessor chip enables advanced
functions such as auto calibration, auto
temperature compensation, auto. electrode recognition, parameter setting,
self-diagnosis, calibration reminder, calibration time check, auto power-off,
low-battery reminder, etc. GLP data management, real-time clock display.
Manual or Auto timing data storage. USB data communication. The meter adopts
advanced digital processing technology, intelligently improves the response
time and accuracy of the measurements. Stable reading and auto lock display
mode are available for choice. Meets IP54 Waterproof and dustproof rating,
connectors of the meter protected by rubber cap, ensuring quality, reliability
and service life especially in tough environments.
1.3 Features in pH Measurement (Applicable Models: PH820, PC820) 1 to 5 points
auto calibration with calibration guide and auto-check function. Automatic
recognition of pH buffer solutions. Two series of standard solutions for
choice: USA
and NIST, and customized solution. Automatic display of pH electrode slope.
1.4 Features in Conductivity Measurement (Applicable Models: EC820, PC820) 1
to 4 points auto calibration with calibration guide and auto-check function.
Automatic recognition of pH buffer solutions, and customized solution. Single-
tap switch among conductivity, TDS, salinity, and resistivity.
– 4 –
2. Configuration
Content
1 PH820 Lab pH Meter
2 EC820 Lab Conductivity Meter
3 PC820 Lab pH/Conductivity Meter
4 LabSen 211 Lab pH Electrode
5 2401T-F Conductivity Electrode (ATCk=1.0)
6 MP500 temperature electrode
7
pH Standard Buffer (4.00 pH,7.00 pH,10.01pH/50mL)
8
Conductivity Standard Solution (84S,1413S,12.88mS/50mL)
9 3M KCL Solution (50ml)
10 Pipette
11 9V Power Adapter
12 Flexible Electrode Holder
13 PC-Link Software Disk
14 USB Cable
15 Instruction Manual
16 Quick Manual
Quantity PH820 EC820 PC820
1
1
1
1
1
1
1 for each
1 for each
1
1
1
1
1
1
1
1
– 5 –
3. TECHNICAL SPECIFICATIONS
Measuring Range Resolution
pH
Accuracy
Temperature Compensation
Range
Measuring Range
mV
Resolution
Technical Parameters (-2.000 ~ 19.999 pH 0.1/0.01/0.001 pH ±0.002 pH ±1 digit
(0 ~ 100°C) Automatic or Manual
±1999.9mV 0.1mV
Accuracy
±0.03% FS ±1 digit
Conductivity: (0~2000) mS/cm, including 6 ranges: (0.00~19.99) S/cm; (20.0~199.9) S/cm (200~1999) S/cm; (2.00~19.99) mS/cm (20.0~199.9) mS/cm; (200~2000) mS/cm
Measuring Range
TDS: (0 ~ 100)g/L, including 5 ranges: (0.00~9.99) mg/L; (10.0~99.9) mg/L (100~999) mg/L; (1.00~9.99) g/L (10.0~100)g/L
Salinity: (0~100) ppt, including 2 ranges: (0 ~ 9.99) ppt; (10.0 ~100) ppt,
Cond.
Resolution
Temp.
Accuracy
Temperature Compensation
Range Electrode Constant
Measuring Range
Resolution
Resistivity: (0~100) M·cm, including 6 ranges: (0 .0~ 99.9)·cm; (100~ 999)·cm;
(1.00~ 9.99)K·cm; (10.0~ 99.9)K·cm; (100~ 999)K·cm; (1.0~ 100)M·cm,
Conductivity: 0.01/0.1/1S/cm; 0.01/0.1/1mS/cm TDS: 0.01/0.1/1mg/L; 0.01/0.1g/L
Salinity: 0.01/0.1/1 ppt; 0.01/0.1 ppt. Resistivity: 0.1/1·cm; 0.01/0.1/1
K·cm;
0.1M·cm.
±0.5% FS ±1 digit
(0 ~ 50°C) Automatic or Manual
0.01 / 0.1 / 1 / 10 cm-1
-10 to 110°C
0.1°C
Models PH820 PC820
EC820 PC820
PH820 EC820 PC820
– 6 –
Other
Accuracy Data Storage Storage Content Data Output
IP Rating Calibration
±0.4°C ±1 digit PH820/EC820: 500 Groups; PC820: 1000 Groups Numberings, Date,
Time, Measurements, Unit, Temperature
USB IP54 Waterproof and Dustproof pH1~5 pointsConductivity1~4 points
4. INSTRUMENT DESCRIPTION 4.1 LCD Display
Figure-1
—- Measuring parameters —- Measuring value —- USB data communication. The
meter is connected to your PC when this icon is
displayed. —- Timing storage —- Date, time, and reminder icons —- “Date” and
“Time” —- Measuring unit —- Measuring unit in calibration —- Calibration
value, numberings of data storage, and reminder icons —- Temperature unit
– 7 –
—- Data storage and display icon M+– Data storage; RM– Recall saved data
—- Temperature and reminder icons —- ATC–Auto Temperature Compensation; MTC–
Manual Temperature Compensation —- Completed calibration icons —- Auto-Lock
reading mode —- Stable reading icon
4.2 Keypad
Figure-2 Short Press — <1.5 sLong Press — >1.5 s
Table-1 Keypad Operation and Functions
Keypad Operation
Functions
Short Press
Power on/off
Choose measuring mode:
Short pH Meter
Press pH/Conductivity Meter
Long Press
Enter parameter setting
Short Press
Enter calibration mode
Short In pH mode: choose resolution: 0.1 pH0.01pH0.001pH
Press In conductivity mode, choose measuring mode:
Short Press
Short Press
Short Press
In calibration mode: press to calibrate In parameter setting mode: press to confirm choice Cancel any operation, the meter goes back to measurement mode Save measuring data
– 8 –
Long Press
Short Press or
Long Press
Recall saved measuring data
In manual temperature compensation (MTC) mode: Short press to adjust
temperature, long press to adjust swiftly
In parameter setting mode: press to change the numbering of parameters in main
menu and sub-menu.
In sub-menu, press to change parameters and settings. In recall mode (RM),
short press to change numberings, long press to
change swiftly.
4.3 Connectors
Table-2 Connectors of Different Models
Connectors
Model
PH820 pH Meter
EC820 Conductivity Meter
PC820 pH/Conductivity Meter
Icon REF pH/mV TEMP COND USB DC9V
Table3 Connector Name and Type Connector Name
Connector Type
Reference Electrode Plug
2 Banana Plug
pH Electrode and ORP Electrode Plug Temperature Plug (sharing for pH and
conductivity) Conductivity Plug
USB Communication Plug
DC9V Power Plug
BNC Connector RCA Connector BNC Connector Standard Four Core Connector 2.5 Power Plug
– 9 –
4.4 Display Mode
4.4.1 Stable Reading Display Mode When the measuring value is stable, the screen displays
as shown
in figure-3. If does not appear or is flashing, that means the measuring value has not been stable. Users should wait for the smiley face to appear and stay before recording the readings or conducting calibrations.
4.4.2 Auto-Lock Display Mode In parameter setting P5.4, select “On” to turn on the auto-lock mode,
in which the measuring reading will be automatically locked after
icon has been stable for 10 seconds, and the HOLD icon will come
up as shown in figure-4. At this time, short press
to cancel the hold.
4.5 Data Storage, Recall, and Deletion 4.5.1 Manual Data Storage
When reading is stable, short press
, the screen will display M+ Icon
along with the storage numbering, and the data will be saved, as shown
in figure-5. For the storage capacity for each model, please refer to section 3. 4.5.2 Automatic Timing Data Storage
In parameter setting P5.1, set up the time for timing measurements (e.g.
3 minutes). will be displayed, meaning the meter is ready to enter the
auto timing storage mode. Short press , the icon will start flashing,
and the 1st group of data will be stored. 3 minutes later, the 2nd one will be stored. Figure-6 shows that 8 groups of data have been automatically
stored. Short press
again, the icon will stop flashing. The meter
stops the auto timing storage. When in auto timing storage, manual storage is disabled. In parameter setting P5.1, set the time to 0 to exit auto timing storage.
4.5.3 Recall the Stored Data In measurement mode, long press
(>1.5 s), the meter will recall
the Measured value that was lastly saved, as shown in figure-7, displaying
RM Icon and the numbering. Press
or
to recall other stored
data. Long press
or
to change numberings swiftly. Press
to return to measurement mode.
– 10 –
Figure-3 Figure-4 Figure-5 Figure-6 Figure-7
4.5.4 Clear Stored Data In parameter P5.3, select Yes to clear all the stored data. For details, please refer to section 7.5
5. pH Measurement
5.1 Set up Flexible Electrode Holder The flexible electrode holder is composed of a base and an electrode holder. Place the electrode holder right above the metal stick on the base through the hole underneath; push down; and adjust the nut on electrode holder to finish installation.
5.2 Equipped Electrode The instrument is equipped with a LabSen 211 Combination Glass pH Electrode and MP500 Temperature Electrode. Please install both pH and temperature electrode on the electrode holder before using. Please find technical parameter and instructions of LabSen 211 pH electrode from its user manual.
5.3 Information regarding pH Calibration
5.3.1 Standard Buffer Solutions The instrument adopts two series of standard buffer solutions: USA and NIST as shown in Table-4. Users can select which one to use in P1.1 (refer to section 7.3)
Table-4 pH Standard Buffer Series
Calibration Icons
pH Standard Buffer Series
USA Series
NIST Series
5 Points Calibration
3 Points Calibration
1.679 pH 4.005 pH 7.000 pH 10.012 pH
1.679 pH 4.006 pH 6.865 pH 9.180 pH
12.454 pH
12.454 pH
5.3.2 Two pH Calibration Modes The instrument adopts two different pH
calibration mode: 3 points of calibration (3P) and 5 points of calibration
(5P). Users can select which to use in P1.4 (refer to section 7.3) (a) 3-point
calibration mode 3-point calibration is most often used. In the 3-point
calibration mode, the 1st point must be 7.00 pH (or 6.86 if using NIST). Then
choose other calibration solutions to conduct 2nd and 3rd points (see
– 11 –
Table-5 for details). In the process of calibration, the meter will display
the electrode’s slope in acid and alkaline ranges.
Table-5 3-point Calibration Mode
USA series
NIST series
Calibration icon
When to adopt
1-Point Calibration
2-Point Calibration
3-Point Calibration
7.000 pH
7.000 pH and 4.005 pH
7.000 pH and 10.012 pH
7.000 pH, 4.005 and 10.012 pH
6.865 pH
6.865 pH and 4.006 pH
6.865 pH and 9.180 pH
6.865 pH, 4.006, and 9.180 pH
Accuracy ±0.1 pH
Measuring range: 7.000 pH
Measuring range: 7.000 pH
Wide measuring range
(b) 5-point calibration mode In 5-point calibration mode, user can choose 1~5 points to calibration, in any calibration solution and any order. Such as choosing 1.679pH and 4.005pH for measuring strong acid solution and choosing 10.012pH and 12.454pH for measuring strong base solution. The electrode’s slope will not be displayed during the calibration.
5.3.3 How often to calibrate The frequency that you need to calibrate your
meter depends on the tested samples, performance of electrodes, and the
requirement of the accuracy. For High-Accuracy measurements ( ±0.03pH), the
meter should be calibrated before test every time; For ordinary-accuracy
Measurements (±0.1pH), once calibrated, the meter can be used for about a week
or longer. In the following cases, the meter must be re-calibrated: a) The
electrode hasn’t been used for a long time or the electrode is brand new. b)
After measuring strong acid (pH<2) or strong base (pH>12) solutions. c) After
measuring fluoride-containing solution and strong organic solution d) There is
a big difference between the temperature of the test sample and the
temperature of the
buffer solution that is used in the last calibration.
5.3.4 Calibration Reminder Function
Preset the interval between calibrations (starting from the time when
you set it), and then the meter will remind you to calibrate at the end of
that interval. For details, please see P1.2 (Section 7.3). When the (refer
to section 7.3), preset time is reached, Er6 icon will be displayed at the
Figure-8
lower right corner of the LCD (as showed in Figure-8). At the time, the
meter can still be operated. It is just reminding you to do calibration in order to ensure the accuracy.
– 12 –
After calibration, the Er6 icon will disappear; To make it disappear, users can also choose “No” in P1.2 in parameter setting.
5.3.5 Check calibration date In this mode, users can see the date and time of last calibration to help determine if there is a need to re-calibrate. For details, please see parameter setting P1.3 (Section 7.3)
5.4 pH Calibration (Take 3-point calibration as an example)
5.4.1 Press
to enter calibration mode. CAL1 icon will flash in the
upper right corner of the LCD. 7.00 pH will flash in the lower right corner of the LCD, reminding you to use pH 7.00 buffer solution to conduct 1st point of calibration.
5.4.2 Use distilled water to rinse off electrode and then dry it. Dip it into pH 7.00 buffer solution, stir gently and let it stand still and wait for the reading to become stable. In the lower right corner of LCD, the process of auto recognizing the buffer solution will be displayed. Pressing before the buffer is recognized will generate Er2 (please refer to table 6).
5.4.3 When the meter locks 7.00 pH,
displays on LCD. Press
key to calibrate the meter. End icon appears after calibration is done. The 1st point calibration is finished. In the meanwhile, CAL2 will flash at the upper right corner, and 4.00 pH & 10.01 pH will flash alternately at the bottom right, indicating using pH 4.00 or pH 10.01 buffer solution to make the 2nd point calibration.
5.4.4 Take out pH electrode, rinse it in distilled water, dry it, and dip it into pH 4.00 buffer solution. Stir the solution gently and let stand still in the buffer solution until a stable reading is reached. The meter’s display will show the recognition process of calibration buffer solution at the
lower right of LCD. When the meter recognizes 4.00 pH, displays
on LCD. Press
key to calibrate the meter. End icon and
Figure-9
electrode slope of acidity range display after calibration is done. In the meanwhile, CAL3 will flash at the upper right corner of the LCD, and 10.01 pH will flash at the lower right, indicating using pH10.01
– 13 –
buffer solution to make the 3rd point calibration.
5.4.5 Take out pH electrode, rinse it in distilled water, dry it, and dip it into pH 10.01 buffer solution. Stir the solution gently and let it stand still in the buffer solution until a stable reading is reached. The meter’s display will show recognition process of calibration buffer solution at the bottom right of LCD. When the meter
recognizes 10.01 pH, displays on LCD. Press
key to calibrate the meter. End icon and
electrode slope of alkalinity range display after calibration is done. The meter returns to the
measurement mode, displays stable measuring value and calibration guide icons
.
Please see Figure-9 for the above calibration process.
5.4.6 Operation of 5 points of calibration is the same as above, but user can determine calibration solution and calibration order. Electrode’s slope will not show during the calibration. In 3 points and
5 points of calibration, press
key to return to measurement mode. Users can proceed 1~3
points of calibration in 3P mode, and 1~5 points of calibration in 5P mode, LCD will show relatively calibration icons.
5.5 Customized Calibration (take 1.60 pH & 6.50 pH as example)
5.5.1 Choose CUS (customized calibration) in parameter setting P1.1, the meter enters customize
calibration mode. Press
key, CAL1 will flash on at the upper right corner of the LCD, indicating
start of the 1st point calibration.
5.5.2 Use distilled water to rinse off electrode and then dry it. Dip it into 1.60 pH buffer solution, stir gently and let it stand still and wait for the reading to become stable, displays on LCD. Press
key, the reading flashes. Press
or
to adjust reading number to 1.60, then press
key to finish the calibration. CAL2 will flashes at the upper right corner of LCD, indicating start of 2nd point calibration.
5.5.3 Use distilled water to rinse off electrode and then dry it. Dip it into 6.50 pH buffer solution, stir gently and let it stand still and wait for the reading to become stable, displays on LCD. Press
key, the reading flashes. Press
or
to adjust reading number to 6.50, then press
key to finish the calibration and back to measurement mode. CUS will flashes at the upper right corner of LCD, but the completed calibration icons stop showing at the bottom left corner of LCD.
5.5.4 Special Notes
– 14 –
(a) The instrument can operate 1~2 points of customize calibration. Press
after finishing the
1st point calibration, the instrument will return to measurement mode. This is 1 point customize calibration. (b) If the temperature probe is not connected during calibration and measuring, which is MTC.
Temperature value will flash after pressing
key. Press
or
to input the right
temperature. Press
key once more, temperature value will flash.
(c) The pH of “customize calibration” is the measurement in certain temperature. The instrument must calibrate or measure in the same temperature, otherwise it will be inaccurate. The instrument does not recognize customize calibration solutions.
5.6 Sample Measurement 5.6.1 Rinse the pH electrode in distilled water or purified water, dry it, and dip it into sample solution. Stir the solution gently and let it stand still in the sample solution until icon appears and stays on LCD, get the pH reading, which is pH value of sample solution, please refer to Figure-10 for calibration and measurement process of the pH meter.
Press
to turn
on the meter.
Press
key to
enter the calibration
mode.
Submerge the electrode in pH7.00 solution, press key when icon appears.
Submerge the electrode in pH4.00 solution, press key when icon appears.
After the 1st point
calibration is done,
press
key to
enter the
measurement mode.
1 st point calibration
After the 2nd point
calibration is done,
press
key to
enter the
measurement mode.
2nd point calibration
Sample Test
Submerge the electrode in pH10.01 solution, press key when icon appears.
After the 3rd point calibration is done, the meter enters the measurement mode automatically.
3 r d point calibration
Figure-10
5.6.2 Self-Diagnosis Information Among the calibration and measurement procedure, the meter has self-diagnosis function, showing Er1~Er6 icon, reminding related information. Please refer to table-6.
– 15 –
Display Icons
Table 6 Self-diagnosis information
Contents
Wrong pH buffer solution or the buffer solution out of range.
Checking
1.Check whether pH buffer solution is correct. 2.Check whether the meter
connects the electrode
properly. 3.Check whether the electrode is damaged.
Press
when measuring value is not Press
stable during calibration.
stays.
key when
icon appears and
During calibration, the measuring value being unstable for over 3 minutes
1.Check whether there are bubbles in glass bulb.
2.Replace with a new pH electrode.
pH electrode zero electric potential out of range<-60mV or >60mV
pH electrode slope out of range (<85% or >110%)
1.Check whether there are bubbles in glass bulb. 2.Check whether pH buffer solution is correct. 3.Replace with new pH electrode.
Enter in pre-set due calibration to remind calibration
Press
key to perform calibration or
cancel due calibration setup in parameter P1.2.
5.6.3 According to the pH isothermal measurement principle, the closer the test sample’s temperature is to the calibration solution’s, the higher the accuracy of the measurement. So this principle is recommended to follow when conducting tests.
5.6.4 The instrument has a function to return to factory default setting, which can be set up in P1.4 (refer to section 7.3). Returning to factory default setting is to restore the meter to theoretical value (zero potential pH is 7.00, slope is 100%), and set all the parameters to default settings (see appendix 1). When the meter’s calibration or measurement is performing abnormally, users can use this function to let the meter return to factory default mode, and then conduct calibration and test again. Please note that this function is irreversible once used.
5.7 Maintenance of the pH Electrode 5.7.1 Cleaning of pH electrode Rinse the
pH electrode in purified water before and after measurement and then dry it.
After measuring vicious sample, the electrode needs to be cleaned many times
to remove the sample attached to glass membrane, or clean with proper solution
and then rinse in the purified water.
5.7.2 Renew the glass bulb Electrodes that have been used over a long period
of time will become aged. Submerge the electrode in 0.1mol/L hydrochloric acid
for 24 hours, then wash the electrode in purified water, then submerge
– 16 –
it in KCL soaking solution for 24 hours. For serious passivation, submerge the bulb in 4% HF (hydrofluoric acid) for 3-5 seconds, and wash it in purified water, then submerge it in the soaking solution for 24 hours to renew it.
5.7.3 Clean contaminated glass bulb and junction (please refer to Table-7) Table-7 Clean contaminated glass bulb and junction
Contamination
Cleaning Solutions
Inorganic metal oxide
Dilute acid less than 1mol/L
Organic lipid
Dilute detergent (weak alkaline)
Resin macromolecule
Dilute alcohol, acetone, ether
Proteinic haematocyte sediment
Acidic enzymatic solution (saccharated yeast tablets)
Paints
Dilute bleacher, peroxide
6. mV Measurement
6.1 ORP measurement
Press
to open, and press
to switch the meter to
mode. mV mode is a mode for
ORP and Ion electrode measurement. Connect ORP electrode and dip it in sample solution, stir the solution briefly and allow it to stay in the solution until icon appears and get the reading.
ORP means Oxidation Reduction Potential. The unit is mV. Connect Ion electrode and reference electrode to measure Ion electric potential.
6.2 Notes on ORP measurement 6.2.1 ORP measurement does not require calibration. When the user is not sure about ORP electrode quality or measuring value, use ORP standard solution to test mV value and see whether ORP electrode or meter works properly. Table-8 is the data of standard ORP solution for 222 mV.
Table-8 ORP Standard Buffer Solution222mV±15mV25°C
°C
10
15
20
25
30
35
38
40
mV
242
235
227
222
215
209
205
201
6.2.2 Clean and activate ORP electrode After the electrode has been used over a long period of time, the platinum surface will get polluted which causes inaccurate measurement and slow response. Please refer to the following methods to clean and activate ORP electrode:
– 17 –
(a) For inorganic pollutant, submerge the electrode in 0.1mol/L dilute
hydrochloric acid for 30 minutes, then wash it in purified water, then
submerge it in the soaking solution for 6 hours.
(b) For organic or lipid pollutant, clean the platinum surface with detergent,
then wash it in purified water, then submerge it in the soaking solution for 6
hours.
(c) For heavily polluted platinum surface on which there is oxidation film,
polish the platinum surface with toothpaste, then wash it in purified water,
then submerge it in the soaking solution for 6 hours.
7. Conductivity Measurement
7.1 Set up flexible Electrode Holder (refer to 5.1) 7.2 Information regarding
the Conductivity Electrode 7.2.1 Conductivity electrode EC820 and PC820 are
equipped with model 2401T-F plastic conductivity electrode with constant K=1.0
and built-in temperature sensor, can realize automatic temperature
compensation. When submerge the conductivity electrode in solution, stir the
solution briefly to eliminate the air bubbles and improve response and
stability.
7.2.2 Conductivity electrode constant The meter matches conductivity
electrodes of three constants: K=0.1, K=1.0 and K=10.0. Please refer to
table-9 for measuring range. Set constant in parameter setting P2.1 and refer
to clause 8.4
Table9 Electrode constant and measuring range
Range
20 S/cm
1.0 S/cm to 100 mS/cm
100mS/cm
Conductivity electrode constant
Standard solution Electrode’s model
K=0.1 84 S/cm DJST-0.1-F
84 S/cm
K=1.0
K=10
1413 S/cm 12.88 mS/cm 2401T-F
111.8 mS/cm 2310T-F
Note: When testing ultra-purified water with conductivity less than 1.0 S/cm, a flow test should be
conducted in a flow cell.
7.3 Information regarding Conductivity Calibration 7.3.1 Conductivity Standard Calibration Solutions The meter uses conductivity standard solution of 84 S/cm, 1413 S/cm, 12.88 mS/cm and 111.8 mS/cm. The meter can recognize the standard solution automatically, and perform 1~4 points of calibration. The calibration indication icons correspond to the four standard values as shown in Table
– 18 –
Table-10 Conductivity Calibration Solutions
Calibration Icons
Calibration Solutions
84 S/cm
1413 S/cm
12.88 mS/cm
111.8 mS/cm
7.3.2 How often to calibrate (a) The meter has been calibrated before leaving the factory and can generally be used right out of the box. (b) Normally perform calibration once per month. (c) For high accuracy measurements or large temperature deviation from the reference temperature (25°C), perform calibration once per week. (d) Use conductivity standard solution to check whether there is error. Perform calibration if error is large. (e) For new electrode or the meter has been set to factory default, perform 3-point or 4-point calibration. For general use, choose standard solutions that are closer to the sample solution to perform 1-point or 2-point calibration.
7.3.3 Single point and multi-point calibration If 1-point calibration is conducted after 3-point or 4-point calibration being done, the previous calibration values in the same range will be replaced. In the meanwhile, the meter will display the 1-point calibration’s icon, and the other calibration icons will be removed, but the chip will still store the data from the last calibration. When conducting multi-point calibration, users should follow the sequence from low conductivity to high in case the high concentration solution contaminating the low ones.
7.3.4 Reference Temperature The factory default setting for reference temperature is 25. The reference temperature can be set from 15 to 30. Users can set it up in parameter setting P2.4 (see Section 7.4 for details).
7.3.5 Temperature compensation coefficient The temperature compensation coefficient of the meter setting is 2.0%/°C. However, the conductivity temperature coefficient is different from solutions and concentration. Please refer to Table 11 and the data collected during testing. Do the setting in P2.5. (see section 7.4 for more).
– 19 –
Note: When the coefficient for the temperature compensation is set to 0.00 (no compensation), the measurement value will be based on the current temperature.
Table-11 Temperature compensation coefficient of special solutions
Solution
Temperature compensation coefficient
NaCl solution
2.12%/°C
5% NaOH solution
1.72%/°C
Dilute ammonia solution
1.88%/°C
10% hydrochloric acid solution
1.32%/°C
5% sulfuric acid solution
0.96%/°C
7.3.6 Precaution for calibration solution’s contamination Conductivity standard solution has no buffer. Please avoid being contaminated during usage. Before submerging the electrode in standard solution, please wash the electrode and allow it to dry, especially for standard solution of low concentration (84S/cm). The contaminated standard solution will affect accuracy.
7.3.7 Calibration Reminder Setup Preset the interval between calibrations (starting from the time when you set it), and then the meter will remind you to calibrate at the end of that interval. For details, please see P2.3 (Section 7.4). When the preset time is reached, Er6 icon will be displayed at the lower right corner of the LCD (as showed in Figure-11). At the time, the meter can still be operated. It is just reminding you to do calibration in order to ensure the accuracy. After calibration, the Er6 icon will disappear; To make it disappear, users can also choose “No” in P2.3 in parameter setting.
Figure-11
7.3.8 Check calibration date In this mode, users can see the date and time of last calibration to help determine if there is a need to re-calibrate. For details, please see parameter setting P2.4 (Section 7.4)
7.4 Conductivity Calibration (take 1413 S/cm as an example) 7.4.1 Rinse the
electrode in purified water, allow it to dry, wash with a little of standard
solution and submerge it in 1413S/cm standard solution. Stir briefly and allow
it to stay in the solution until a stable reading is reached.
– 20 –
7.4.2 Press
key to enter the calibration mode. The meter’s
display will show blinkingCAL at the top right, and scanning and locking process of calibration solution at the bottom right. Er2 icon will
appear if press
before value is locked. See table-6
7.4.3 When the meter locks 1413 S, stable icon will display on
LCD. Press
key to complete calibration. End will appear and the
meter will return to measuring mode and is displayed on bottom
left of the LCD screen. See figure-12.
7.4.4 Press
key before confirmation to exit calibration mode
(calibration will not be completed).
7.4.5 For multi-point calibrations, please repeat the steps in 6.4.1 to 6.4.3 until all calibrations are finished. The meter can be calibrated in the same calibration solution repeatedly until the reading is stable and repeatable.
7.5 TDS, Salinity, Resistivity & Conductivity
7.5.1 TDS and conductivity is linear related. The conversion factor is
0.40-1.00. Adjust the factor from parameter P2.7. The factory default setting is 0.71 and please refer to section 7.4. Salinity and resistivity are
Figure-12
all proportional to conductivity. The calculating formula is preset in the meter. So the meter only
needs to be calibrated in Conductivity mode, then after calibration of conductivity, the meter can
switch from conductivity to TDS, salinity, or resistivity.
7.5.2 Adjust TDS conversion factor in parameter setting P2.7 according to the
data collected during testing and experience. Table 12 lists some commonly
used Conductivity and TDS conversion factors. This is for your reference only.
Table12 Conductivity and TDS conversion factors
Conductivity of solution
TDS conversion factor
0~100 S/cm
0.60
100~1000 S/cm
0.71
1~10 mS/cm
0.81
10~100 mS/cm
0.94
– 21 –
7.6 Customized Calibration (take 10.50S/cm as example)
7.6.1 Choose CUS (customize calibration) in parameter setting P2.1, the meter enters customize
calibration mode. Press
key, CAL will flash on at the upper right corner of the LCD, indicating
start of the customize calibration.
7.6.2 Use distilled water to rinse off electrode and then dry it. Dip it into 10.50 S/cm buffer solution,
stir gently and let it stand still and wait for the reading to become stable,
displays on LCD.
7.6.3 Press
key, the reading flashes. Press
or
to adjust reading number to 1050
Then press
key, the decimal point flashes, press
key to set the decimal point to 10.50;
press
key, the unit flashes, press
key to set the unit to S/cm, the whole setting
procedure ends.
7.6.4 Press
key to calibrate, after calibration the meter back to measurement mode. In
customize calibration mode, CUS shows at the upper right corner of LCD, but the completed calibration icons stop showing at the bottom left corner.
7.6.5 Special Notes
(a) The customize calibration is 1-point calibration. The Conductivity of “customize calibration” is the
measurement in certain temperature. The instrument must calibrate or measure in the same
temperature, otherwise it will be inaccurate. The instrument does not recognize customize calibration
solutions.
(b) If the temperature probe is not connected during calibration and measuring, which is MTC. Please
press
or
to input the right temperature.
7.7 Sample test 7.7.1 Rinse conductivity electrode in distilled or purified water, dry it, and submerge it in the sample solution. Stir the solution briefly and allow it to stay in the sample solution until a stable reading is reached and icon appears on LCD, then get the reading value, which is the conductivity value of the solution.
7.7.2 Press
key to switch to TDS, Salinity, and Resistivity.
7.7.3 During the process of calibration and measurement, the meter has self- diagnosis functions, icons Er1~Er3 and Er6, indicating the relative information as below:
– 22 –
Display Icons
Table-13 Self-diagnosis information of conductivity measurement mode
Contents
Checking
Wrong conductivity calibration solution or the meter recognition of calibration solution out of range.
1.Check whether conductivity calibration solution is correct.
2.Check whether the meter connects the electrode well.
3. Check whether the electrode is damaged.
Press
key when measuring
Press
value is not stable during calibration.
key after icon appears.
During calibration, the measuring value being unstable for over 3 minutes.
1. Shake the electrode to eliminate bubbles in electrode head.
2. Replace with new conductivity electrode.
Enters pre-set due calibration to remind Press
key to perform calibration or
re-calibration
cancel due calibration setup in parameter P2.2.
7.7.4 Factory default setting For factory default setting, please refer to
parameter setting P2.8 (Section 7.4). With this function, all calibration data
is deleted and the meter restores to the theory value. Some functions restore
to the original value (refer to appendix -1). When calibration or measurement
fails, please restore the meter to factory default setting and then perform
re-calibration or measurement. Please note once set the factory default, all
the data deleted will be irretrievable.
7.8 Maintenance of the Conductivity Electrode 7.8.1 Always keep the
conductivity electrode clean. Before taking a measurement, rinse the electrode
in purified water. It is recommended to rinse it again in the sample solution.
When submerge the electrode in solution, stir the solution briefly to
eliminate air bubbles and allow it to make the measurement fast and stable.
7.8.2 Keeping the conductivity sensor in wet condition helps the electrode’s
quick reaction. Electrode may react slowly if kept dry for long time. Submerge
it in 12.88mS standard solution for 5 to 10 minutes or in tap water for 1 to 2
hours to renew it. Use distilled water to clean electrode after use.
7.8.3 The sensing rod of Model 2401T-F conductivity electrode is coated with
platinum black to minimize electrode polarization and expand measuring range.
The platinum black coating adopts our special processing technology, which
improves the electrode performance and the firmness of the coating. If the
platinum black electrode is stained, gently clean the electrode with a soft
brush in warm water containing detergent or alcohol.
– 23 –
8. Parameter Setting
8.1 Main Menu In the measurement mode, press
key to enter in P1.0. The meter has three main menus.
Press
or
to switch main menu: P1.0P2.0P5.0. Please refer to Figure – 14.
P1.0: pH parameter setting menu; P2.0: Conductivity parameter setting menu, P5.0: Basic parameter setting menu.
8.2 Sub-Menu
8.2.1 In P1.0, press
to enter the submenu P1.1 for pH setting, press
or
to
change submenu: P1.1P1.2 … P1.5. See 7.3 for details.
8.2.2 In P2.0, press
to enter the submenu P2.1 for conductivity setting, press
or
to change submenu: P2.1P2.2 … P2.8. See 7.4 for details.
8.2.3 In P5.0, press
to enter the submenu P5.1 for basic parameter setting, press
or
to change submenu: P5.1P5.2…P5.6. See 7.5 for details.
Main Menu
pH Setting Submenu
P1.1 P1.2 P1.3 P1.4 P1.5
Select pH buffers Set up calibration reminder Check calibration date Select pH calibration mode Restore to factory default
Conductivity Setting Submenu
P2.1 P2.2 P2.3 P2.4 P2.5 P2.6 P2.7 P2.8
Select conductivity buffer solution Select electrode’s constant Set up calibration reminder Check calibration date Select reference temp. Adjust temp. coefficient Adjust TDS factor Restore to factory default
Basic Parameter Setup Submenu
P5.1 P5.2 P5.3 P5.4 P5.5 P5.6
Adjust timing for auto storage Select temp. unit Clear storage Set up auto lock reading mode Adjust date Adjust time
– 24 –
8.3 pH Setting Sub-Menu
(press
or
to switch)
P1.1 — Select pH buffer series (USA–NIST)
1. In measurement mode, long press
to enter P1.0, press
to enter P1.1
2. Press
, USA flashes, press
to choose USANIST, press
to confirm. USA–USA; NIS–NIST; CUS–customize calibration
3. Press
to enter P1.2, or press
to return to measurement
mode.
P1.2 — Set up calibration reminder (No–H00–D00)
1. Press
, “No” flashes, press
to choose NoH00D00
NO–no setting; H00–set hours (0~99); D00–set days(0~99).
2. When “H” flashes, press
, “00” flashes, press
to adjust
hours, Press
to confirm; When “D” flashes, press
, “00”
flashes, press
to adjust days, press
to confirm; When
“No” flashes, press
to confirm.
3. Press
to enter P1.3, or press
mode.
to return to measurement
P1.3 — Check Calibration Time 1. The data and time of last calibration displayed on the left image is: On
June 8, 2016 to 9:08
2. Press
to enter P1.4, or press
to return to measurement
mode.
P1.4 — Select pH Calibration Mode (3P-5P)
1. Press
, 3P flashes, press
to select 3P5P, press
key to confirm. 3P–1~3 points of calibration, 5P–1~5 points of
calibration. Please refer to section 4.3.2.
2. Press
to enter P1.5, or press
key to back to measurement
mode.
P1.5 — Set the Factory DefaultNo–Yes
Press
, “NO” flashes, press
to select NOYes, press
to
confirm, instrument back to measurement mode. No — Not restore; Yes — Restore factory default
– 25 –
8.4 Conductivity Setting Sub-Menu
(press
or
to switch
P2.1 — Select Conductivity Calibration SolutionStd-CUS
1. In P2.0, press
to enter P2.1, see left picture
2. Press
key, Std flashes, press
key to select StdCUS,
press
key to confirm. Std–Standard, CUS–Customize solution.
3. Press
key to enter P2.2, or press
key to return to
measurement mode.
P2.2 — Select electrode’s constant1.0–10.0–0.1–0.01
1. Press
, “1.0” flashes, press
to choose 1.010.00.1
0.01; press
to confirm.
2. Press
to enter P2.3, or press
mode.
to return to measurement
P2.3 — Set up calibration reminder (No–H00–D00)
1. Press
, “No” flashes, press
to choose NoH00D00
NO–no setting; H00–set hours (0~99); D00–set days (0~99).
2. When “H” flashes, press
, “00” flashes, press
to adjust
hours, Press
to confirm; When “D” flashes, press
,
“00”flashes, press
to adjust days, press
to confirm; When
“No” flashes, press
to confirm.
3. Press mode.
to enter P2.4, or press
to return to measurement
P2.4 — Check Calibration Time 1. The data and time of last calibration displayed on the left image is: On
August 6, 2016 to 12:00.
2. Press
to enter P2.5, or press
to return to measurement
mode.
P2.5 –Select reference temperature (15.0°C – 30.0°C)
1. Press
, “25.0°C” flashes, press
or
to adjust temp.
from 15°C to 30°C; press
to confirm.
2. Press mode.
to enter P2.6, or press
to return to measurement
– 26 –
P2.6 –Adjust temp. compensation coefficient (0.00-9.99%)
1. Press
, “2.00” flashes, press
or
to adjust from 0.00-
9.99; press
to confirm.
2. Press
to enter P2.7, or press
mode.
to return to measurement
P2.7 –Adjust TDS Factor (0.40-1.00)
1. Press
, “0.71” flashes, press
or
to adjust from 0.40-
1.00; press
to confirm.
2. Press mode.
to enter P2.8, or press
to return to measurement
P2.8 — Set the Factory DefaultNo–Yes
Press
, “No” flashes, press
to select NoYes, press
to confirm, instrument back to measurement mode. No — Not restore; Yes — Restore factory default
8.5 Basic Parameter Setting Sub-Menu
press
or
to switch
P5.1 — Adjust timing for auto storage
1. In P5.0, press
to enter P5.1 as shown in the left figure.
2. Press
, “:00” flashes, press
or
to set minute (0-59),
press
again, “0:” flashes, press
or
to set hours (0-
99), press
to confirm.
3. Press mode.
to enter P5.2, or press
to return to measurement
P5.2 — Choose Temp. Parameter (°C – °F)
1. Press
, “°C” flashes, press
to choose °C°F, press
to confirm.
2. Press
to enter P5.3, or press
to return to measurement
mode.
P5.3 — Clear storage (No–Yes)
1. Press
, “No” flashes, press
to choose NoYes; press
to confirm. No– not to clear data storage; Yes–clear all data storage
2. Press
to enter P5.4, or press
to return to measurement
mode.
– 27 –
P5.4 — Set up Auto-Lock reading mode (Off–On)
1. Press
, “Of” flashes, press
to choose OffOn, press
to confirm. Off– not set up, On–set up
2. Press
to enter P5.5, or press
to return to measurement
mode.
P5.5 — Adjust Date
1. Press
to choose “Month” “Day” “Year”, press
or
to adjust date, press
to confirm.
2. Press mode.
to enter P5.6, or press
to return to measurement
P5.6– Adjust Time
1. Press
to choose “hour” “minute”, press
or
to
adjust time, press
to confirm.
· 2. Press
to return to measurement mode.
9. USB DATA COMMUNICATION
The instrument uses PC-Link software for data communication through USB
connector and cable. 9.1 Software Interface
Fig-ur1e4- 15
– 28 –
— Stored data aPress “Download” Key to upload the data in the meter to the software, including date, time,
measurements, temperature, and temperature compensation mode. The program will
categorize the data by pH, mV, and Cond.
bPress
after the meter is connected to the computer, or set up auto timing storage
function. In this case, all the measuring data will be uploaded to the software, and will not be stored in the meter. See figure-15. — Model and Numberings
— Calibration information — COM Port #and other buttons
COM Port # is the number for the software to connect with the computer. Every
computer’s COM port is different. In Figure-15, the COM port # is COM4.
Open/Close — Click it to turn on/off the program. When turned on, the LCD will
display Refresh — COM port reset button; Click it to reset the COM port to
COM1. Sync Time — Click it to sync the computer’s time and date to the
meter’s. Download — Click it to upload the data stored in the meter to the
computer. Clear — Click it to clear all the data. Export — Click it to export
all the data to a Microsoft Excel file. Exit — Click it to exit the program.
9.2 Install the software The PC-Link software works for all Windows based system (does not work for Mac). Insert the PCLink disk into the computer, open the PC-Link folder where you will find the folder for PC-Link software and a zipped file for drivers. Typically, users can directly open the file with PCLink icon to use the software. If the meter cannot be connected to the computer, please install the USB driver (in the zipped file) before using the software.
9.3 Choose COM Port Connect the meter to your computer with the USB cable.
Open the PC-Link program. click the arrow icon next to the COM1 Port, and
click the bottom port number, and then click Open. The LCD will
display icon. If port number is hard to be confirmed, users can identify it in
Windows’ Device Manager.
9.4 Run Software 9.4.1 Upload stored data Click Download key to upload the
data stored in the meter to the software, including date, time,
– 29 –
measurements, temperature, and temperature compensation mode. The program will categorize the
data by pH, mV, and Cond.
9.4.2 Real-time storage
aWhen the program is running and meter is connected to computer, press
on the meter
or set up auto timing storage to upload all the measuring data to the software. The data will
not be stored in the meter in this mode.
bThe mode and unit for real-time storage is the same as it is in the meter. Press
or
to make changes.
9.4.3 Data Processing Click “Export” to export all the data to a Microsoft Excel file. Users can process, analyze, and print the data in the Excel file.
10. Recommended pH Electrodes for Specific Applications
Application
Regular water solutions Beverage, beer, or wine analysis Cosmetics Dairy
products (milk, cream, yogurt, mayo, etc.) High-Temperature liquid Low-
temperature liquid Meat Micro sample testing Purified Water (Low ion
concentration samples) Soil Solid or semi-solid samples (cheese, rice, fruit,
etc.) Strong acid samples Strong alkalined samples Surface test (skin, paper,
carpet, etc.) Titration TRIS buffer solutions Viscous liquid samples
Wastewater or emulsion
Ideal Apera pH Electrodes to Use with 820 Series Meter LabSen 211, LabSen 213
LabSen 213 LabSen 851-1, LabSen 851-3 LabSen 823 LabSen 213 LabSen881 LabSen
763 LabSen 241-6, LabSen 241-3 LabSen 803, LabSen 813 LabSen 553
LabSen 753 LabSen 831 LabSen 841 LabSen 371 LabSen 223 LabSen 211, LabSen 213,
LabSen 223 LabSen 223, LabSen851-1 LabSen 333
- Visit http://aperainst.de/electrodes or contact us at +49 202 51988998 for more details.
– 30 –
11. APPENDIX 1 : TABLE OF PARAMETER SETTING
Mode Symbol
Parameter
P1.1 Select Buffer Series
P1.0 pH
P1.2 Set calibration reminder
P1.3
Check calibration date and time
P1.4 Select pH calibration mode
Abbreviation
Content
USANIST CUS
Factory Default
USA
NoH00D00 No
/
3P5P
3P
P1.5 Restore factory default
P2.1
Select conductivity calibration solution
P2.2 Select electrode’s constant
NoYes
No
Std–CUS
Std
1.010.00.01 1.0
P2.3 Set calibration reminder
NoH00D00 No
P2.0
P2.4 Check calibration date and time
/
Conductivit
y
P2.5 Select reference temperature
P2.6
Adjust temperature compensation coefficient
P2.7 Adjust TDS factor
15~30°C 0.00~9.99 0.40~1.00
25°C 2.00% 0.71
P2.8 Restore factory default
NoYes
No
P5.1 Adjust timing for auto storage
/
P5.2 Select temperature unit
/
P5.0 Basic
P5.3 Clear data storage
Parameter P5.4 Set up auto-lock reading mode
/
°C – °F
NoYes
Off–On
P5.5 Adjust date
/
P5.6 Adjust time
/
– 31 –
12. APPENDIX 2: ICONS AND ABBREVIATION
Mode P1.0 pH
P2.0 Conductivity
P5.0 Basic Parameter
Symbol P1.1 P1.2 P1.3 P1.4 P1.5 P2.1 P2.2 P2.3 P2.4 P2.5 P2.6 P2.7 P2.8 P5.1 P5.2 P5.3 P5.4 P5.5 P5.6
Abbreviation /
/
/ / / / /
Others
Stand for Standard buffers Due Calibration
/ Calibration Factory default setting
Solution Cell
Due Calibration
Reference temperature Temperature compensation
coefficient TDS coefficient Factory default setting
Clear readings
United States of America Nist Off On No Yes
– 32 –
13. APPENDIX 3: TABLE OF SELF -DIAGNOSIS SYMBOL
Symbol
Self-Diagnosis Information
Wrong calibration solution or the meter recognition of calibration solution out of range.
Press
key when measuring value is not stable during calibration.
During calibration, the measuring value is not stable for 3 min.
pH electrode zero electric potential out of range (<60mV or >60mV)
pH electrode slope out of range (<85% or >110%)
Enter in pre-set due calibration to remind re-calibration
pH
Conductivity
14. WARRANTY
We warrant this instrument to be free from defects in material and workmanship
and agree to repair or replace free of charge, at option of APERA INSTRUMENTS,
any malfunctioned or damaged product attributable to responsibility of APERA
INSTRUMENTS for a period of THREE YEARS (SIX MONTHS for the probe) from the
delivery.
This limited warranty does not cover any damages due to: accidental damage,
transportation, storage, improper use, failure to follow the product
instructions or to perform any preventive maintenance, modifications,
combination or use with any products, materials, processes, systems or other
matter not provided or authorized in writing by us, unauthorized repair,
normal wear and tear, or external causes such as accidents, abuse, or other
actions or events beyond our reasonable control.
APERA INSTRUMENTS (Europe) GmbH Address: Wilhelm-Muthmann-Str.18 42329
Wuppertal, Germany Email: [email protected] Website: www.aperainst.de Tel.:
+49 202 51988998
– 33 –