Apera Instruments 800 Series User manual

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800 Series
Benchtop pH/Conductivity Meter
Instruction Manual
PH800 Lab pH Meter
EC800 Lab Conductivity Meter
PC800 Lab pH/Conductivity Meter
APERA INSTRUMENTS, LLC
www.aperainst.com
v3.3

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Table of Contents
1Brief Introduction............................................................................................................- 3 -
1.1 Measuring Parameters......................................................................................................... - 3 -
1.2 Features and Functions........................................................................................................ - 3 -
1.3 Features in pH Measurement (Applicable Models: PH800, PC800)......................................... - 4 -
1.4 Features in Conductivity Measurement (Applicable Models: EC800, PC800) .......................... - 4 -
2What’s in the Box? ..........................................................................................................- 4 -
3Technical Specifications ...................................................................................................- 5 -
4Instrument Description....................................................................................................- 6 -
5pH Measurement ..........................................................................................................- 10 -
5.1 Preparation....................................................................................................................... - 10 -
5.2 pH Electrode Information .................................................................................................. - 10 -
5.3 Information regarding pH Calibration................................................................................. - 11 -
5.4 pH Calibration (Take 3-point calibration as an example)...................................................... - 13 -
5.5 Sample Measurement ....................................................................................................... - 14 -
5.6 Maintenance of the pH Electrode....................................................................................... - 15 -
6mV Measurement..........................................................................................................- 16 -
6.1 mV Measurement.............................................................................................................. - 16 -
6.2 Notes on ORP measurement.............................................................................................. - 17 -
7Conductivity Measurement ...........................................................................................- 17 -
7.1 Set up flexible Electrode Holder (refer to 4.1) ..................................................................... - 17 -
7.2 Information regarding the Conductivity Electrode .............................................................. - 17 -
7.3 Information regarding Conductivity Calibration .................................................................. - 18 -
7.4 Conductivity Calibration (take 1413 μS/cm2 as an example) ................................................ - 20 -
7.5 TDS, Salinity, Resistivity & Conductivity.............................................................................. - 20 -
7.6 Sample Test....................................................................................................................... - 21 -
7.7 Maintenance of the Conductivity Electrode........................................................................ - 22 -
8Parameter Setting..........................................................................................................- 22 -
9USB Data Communication..............................................................................................- 27 -
10 Recommended pH Electrodes for Specific Applications ...............................................- 29 -
11 Warranty ...................................................................................................................- 29 -
12 APPENDIX 1: TABLE OF PARAMETER SETTING AND FACTORY DEFAULT SETTING...........- 30 -
13 APPENDIX 2: ICONS AND ABBREVIATION....................................................................- 31 -
14 APPENDIX 3: TABLE OF SELF-DIAGNOSIS SYMBOL .......................................................- 32 -

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1 BRIEF INTRODUCTI ON
Thank you for purchasing 800 Series Benchtop pH/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
PH800
EC800
PC800
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
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.

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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: PH800, PC800)
1 to 3 points auto calibration with calibration guide and auto-check function .
Automatic recognition of up to 8 types of calibration solutions. Two series of standard solutions
for choice: USA and NIST.
Automatic display of electrode slope.
1.4 Features in Conductivity Measurement (Applicable Models: EC800, PC800)
1 to 4 points auto calibration with calibration guide and auto-check function.
Single-tap switch among conductivity, TDS, salinity, and resistivity
2 WHAT’S IN THE BOX?
Content
Quantity
PH800
EC800
PC800
1
PH800 Lab pH Meter
1
√
2
EC800 Lab Conductivity Meter
1
√
3
PC800 Lab pH/Conductivity Meter
1
√
4
201T-F 3-in-1 Combination pH Electrode ATC
1
√
√
5
2301T-F Conductivity Electrode ATC
(ATC，k=1.0)
1
√
√
6
pH Standard Buffer (4.00 pH,7.00 pH,10.01pH/50mL)
1 for each
√
√
7
Conductivity Standard Solution
(84μS,1413μS,12.88mS/50mL)
1 for each
√
√
8
9V Power Adapter
1
√
√
√
9
Flexible Electrode Holder
1
√
√
√
10
PC-Link Software Disk
1
√
√
√
11
USB Cable
1
√
√
√
12
Instruction Manual
1
√
√
√
13
Quick Manual
1
√
√
√

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3 TECHNIC AL SPECIFICATIONS
Technical Parameters
Applicable
Models
pH
Measuring Range
（-2.00 ~ 19.99）pH
PH800
PC800
Resolution
0.1/0.01 pH
Accuracy
±0.01 pH ±1 digit
Temperature
Compensation Range
（0 ~ 100℃）Automatic or Manual
mV
Measuring Range
±1999mV
Resolution
1mV
Accuracy
±0.1% FS ±1 digit
Cond.
Measuring Range
Conductivity: (0~200) mS/cm，including 5 ranges:
(0.00~19.99)μS/cm, (20.0~199.9)μS/cm,
(200~1999)μS/cm, (2.00~19.99)mS/cm,
(20.0~199.9)mS/cm.
EC800
PC800
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
(10.0~99.9)g/L
Salinity: (0~100) ppt, including 2 ranges:
(0 ~ 9.99) ppt, (10.0 ~99.9) ppt,
Resistivity: (0~100) MΩ·cm, including 6 ranges:
(0 .0~ 99.9)Ω·cm, (100~ 999)Ω·cm,
(1.00~ 9.99)KΩ·cm, (10.0~ 99.9)KΩ·cm,
(100~ 999)KΩ·cm, (1.0~ 99.9)MΩ·cm,
Resolution
Conductivity： 0.01/0.1/1μS/cm，0.01/0.1 mS/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：0.1/1Ω·cm, 0.01/0.1/1 KΩ·cm, 0.1 MΩ·cm.
Accuracy
±1.0% FS ±1 digit
Temperature
Compensation Range
（0 ~ 50℃）Automatic or Manual
Electrode Constant
0.1 / 1 / 10 cm-1
Temp.
Measuring Range
0 to 100℃
PH800
EC800
PC800
Resolution
0.1℃
Accuracy
±0.5℃ ±1 digit
Other
Data Storage
PH800/EC800：500 Groups；PC800：1000 Groups
Storage Content
Numberings, Date, Time, Measurements, Unit, Temperature
Data Output
USB
IP Rating
IP54 Waterproof and Dustproof
Calibration
pH：1~3 points，Conductivity：1~4 points

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4 INSTRUMENT DESCRIPTION
4.1 LCD Display
① —— Measuring parameters
② —— Measuring value
③ —— USB data communication. The meter is connected to your PC when this icon is
displayed.
④ —— Timing storage
⑤ —— Date, time, and reminder icons
⑥ —— “Date” and “Time”
⑦ —— Measuring unit
⑧ —— Measuring unit in calibration
⑨ —— Calibration value, numberings of data storage, and reminder icons
⑩ —— Temperature unit
⑪ —— Data storage and display icon
M+— Data storage; RM— Recall saved data
⑫ —— Temperature and reminder icons
⑬ —— ATC—Auto Temperature Compensation; MTC— Manual Temperature Compensation
⑭ —— Completed calibration icons
⑮ —— Auto-Lock reading mode
⑯ —— Stable reading icon
Figure-1

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4.2 Keypad
Short Press — <1.5 s；Long Press — >1.5 s
Table-1 Keypad Operation and Functions
Keypad
Operation
Functions
Short Press
Power on/off
Short Press
Choose measuring mode:
pH Meter： →
pH/Conductivity Meter： → →
Long Press
Enter parameter setting
Short Press
Enter calibration mode
Short Press
In pH mode: choose resolution: 0.1 pH→0.01pH
In conductivity mode, choose measuring mode: → → →
Short Press
In calibration mode: press to calibrate
In parameter setting mode: press to confirm choice
Short Press
Cancel any operation, the meter goes back to measurement mode
Short Press
Save measuring data
Long Press
Recall saved measuring data
Short Press
or Long
Press
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.
Figure-2

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4.3 Connectors
Table-2 Connectors of Different Models
Table–3 Connector Name and Type
special notes: don't pull out the power plug when the meter is working. It should be pulled out only
after the meter is turned off.
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
Connectors
Model
PH800 pH Meter
EC800 Conductivity Meter
PC800 pH/Conductivity Meter
Icon
Connector Name
Connector Type
REF
Reference Electrode Plug
Φ2 Banana Plug
pH/mV
pH Electrode and ORP Electrode Plug
BNC Connector
TEMP
Temperature Plug (sharing for pH and conductivity)
RCA Connector
COND
Conductivity Plug
BNC Connector
USB
USB Communication Plug
Standard Four Core Connector
DC9V
DC9V Power Plug
Φ2.5 Power Plug
Figure-3

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appear and stay before record the readings or conduct calibrations.
4.4.2 Auto-Lock Display Mode
In parameter setting P5.4,select “On” to turn on the auto-lock display mode,
in which the reading will be automatically locked after icon
has been stably displaying 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 2.
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.
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
Figure-4
Figure-5
Figure-6
Figure-7

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5 pH Measurement
5.1 Preparation
5.1.1 Set up the 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.
5.1.2 Connect the power adapter
Plug the power adapter tightly into the DC9V socket. The power’s voltage should meet the
requirements listed on the power adapter.
5.1.3 Things needed in addition to what’s included in the box
A clean cup, distilled or deionized water (8-16oz), and tissue papers for rinsing and drying the probe.
5.2 pH Electrode Information
5.2.1 pH Electrode
The meter comes with the 201T-F 3-in-1 combination electrode with a built-in temperature sensor,
which enables the automatic temperature compensation. This electrode is only suitable for regular
water solutions’ pH testing. Please refer to Section 10 for ideal pH electrodes to use for other specific
applications. The electrode’s housing adopts polycarbonate materials, which is resistant to shocks
and corrosion. A 3M KCL storage bottle comes with the electrode, which is for storing the electrode
when not in use to keep the sensitivity of the probe.
5.2.2 Technical Specifications of the 201T-F pH Electrode
Measurement Range: 0 - 14 pH, 0 - 80˚C (32 – 176˚F)
Junction: Single Ceramic
Reference Electrode: Ag/AgCl
Connector: BNC/RCA
Size: ø12*160 mm
Temperature unit: 30KΩ Thermistor
5.2.3 Electrode Connectors
The pH electrode has two connectors: the BNC connector connects the pH probe; the RCA
connector connects the temperature sensor. Plug these two connectors into ‘pH/mV” and “TEMP”
sockets. Please note not to pull the cables in case of poor contact. Please keep the connectors clean
and dry. Refer to section 4.7 regarding how to properly maintain the pH electrode.
5.2.4 How to Measure with the Electrode
Screw off the KCL storage bottle, and put it aside (do not dump or spill the KCL solution). Prepare a

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cup of distilled or deionized water, and rinse the electrode in it for a few seconds. Gently shake the
probe to remove excess water, and dry it with clean tissue paper (DO NOT rub or wipe the probe,
just use paper to dap off excess water). Gently stir the electrode for a few seconds after it’s dipped
into the test solution and then let it stand still. Wait for the stable measurement (a smiley face appears
and stays) and then record the readings. When test is finished, place the electrode in the storage
bottle and tighten the cap in order to keep the sensitivity of the pH sensor.
Notes:
1) This default 201T-F electrode will NOT give accurate and stable pH readings when testing purified
water such as distilled or deionized water. To measure distilled or deionized water’s pH, users need to
use a specialized pH electrode with the meter such as LabSenTM 803 Pure Water pH Electrode. Contact
us at 1-614-285-3080 or [e-mail] for more details. When testing purified water like spring
water or drinking water, it will take longer for the readings to get stabilized (typically 3-5 minutes) because
there is very few ions left to be detected by the sensor in those purified water.
2) Purified water such as distilled water and deionized water are recommended for only rinsing the
probe for the best result.
3) The 201T-F pH Electrode is NOT suitable for testing high-temperature samples (>176˚F). Testing
high-temperature samples could cause permanent damage to the electrode. A specialized electrode such
as LabSenTM 213 (up to 225˚F) should be used in this situation.
4) The electrode housing is polycarbonate. When using cleaning solutions, take cautions on carbon
tetrachloride, trichlorethylene, tetrahydrofuran, acetone, etc., which will dissolve the housing and
invalidate the electrode.
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
3 Points
Calibration
1.68 pH & 4.00 pH
1.68 pH & 4.01pH
7.00 pH
6.86 pH
10.01pH & 12.45 pH
9.18 pH & 12.45 pH
5.3.2 pH Calibration Modes
Users can adopt 1 to 3 points to calibrate as needed. 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

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3rd points (see 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
NIST
Calibration icon
When to adopt
1-Point
Calibration
7.00 pH
6.86 pH
accuracy≥ ±0.1 pH
2-Point
Calibration
7.00 pH→
4.00 pH or 1.68 pH
6.86 pH→
4.01 pH or 1.68 pH
Measuring range:
0 to 7.00 pH
7.00 pH→
10.01 pH or 12.45 pH
6.86 pH→
9.18 pH or 12.45 pH
Measuring range:
>7.00 pH
3-Point
Calibration
7.00pH→
4.00 pH or 1.68 pH→
10.01pH or 12.45 pH
6.86pH→
4.01 pH or 1.68 pH→
9.18 pH or 12.45 pH
Wide measuring range
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
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. 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
Figure-8

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to re-calibrate. For details, please see parameter setting P1.3 (Section 7.3)
5.3.6 pH Isothermal Measurement Principle
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. This principle is
recommended to follow when conducting tests for the best result. Example: If users were to test
samples at 150˚F, we recommend warming up the calibration solutions to the same temperature
before performing calibrations in order to get the most accurate readings.
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 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 willshow 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 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 buffer solution to make the 3rd point calibration.
Figure-9

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Submerge the
electrode in pH4.00
solution, press
key when icon
appears.
Submerge the
electrode in pH7.00
solution, press
key when icon
appears.
After the 1st point
calibration is done,
press key to
enter the
measurement mode.
Press to turn
on the meter.
Press key to
enter the calibration
mode.
Sample
Test
1 st point
calibration
2 n d point
calibration
3 r d point
calibration
After the 2nd point
calibration is done,
press key to
enter the
measurement mode.
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.
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 and stays 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.
5.5 Sample Measurement
5.5.1 Rinse the pH electrode in distilled water or distilled 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.
5.5.2 Self-Diagnosis Information
Among the calibration and measurement procedure, the meter has self-diagnosis function, reminding
related information. Please refer to table-6.
Table – 6 Self-diagnosis information
Display Icons
Contents
Checking
Wrong pH buffer solution or the buffer
solution out of range.
1. Check whether pH buffer solution is
correct.
2. Check whether the meter connects
the electrode properly.
3. Check whether the electrode is
damaged.
Figure-10

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Press when reading is not stable during
calibration.
Press key when icon appears and
stays.
During calibration, readings being unstable for
over 3 minutes
1. Check whether there are bubbles in
glass bulb.
2. The pH Electrode is aged. Replace a
new one.
pH electrode zero electric potential out of
range (<-60mV or >60mV)
1. Check whether there are bubbles in
glass bulb.
2. Check whether pH buffer solution is
correct.
3. Check whether pH electrode is
damaged.
4. The pH electrode is aged. Replace a
new one
pH electrode slope out of range
(<85% or >110%)
The pre-set calibration due date is reached.
Time to do perform a new calibration
Press key to perform calibration or
cancel due calibration setup in parameter P1.2.
* If you find any air bubble in the glass bulb of the pH sensor, simply shake the probe for a few
times to remove it. The existence of an air bubble in the glass bulb will significantly decrease the
stableness of measurement.
5.5.3 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.
5.6 Maintenance of the pH Electrode
5.6.1 Daily maintenance
The soaking solution contained in the supplied protective bottle is used to maintain activation in the
glass bulb and junction. Loosen the capsule, remove the electrode and rinse in distilled water
before taking a measurement. Insert the electrode and tighten the capsule after measurements to
prevent the solution from leaking. If the soaking solution is turbid or moldy, replace the KCL
solution (SKU: AI1107). Note: using other brands’ storage solutions could cause permanent
damage to the pH electrode because different chemicals are used. The electrode should not be
soaked in distilled water, protein solution or acid fluoride solution for long periods of time. In
addition, do not soak the electrode in organic lipids.
5.6.2 Calibration buffer solution
For calibration accuracy, the pH of the standard buffer solution must be reliable. The buffer solution

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should be refreshed often, especially after heavy use. We recommend 10-15 times of use before
replacing the pH buffers.
5.6.3 Protect the glass bulb sensor
The sensitive glass bulb at the front of the combination electrode should not come in contact with
hard surfaces. Scratches or cracks on the electrode will cause inaccurate readings. Before and after
each measurement, the electrode should be washed with distilled water and dried. If a sample sticks
to the electrode or it’s contaminated, the electrode should be thoroughly cleaned using a soft brush
and then rinsed with distilled water. After that, soak it in the KCL solution again for 6 hours.
5.6.4 Renew 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 distilled water, then submerge
it in KCL soaking solution for 24 hours. The method to prepare 0.1mol/L hydrochloric acid: dilute 9mL
hydrochloric acid in distilled water to 1000mL. For serious passivation, submerge the bulb in 4% HF
(hydrofluoric acid) for 3-5 seconds, and wash it in distilled water, then submerge it in the soaking
solution for 24 hours to renew it.
5.6.5 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 mV 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 (the 301Pt-C combination ORP
electrode is sold separately) and dip it in sample solution, stir the solution briefly and allow it to
stay in the solution until icon appears and stays, then record the reading. ORP means
Oxidation Reduction Potential. The unit is mV.
Connect Ion electrode and reference electrode to measure Ion electric potential.

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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 Solution（222mV±15mV，25℃）
˚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:
(a) For inorganic pollutant, submerge the electrode in 0.1mol/L dilute hydrochloric acid for 30
minutes, then wash it in distilled 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 distilled
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 distilled water, then submerge it in the soaking solution for 6 hours.
7 CONDUCTIVI TY MEASURE MENT
7.1 Set up flexible Electrode Holder (refer to 4.1)
7.2 Information regarding the Conductivity Electrode
7.2.1 Conductivity electrode
EC800 and PC800 are equipped with model 2301T-F plastic conductivity electrode with constant
K=1.0 and a built-in temperature sensor, which allows for automatic temperature compensation. The
electrode housing is POM plastic which is corrosion resistant and impact resistant. 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

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Table–9 Electrode constant and measuring range
Range
＜20 μS/cm
1.0 μS/cm to 100 mS/cm
＞100mS/cm
Conductivity
electrode
constant
K=0.1
K=1.0
K=10
Standard
solution
84μS/cm
84μS/cm
1413 μS/cm
12.88 mS/cm
111.8 mS/cm
Electrode’s
model
DJST-0.1-F
conductivity
electrode
2301T-F conductivity electrode
2310T-F conductivity
electrode
Note: When testing ultra-distilled water with conductivity less than 1.0 μS/cm, a flow test should be
conducted in a flow cell.
* 1000 µS/cm2 = 1 mS/cm2
7.3 Information regarding Conductivity Calibration
7.3.1 Conductivity Standard Calibration Solutions
The meter uses conductivity standard solution of 84 μS/cm, 1413 μS/cm, 12.88 mS/cm and 111.8
mS/cm. The meter can recognize the standard solution automatically, and can perform 1 to 4 points
of calibration. The calibration indication icons correspond to the four standard values as shown in
Table-10.
Table-10 Conductivity Calibration Solutions
Calibration Icons
Calibration Solutions
84 μS/cm
1413 μS/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.

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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˚C to 30˚C. 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).
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 pay attention not to contaminate the solutions
during usage (especially for standard solution of low concentration like 84μS/cm). The contaminated
standard solution will affect accuracy. Before submerging the electrode in standard solution, please
rinse the electrode with distilled water and allow it to dry.
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 P2.2 (Section 7.4). When the preset
time is reached, Er6 icon will be displayed at the lower right corner of
Figure-11

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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 P2.2 in parameter setting.
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 P2.3 (Section 7.4)
7.4 Conductivity Calibration (take 1413 μS/cm2as an example)
7.4.1 Rinse the electrode in distilled water, allow it to dry, wash with a little
of standard solution and submerge it in 1413μS/cm standard solution. Stir
briefly and allow it to stay in the solution until a stable reading is reached.
7.4.2 Press key to enter the calibration mode. The meter’s display
will show blinking―CAL at the top right, and scanning and locking
process of calibration solution at the bottom right. Er2icon will appear if
press before value is stable. See table-6
7.4.3 When the meter locks 1413 μS, 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 P2.6. The factory default setting is 0.71 and please refer to section 7.4. Salinity and
resistivity are 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
Figure-12