Extech Instruments ExStik SX800 Series User manual

SX800 Version2.0
SX800 Series of Portable Electrochemical Meter
Manual
SX811 Portable pH Meter
SX813 Portable Conductivity Meter
SX816 Portable Dissolved Oxygen Meter
SX823 Portable pH/Cond. Meter
SX825 Portable pH/DO Meter
SX836 Portable pH/Cond./DO Meter

SX800 Version2.0

SX800 Version2.0
Table of Contents
1. Introduction ----------------------------------------------------------------------------------------------------------------------
1.1 Measuring parameters ---------------------------------------------------------------------------------------------------
1.2 Basic features -------------------------------------------------------------------------------------------------------------
1.3pH measurement features -----------------------------------------------------------------------------------------------
1.4 Cond. measurement features -------------------------------------------------------------------------------------------
1.5 DO measurement features ----------------------------------------------------------------------------------------------
2. Technical specifications-----------------------------------------------------------------------------------------------------------
3. Instrument Description ----------------------------------------------------------------------------------------------------------
3.1. LCD display----------------------------------------------------------------------------------------------------------------------
3.2. Keypad functions ---------------------------------------------------------------------------------------------------------------
3.3. Meter sockets---------------------------------------------------------------------------------------------------------------------
3.4. Display mode --------------------------------------------------------------------------------------------------------------
3.5. Store, recall and clear readings----------------------------------------------------------------------------------------------
4. pH measurement --------------------------------------------------------------------------------------------------------------------
4.1. pH electrode information------------------------------------------------------------------------------------------------------
4.2. pH calibration consideration -------------------------------------------------------------------------------------------------
4.3. pH calibration --------------------------------------------------------------------------------------------------------------------
4.4. Customer-defined calibration ------------------------------------------------------------------------------------------------
4.5. Sample test -----------------------------------------------------------------------------------------------------------------------
4.6. pH electrode maintenance----------------------------------------------------------------------------------------------------
5. mV measurement--------------------------------------------------------------------------------------------------------------------
6. Conductivity measurement ------------------------------------------------------------------------------------------------------
6.1. Conductivity electrode information------------------------------------------------------------------------------------------
6.2. Conductivity calibration consideration-------------------------------------------------------------------------------------
6.3. Conductivity calibration--------------------------------------------------------------------------------------------------------
6.4. Relations among TDS, salinity, resistivity and conductivity ---------------------------------------------------
6.5. Customer-defined calibration-------------------------------------------------------------------------------------------------
6.6. Sample test------------------------------------------------------------------------------------------------------------------------
6.7. Conductivity electrode maintenance----------------------------------------------------------------------------------
7. DO Measurement------------------------------------------------------------------------------------------------------------
7.1. DO electrode information------------------------------------------------------------------------------------------------
7.2. DO calibration consideration-------------------------------------------------------------------------------------------
7.3. DO calibration--------------------------------------------------------------------------------------------------------------
7.4. Sample test-----------------------------------------------------------------------------------------------------------------
8. Parameter setup----------------------------------------------------------------------------------------------------------------------
8.1. Main menu-------------------------------------------------------------------------------------------------------------------------
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SX800 Version2.0
8.2. Submenu ----------------------------------------------------------------------------------------------------------------------
8.3. Submenu of pH parameter setup ---------------------------------------------------------------------------------------
8.4. Submenu of Cond. parameter setup -----------------------------------------------------------------------------------
8.5. Submenu of DO parameter setup -------------------------------------------------------------------------------------
8.6. Submenu of basic parameter setup -----------------------------------------------------------------------------------
9. USB communication-------------------------------------------------------------------------------------------------------------
9.1. System requirement--------------------------------------------------------------------------------------------------------
9.2. Software interface-----------------------------------------------------------------------------------------------------------
9.3. Load software----------------------------------------------------------------------------------------------------------------
9.4. Automatic connection port------------------------------------------------------------------------------------------------
9.5. Run software ---------------------------------------------------------------------------------------------------------------
10. Meter Kits-------------------------------------------------------------------------------------------------------------------------
10.1. Standard configuration---------------------------------------------------------------------------------------------------
10.2. Selection on electrodes----------------------------------------------------------------------------------------------------
11. Warranty--------------------------------------------------------------------------------------------------------------------------
Appendix I: Parameter setup and factory default setup -----------------------------------------------------------------
Appendix II: Abbreviation Glossary ------------------------------------------------------------------------------------------
Appendix III: Self-diagnosis information --------------------------------------------------------------------------------------
Appendix IV: DO of saturated water vs. temperature -------------------------------------------------------------------
Appendix V: DO of saturated water vs. barometric pressure and temperature ----------------------------------
Appendix VI: DO of saturated water vs. altitude ------------------------------------------------------------------------
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SX800 Version2.0
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1. Introduction
Thanks for buying and using the model SX800 pH/mV/Conductivity/DO Meter (the following called
“meter” in short).
This meter is a perfect combination with the most advanced electronic technology, sensor technology
and software design. The meter includes 6 types and can measure 8 parameters. It is the best portable
water analysis meter with the highest performance and the lowest cost. It is suitable for the trade such
as the mining industry, power plant, water treatment projects and environmental protection, etc.,
especially has more extensive application in the field and spot test.
Before using this meter, please read the operation manual carefully in order to help use and maintain it
correctly. On the basis of improving instrument of performance constantly, we reserve the right of
changing the content of this manual and accessories in case of not notifying in advance.
1.1. Measurement parameters
Measuring parameters
SX811
SX813
SX816
SX823
SX825
SX836
pH/mV
√
√
√
√
Cond./TDS/Sal./Res.
√
√
√
DO
√
√
√
Temp.
√
√
√
√
√
√
1.2. Basic features
●Perfect functions —The microprocessor-based portable meter features
automatic calibration, automatic temperature compensation, menu set-up,
self-diagnostics, due calibration reminding, calibration date checking, automatic
power-off and low voltage display, etc. The multi-parameter meter is able to
measue simultaneously with multiple electrodes, and switch to display.
Please see Diagram -1：three electrodes at most can be fit into the clip
to measure simultaneously.
●Data processing —meet GLP, clock display, manual storage and automatic timing storage,
USB port and data saving in case of blackout.
●Accurate measurement —the meter’s digital filter improves measurement speed and
accuracy. There is reading stability display and automatic lock-up display mode.
●Structure design —IP57 water-proof, able to work under rough conditions, soft rubber case,
the holder at the back side of the meter is convenient for lab. use, two types of power supply:
battery and USB power supply, the durable portable case includes all accessories.
Diagram-1 Combined electrode

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1.3. pH measurement features (suited for model SX811, SX823, SX825 and SX836)
●1-3 point automatic calibration, the meter provides calibration guide and automatic checking
function.
●The meter is able to recognize up to 12 types of pH standard buffer solutions. There are three
options of standard buffer solutions: USAseries, NIST series and Chinese series (CH), there is
also customer-defined solution calibration.
●The meter provides two special modes for pure water and pure water mixed with ammonia.
These special modes offer temperature compensation for pH value, especially suitable for the
electricity and petrochemical industries.
1.4. Conductivity measurement features (suited for model SX813, SX823 and SX836)
●4 calibration points can be chosen, the meter provides calibration guide and automatic
checking function.
●The meter is able to switch among conductivity, TDS, salinity and resistivity measurement
mode. For TDS measurement, the coefficient is adjustable.
●The meter is able to recognize up to 8 types of conductivity standard solutions. There are two
options of standard buffer solutions: USA series and Chinese series (CH), there is also
customer-defined solution calibration.
●The meter has an automatic range feature with automatic non-linear temperature
compensation for pure water and high purity water with conductivity values lower than 10uS/cm
greatly improving accuracy and suitable for the electricity, microelectronics and pharmaceutical
industries.
1.5. DO (Dissolved Oxygen) measurement features (suited for model SX816, SX825 and SX836)
●DO electrode offers a built-in temperature and salinity sensor with automatic temperature
compensation and automatic salinity compensation as well as manual barometric pressure
compensation. The measurement is more accurate.
●Polarographic DO electrode with special DO calibration cover, electrode polarization only
requires 3-5 min, three combined membranes convenient to renew.

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2. Technical Specifications
2.1. Main specifications
Specifications
Models
pH
Range
（-2.00 ~ 19.99）pH
SX811
SX823
SX825
SX836
Resolution
0.01/0.1 pH
Accuracy
±0.01 pH ±1digit
Input current
≤1×10-12 A
Input impedence
≥1×1012 Ω
Stability
±0.01 pH/3h ±1 digit
Temperature compensation
（0 ~ 100）°C（manual or automatic）
mV
Range
-1,999mV ~ 0 ~ 1,999mV
Resolution
- 200 mV ~ 0 ~ 200 mV: 0.1 mV；others:1mV
Accuracy
±0.1% FS ±1digit
Conductivity
Range
Cond.:0~200 mS/cm,divided into five 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
TDS:（0 ~ 100）g/L, Salinity: (0 ~ 100) ppt,
Resistivity: (0 ~ 100) MΩ·cm
SX813
SX823
SX836
Resolution
0.01/0.1/1μS/cm 0.01/0.1 mS/cm
Accuracy
±1.0% FS ±1digit
Temperature compensation
（0 ~ 50）°C（manual or automatic）
Electrode constant
0.1 / 1 / 10 cm-1
Dissolved
Oxygen
Range
（0 ~ 20.00）mg/L(ppm) （0 ~ 200.0）%
SX816
SX825
SX836
Resolution
0.01/0.1 mg/L(ppm) 0.1/1 %
Indicating value accuracy
±0.30 mg/L
Response time
≤30 s（25℃, response at 90%）
Zero accuracy
≤ 0.10 mg/L
Temperature compensation
（0 ~ 45）℃（automatic）
Salinity compensation
（0 ~ 45）ppt（automatic）
Barometric pressure
compensation
（66.0 ~ 199.9）kPa（manual）
Electrode type
Polarographic
Temperature
Range
0~100°C
SX811
SX813
SX816
Resolution
0.1℃

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Accuracy
±0.5℃±1digit
SX823
SX825
SX836
2.2. Other specifications:
Data storage
500 groups
SX811，SX813，SX816
1000 groups
SX823，SX825，SX836
Storage content
Serial number, date, time, measuring value, measuring unit and
temperature value
Output
USB
Power
AAA batteries × 3 (1.5V× 3) / DC5V adaptor ( USB port)
IP rating
IP57 dustproof and waterproof
Dimension & Weight
Meter: (88×170×33 )mm / 313g
Portable case: (360×270×76 )mm / 1.6kg
SX811, SX813
Meter: (88×170×33 )mm / 313g
Portable case: (480×360×95)mm /
3.2kg
SX816, SX823
SX825, SX836

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3. Instrument description
3.1. LCD display：
(1) —Measurement mode icons
(2) —Measurement value
(3) —Timing storage icon. When this icon appears, the meter is in the automatic storage mode
(4) —Date and time display value, and prompts of special display mode
(5) —Units of Date and time
(6) —Units of measurement
(7) —Temperature units (°C and °F)
(8) —Units of pH and conductivity calibration value
(9) —pH and conductivity calibration value, the serial number for storage and recall, and prompts of
special display mode
(10) —Storage and recall icons
M+ —Measurement to be stored icon, RM —Reading to be recalled icon
Diagram - 2 LCD

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(11) —Temperature value and prompts of special display mode
(12) —Automatic reading lock-up icon
(13) —Temperature compensation icons
ATC —automatic temperature compensation, MTC —manual temperature compensation
(14) —Calibration guide icon
(15) —Stability icon of readings
(16) —USB icon，when this icon appears, the meter connects the computer
(17) —Low battery icon, when this icon appears, please renew the battery
3.2. Keypad functions
3.2.1. Keypad operations
Momentary press ----- <1.5 seconds , Long press ----- >1.5 seconds.
3.2.2. Turn on the meter
Press to turn on the meter: LCD full display →display the measurement mode (backlight for one
minute).
3.2.3. Turn off the meter
Only in the measurement mode, press to turn off the meter.
Note: In the calibration mode or the parameter set-up mode, pressing is invalid. Please
press key to return to the measurement mode, then press to turn off the meter.
Diagram - 3 Keypad

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Chart –1 Keypad operations and descriptions
Keypad
Operations
Descriptions
Momentary press
Press this key to turn on or turn off the meter.
Momentary
press
Select measurement parameters:
pH meter: →,
pH/Conductivity meter: →→,
pH/DO meter: →→,
pH/Conductivity/DO meter: →→→.
Long press
In the measurement mode, press this key to enter in the main menu.
Momentary
press
In the measurement mode, press this key to enter in the calibration
mode,
In the recall mode (RM), press this key to return to the measurement
mode,
Cancel any operation to return to the measurement mode.
Momentary
press
In the measurement mode, press this key to turn on or turn off the
backlight,
In the calibration mode, press this key to make calibration,
In the main menu mode, press this key to enter in submenu,
In the submenu mode, press this key to enter in the parameter set-up
mode,
In the parameter set-up mode, press this key to confirm the
parameters.
Long press
In pH measurement mode, press and hold this key to change the
resolution repeatedly: 0.01→ 0.1pH,
In conductivity measurement (or TDS, salinity and resisitivity) mode,
press and hold this key to scroll through →→→
..
In DO mode, press and hold this key to scroll through the DO unit:
mg/L→ppm→%.

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Momentary/
long press
In the mode of manual temperature compensation (MTC), when press
and hold this key, the temperature value flashes, then press this key to
change the temperature value, and press to confirm,
In the measurement mode, press to store the measuring value,
press to recall the stored measuring value,
In the recall mode (RM), press momentarily this key to change the
storage serial number, press and hold this key to change the number
quickly,
In the main menu and submenu mode, press this key to change the
serial number of the main menu and the submenu,
In the parameter set-up mode, press this key to select parameters.
3.3. Meter sockets
Electrode uses BNC, four-pin and eight-pin sockets protected by grey rubber
sealing cap. The following Chart-2 are sockets for model SX811, SX813, SX816,
SX823, SX825 and SX836:
Chart –2 Electrode sockets
Models
Connect Electrode
Description
SX811
SX823
SX825
SX836
Connect pH electrode
BNC socket (middle) —connect pH or ORP electrode,
Four-pin socket (left) —connect temperature probe
SX813
SX823
SX836
Connect Conductivity electrode
Four-pin socket (left) —connect conductivity electrode
SX816
SX825
SX836
Connect DO electrode
Eight-pin socket (right) —connect DO electrode
SX823
SX836
Connect pH and Conductivity electrode
BNC socket (middle) —connect pH or ORP electrode
Four-pin socket (left) —connect conductivity electrode
When connect pH and Conductivity electrode,
temperature sensor is shared.
SX825
SX836
Connect pH and DO electrode
BNC socket (middle) —connect pH or ORP electrode
Four-pin socket (left) —connect temperature probe
Eight-pin socket (right) —connect DO electrode
Diagram-4 Meter socket

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SX836
Connect pH, Conductivity and DO electrode
BNC socket (middle) —connect pH or ORP electrode
Four-pin socket (left) —connect Conductivity probe
Eight-pin socket (right) —connect DO electrode
When connect pH, Conductivity and DO electrode,
electrode, temperature sensor is shared
Chart –3 USB socket functions
Functions
Connect to meter
Description
USB communication
The meter has USB communication
function, connecting the meter to a
computer by USB cable.
Computer or external
power supply
Computer power supply: connect the
meter to a computer by USB cable,
External power supply: use USB cable
and USB adaptor, input voltage:
AC110V~220V.
3.4. Display mode
3.4.1. Reading stability display mode
When the measuring value is stable, smiley icon appears on LCD, see
Diagram –5. If icon does not appear or flash, please do not get the
reading value or make calibration until the measuring value is stable.
3.4.2. Automatic lock-up display mode
Select On from parameter P4.6 to turn on automatic lock-up display function.
When the reading value stabilizes more than 10 seconds, the meter locks the
measuring value automatically and displays HOLD icon, see Diagram –6.
In the HOLD mode, press to release lock-up.
3.5. Store, recall and clear readings
3.5.1. Manual storage
When the measurement is stable, press key, the meter displays
M+ icon and storage serial number on LCD, storing measuring information,
see Diagram –7: the meter stores the first group of the measuring value.
3.5.2. Automatic timing storage
Set the storage timing (eg. 3 minutes) from parameter P4.1,
icon appears on LCD and the meter enters into the timing storage
mode. When press key, icon flashes and the first measuring value
is stored. After 3 minutes, the 2nd measuring value is stored. See
Diagram –8: the meter stores automatically eight measuring values.
When press key, icon stops flashing and the meter stops
automatic storage. In automatic storage mode, manual storage does
Diagram- 5
Diagram - 7
Diagram - 6
Diagram - 8

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not work. Set time 0 from parameter P4.1 to exit from the automatic storage mode.
3.5.3. Recall stored value
In the measurement mode, press key to recall the last stored measuring
value. See Diagram –9: display RM icon and storage serial number. Continue
pressing key and key to recall successively the stored measuring
value. Press and hold key and key to recall quickly the stored
measuring value.
3.5.4. Clear stored value
Select YES from parameter P4.5 to clear all stored value, refer to the item 6.4.
4. pH measurement
4.1. pH electrode information
The meter matches 201T-Q plastic three-in-one combination pH electrode with built-in temperature
sensor and has automatic temperature compensation. Electrode housing adopts polycarbonate
engineering plastics which is corrosion and impact resistant. The pH socket of electrode connects BNC
socket, and the temperature socket connects four-pin socket. When dip pH electrode in the solution,
please stir the solution briefly to eliminate air bubbles and allow it to stay in the solution until a stable
reading is reached.
4.2. pH calibration consideration
4.2.1. Standard buffer solution
The meter uses three series of standard buffer solutions: Chinese series (CH), USA series (USA) and
NIST series (NIST). Please see Chart –2. Please select the buffer solution from parameter P1.1 and
refer to the item 8.3 for details.
Chart - 4 pH standard buffer solution series
Calibration guide icons
pH standard buffer solution series
Chinese series (CH)
USA series (USA)
NIST series (NIS)
Three-point
calibration
1.68 pH and 4.00 pH
1.68 pH and 4.00 pH
1.68 pH and 4.01 pH
6.86pH
7.00 pH
6.86pH
9.18 pH
10.01 pH
9.18 pH
4.2.2. Three-point calibration
The instrument can perform 1-3 point calibration. The first point calibration must use 7.00 pH (or 6.86 pH)
standard solution, then select other standard solution to perform the second and the third point
Diagram- 9

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calibration, see Chart-5. During the calibration process, the instrument displays the electrode slope of
acidity range and alkalinity range respectively.
Chart - 5 Calibration mode
Description
Chinese standard
(CH)
USA standard
(USA)
NIST standard
(NIST)
Calibration guide
icons
Suited range
One-point
calibration
6.86 pH
7.00 pH
6.86 pH
Accuracy
≤±0.1pH
Two-point
calibration
6.86 pH,
4.00 pH or 1.68pH
7.00 pH,
4.00 pH or 1.68pH
6.86 pH,
4.01 pH or 1.68pH
0~7.00 pH
6.86 pH and 9.18pH
7.00 pH and
10.01pH
6.86 pH and 9.18pH
7.00~14.00
pH
Three-point
calibration
6.86 pH, 4.00 pH or
1.68pH and 9.18 pH
7.00 pH, 4.00 pH or
1.68pH and 10.01 pH
6.86 pH, 4.01 pH or
1.68pH and 9.18 pH
0~14.00 pH
4.2.3. Calibration intervals
Calibration intervals depend on the sample, the electrode performance, and the required accuracy. For
high accuracy measurements (≤ ±0.02pH), the meter should be calibrated immediately before taking a
measurement. For general accuracy (≥±0.1pH), the meter can be calibrated and used for approximately
one week or longer before the next calibration. The meter must be recalibrated in the following
situations:
(a) New probe, or probe that is unused for a long period of time
(b) After measuring acids (pH<2) or alkaline solutions (pH>12)
(c)After measuring a solution that contains fluoride or a concentrated organic solution
(d) If the solution’s temperature differs greatly from the calibration solution temperature
4.2.4. Due calibration
Pre-set calibration interval (begin from the date of setup) to remind due
calibration in a preset period. Please refer to parameter P1.2 (Item 8.3).
When setup date comes, Er 6 icon appears at the bottom right of LCD
(see Diagram –10). The meter can continue operation in this situation.
This is just to remind the user to perform calibration to ensure measurement
accuracy. Er 6 icon disappears until the calibration is done, or when select
No from parameter P1.2.
4.2.5. Check calibration date
Check the date and time of the last calibration to decide whether new calibration is needed. Please refer
to parameter setting P1.3 (Item 8.3).
4.2.6 Change temperature value manually
When the temperature probe does not connect to the meter, press and hold key or key,
temperature value flashes, then press (or press and hold) key or key to change the
Diagram- 10

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temperature value, and press key to make confirmation.
4.3. pH calibration ( take an example of three-point calibration)
4.3.1. Press key to enter into the calibration mode, “CAL 1” flashes at the top right of LCD and
“7.00 pH ”flashes at the bottom right of LCD, indicating using pH 7.00 buffer solution to make the 1st point
calibration.
4.3.2. Rinse pH electrode in pure water, allow it to dry, and submerge it in pH7.00 buffer solution. Stir the
solution briefly and allow it to stay in the buffer solution until a stable reading is reached. The meter’s
display will show scanning and locking process of calibration buffer solution at the bottom right of LCD.
Er 2 displays if press key before the value is locked. See chart –6.
4.3.3. When the meter locks 7.00 pH, stable icon displays on LCD. Press key to calibrate the
meter. End icon appears after calibration is done. The 1st point calibration is finished, meanwhile, the
meter’s display will show at the top right a blinking CAL2, and show at the
bottom right blinking 4.00pH and 10.01pH alternately, indicating using pH4.00
or pH10.01 buffer solution to make the 2nd point calibration.
4.3.4. Take out pH electrode，rinse it in pure water, allow it to dry, and
submerge it in pH4.00 buffer solution. Stir the solution briefly and allow it to
stay in the buffer solution until a stable reading is reached. The meter’s
display will show scanning and locking process of calibration buffer solution
at the bottom right of LCD. When the meter locks 4.00 pH, stable
icon displays on LCD. Press key to calibrate the meter. End icon and
electrode slope of acidity range display after calibration is done, meanwhile,
the meter’s display will show at the top right a blinking CAL3, and show at
the bottom right blinking 10.01pH, indicating using pH10.01 buffer solution
to make the 3rd point calibration.
4.3.5. Take out pH electrode，rinse it in pure water, allow it to dry, and
submerge it in pH10.01 buffer solution. Stir the solution briefly and allow it to
stay in the buffer solution until a stable reading is reached. The meter’s display
will show scanning and locking process of calibration buffer solution at the
bottom right of LCD. When the meter locks 10.01 pH, stable icon 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 Diagram–11 for the above calibration process.

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4.3.6. During the calibration process, press key to exit from the calibration
mode. The meter can perform one-point, two-point and three-point calibration.
Calibration guide icons appear on LCD.
4.4. Customer-defined calibration
(take an example of 1.60pH and 6.50pH calibration solution)
4.4.1. Select CUS from parameter P1.1 (please refer to Item 8.3 for customer-defined solution). The
meter enters into Customer-defined calibration mode. When press key, the meter’s display show a
blinking CAL1 icon at the top right of LCD, indicating the meter enters into the 1st point customer-defined
calibration.
4.4.2. Rinse pH electrode in pure water, allow it to dry, and submerge it in pH1.60 buffer solution. Stir the
solution briefly and allow it to stay in the buffer solution until a stable reading is reached. When LCD
displays the stable measuring value and icon, press key and the measuring value flashes.
Press key or key to adjust the measuring value to 1.60, then press key to calibrate the
meter. After calibration is done, LCD at the top right shows blinking CAL2 icon, indicating the meter
enters into the 2nd point customer-defined calibration.
4.4.3. Rinse pH electrode in pure water, allow it to dry, and submerge it in pH 6.50 buffer solution. Stir the
solution briefly and allow it to stay in the buffer solution until a stable reading is reached. When LCD
displays the stable measuring value and icon, press key and the measuring value flashes.
Press key or key to adjust the measurement value to 6.50, then press key to calibrate the
meter. After calibration is done, the meter returns to the measurement mode. For customer-defined
calibration, LCD does not show electrode calibration guide icons.
Note: For manual temperature compensation (MTC), when press key, the temperature value
flashes. Press key or key to adjust the temperature value, and then press key, pH
measuring value flashes.
4.4.4. Notes
(a) The meter can perform 1-2 point customer-defined calibration. When the 1st point calibration is done,
press key, the meter exits from calibration mode. This is one-point customer-defined calibration.
When the 2nd point calibration is done, the meter returns to the measurement mode automatically.
(b) The value set in “Customer-defined”is at a fixed temperature. The meter is suggested to perform
calibration and measurement at the same temperature to avoid large error. The meter cannot recognize
customer-defined calibration solution.
4.5. Sample test
4.5.1. Rinse pH electrode in pure water, allow it to dry, and submerge it in sample solution. Stir the
solution briefly and allow it to stay in the sample solution until the stable value and icon appears on
LCD, get the reading which is pH value of sample solution, please refer to Diagram-12 for calibration and
Diagram- 11

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measurement process of pH meter.
Diagram –12 Calibration and measurement process of pH meter
4.5.2. pH measurement of pure water
The meter is able to set up pH measurement mode of pure water with
temperature compensation for pH value from parameter setup P1.5
(please see Item 8.3). “PU-1”icon displays at the right top of LCD, please
refer to Diagram –13.
4.5.3. pH measurement of pure water mixed with ammonia
The meter is able to set up pH measurement mode of pure water mixed with
ammonia with temperature compensation for pH value from parameter setup
P1.6 (please see Item 8.3). “PU-2”icon displays at the right top of LCD,
please refer to Diagram –14.
Note: In parameter setup, either “PU-1”or “PU-2”measurement mode
can be selected, but both can not work at the same time.
4.5.4. Self-diagnosis information
During the process of calibration and measurement, the meter has self-diagnosis functions, indicating
the relative information as below, please refer to chart –6.
Diagram-13
Diagram-14
Press to turn
on the meter.
Press key to
enter into the
calibration mode.
Submerge the
electrode in pH7.00
solution, press
key when icon
appears.
After the 1st point
calibration is done,
press key to
enter into the
measurement mode.
1st point
calibration
Sample
Test
2nd point
calibration
3rdpoint
calibration
After the 2nd point
calibration is done,
press key to
enter into the
measurement mode.
After the 3rd point
calibration is done,
the meter enters into
the measurement
mode automatically.
Submerge the
electrode in pH4.00
solution, press
key when icon
appears.
Submerge the
electrode in pH10.01
solution, press
key when icon
appears.

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Chart –6 Self-diagnosis information of pH measurement mode
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.
Press key when measuring value
isnotstable during calibration.
Press key when icon appears.
During calibration, the measuring value
is not stable for ≥3min.
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）
1.Check whether there are bubbles in glass bulb.
2.Check whether pH buffer solution is correct.
3.Replace with new pH electrode.
pH electrode slope out of range
（<85% or >110%）
Enter in pre-set due calibration to
remind calibration
Press key to perform calibration or cancel due
calibration setup from parameter P1.2.
4.5.5. pH temperature principle
Please note that the closer the temperature of the sample solution to the calibration solution, the more
accurate readings.
4.5.6. Factory default setting
For factory default setting, please refer to parameter P1.6 (Item 8.3). Per parameter P1.6, all calibration
data is deleted and the meter restores to the theory value (zero electric potential of pH is 7.00, the slope
is 100%). Some functions restore to the original value (refer to Appendix-I). 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 not be retrievable.
4.6. pH electrode maintenance
4.6.1. 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 pure water before taking a
measurement. Insert the electrode and tighten the capsule after measurements to prevent the solution
from leaking. If the soak solution is turbid or moldy, replace the solution.
The electrode should not be soaked in pure water, protein solution or acid fluoride solution for long
periods of time. In addition, do not soak the electrode in organic silicon lipids.
For best accuracy, always keep the meter clean and dry, especially the meter’s electrode and electrode
socket. Clean with medical cotton and alcohol if necessary.
4.6.2. Calibration buffer solution
For calibration accuracy, the pH of the standard buffer solution must be reliable. The buffer solution
should be refreshed often, especially after heavy use.

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4.6.3. Protect glass bulb
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, wash the electrode with pure water and then throw off the excess water on the electrode.
Do not clean the glass bulb with a tissue for it will affect the stability of the electrode potential and
increase the response time. The electrode should be thoroughly cleaned if a sample sticks to the
electrode. Use a solvent if the solution does not appear clean after washing.
4.6.4. Renew glass bulb
Electrodes that have been used over a long period of time, will become ageing. Submerge the electrode
in 0.1mol/L hydrochloric acid for 24 hours, then wash the electrode in pure water, then submerge it in
soaking solution for 24 hours. The method to prepare 0.1mol/Lhydrochloric acid: dilute 9mLhydrochloric
acid in pure water to 1000mL. For serious passivation, submerge the bulb in 4% HF (hydrofluoric acid)
for 3-5 seconds, and wash it in pure water, then submerge it in the soaking solution for 24 hours to renew
it.)
4.6.5. Clean contaminated glass bulb and junction (see Chart –7)
Chart –7 Clean contaminated glass bulb and junction
Contamination
Abluent
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)
Paint
Dilute bleacher, peroxide
Note: The electrode housing is polycarbonate. When use abluent, take cautions on carbon
tetrachloride, trichlorethylene, tetrahydrofuran, acetone, etc which will dissolve the housing and
invalidate the electrode.
5. mV measurement:
5.1. ORP measurement
Press key, and switch the meter to mV measurement mode. Connect ORP electrode (need
purchase it separately) 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 which is ORP value.
ORP means Oxidation Reduction Potential. The unit is mV.
5.2. Notes of ORP measurement
5.2.1. 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.