Apera Instruments SX811-PW User manual

- 1 -
SX811-PW Portable pH Meter
for Purified Water
Instruction Manual
APERA INSTRUMENTS (Europe) GmbH
www.aperainst.de

- 2 -
1Brief Introduction ............................................................................................................- 4 -
1.1 Features............................................................................................................................... - 4 -
1.2 Features of the LabSen 803 Glass pH Electrode ..................................................................... - 4 -
1.3 Proper use and maintenance of the LabSen 803 Electrode..................................................... - 5 -
2Technical Specifications....................................................................................................- 6 -
2.1 Instrument Technical Specs................................................................................................... - 6 -
2.2 Others ................................................................................................................................. - 6 -
2.3 Electrode Technical Specs ..................................................................................................... - 7 -
3Instrument Description....................................................................................................- 7 -
3.1 LCD Display.......................................................................................................................... - 7 -
3.2 Keypad ................................................................................................................................ - 8 -
3.3 Display mode..................................................................................................................... - 10 -
3.4 Data storage, recall, and delete........................................................................................... - 10 -
4pH Measurement...........................................................................................................- 11 -
4.1 Information regarding pH Calibration.................................................................................. - 11 -
4.2 pH Calibration (use 3-point, USA Standard as an example)................................................... - 13 -
4.3 Customized Calibration....................................................................................................... - 14 -
4.4 Sample test........................................................................................................................ - 15 -
5mV measurement ..........................................................................................................- 17 -
5.1 ORP measurement............................................................................................................. - 17 -
5.2 Notes of ORP measurement ............................................................................................... - 17 -
6Parameter Setup............................................................................................................- 17 -
6.1 Main menu ........................................................................................................................ - 17 -
6.2 Submenu ........................................................................................................................... - 17 -
6.3 Submenu of pH parameter setup........................................................................................ - 18 -
6.4 Submenu of basic parameter setup..................................................................................... - 20 -
7USB Communication ......................................................................................................- 21 -
7.1 System Requirement.......................................................................................................... - 21 -
7.2 Software Interface ............................................................................................................. - 21 -
7.3 Load software.................................................................................................................... - 22 -
7.4 Automatic connection port................................................................................................. - 23 -
7.5 Run software ..................................................................................................................... - 23 -
7.6 Storage during operation.................................................................................................... - 23 -

- 3 -
7.7 Data processing.................................................................................................................. - 23 -
8What’s in the box...........................................................................................................- 23 -
9Warranty .......................................................................................................................- 24 -
10 Appendix I: Parameter setup and factory default setup...............................................- 24 -
11 Appendix II: Abbreviation glossary...........................................................................- 25 -
12 Appendix III: Self-diagnosis information...................................................................- 25 -
13 Recommended pH Electrodes for Other Specific Applications......................................- 26 -

- 4 -
1 Brief Introduction
Thank you for purchasing the Apera Instruments SX811-PW Portable pH Meter kit. This device is an
outstanding combination of advanced electrical, sensor technology and software design. The meter is
equipped with LabSen 803 pH Electrode, designed for testing pH levels of purified water such as drinking
water, RO water, distilled water, deionized water and other low ion-concentration liquid in an accurate
and convenient manner. It also works well testing regular water solutions.
(for other applications, please refer to Section 11 to find the most suitable electrode)
1.1 Features
•This microprocessor-based meter features automatic calibration, automatic temperature
compensation (ATC), menu set-up, calibration reminder, calibration date checking, automatic
powe-off and low-battery warning.
•GLP data management，clock display, manual storage and automatic timing storage, USB port
and power outage data protection, your data is safe even with a dead battery.
•Advanced digital processing technology improvs meter responding time and accuracy. 1-3 points
automatic calibration, calibration guide and self diagnose.
•IP57 waterproof, operable under extreme conditons. Powered by 3 AA batteries or USB
connection to other power source. Solid and durable case，accessories are included.
1.2 Features of the LabSen 803 Glass pH Electrode
•Proprietary pH sensor technology and materials from Switzerland
•Unique LabSen cylindrical glass membrane, faster response rate, better repeatability in purified
water
•Get stable pH readings in purified water or low ion-concentration solutions in 30 seconds on
average. Say goodbye to constant fluctuations
•Patented pH/Temperature combination structure (Swiss Patent Nr.699927), increasing the
temperature respond time by 40% compared to conventional isolated built-in thermistor
•Silver Ion Trap Reference System – On top of the Long-Life reference system, a silver ion trap is
added to prevent the junction being blocked by silver sulfide, having better stability and longer
service life.

- 5 -
1.3 Proper use and maintenance of the LabSen 803 Electrode
1.3.1 How to Use the Movable Sleeve
As shown on the right picture, reference solution flows out of the small
hole, seeps through the surface of movable sleeve. You may adjust
the degree of firmness when use. The looser the movable sleeve is,
the faster the reference solution’s flow speed is, meaning you will get
stabilized readings in a shorter time. Purified water and low ion
concentration solutions measurements require faster flow speed. The
electrode must be recalibrated after tightness adjustment.
To loosen the movable sleeve, push up the movable sleeve. If it is too
tight to push up, please refer to the right picture: insert the probe into the orange round tube (the
accessory comes with the probe), and press down the electrode with force, then the movable sleeve will
be loose. And then screw counter-clockwise to loosen the movable sleeve or clockwise to tighten it.
Please unplug the blue rubber plug on the refilling hole when adjusting the movable sleeve, this enables
the reference solution to flow out of the small hole; then slowly rotate and adjust the movable sleeve, so
that there will be no air remaining in the surface of the movable sleeve, which can greatly affect the correct
measurement.
1.3.2 Usage and Maintenance
a) Prior to measurement, remove the blue rubber plug to maintain proper air pressure of the reference
solution, keeping consistent flow rate of the reference solution and stable potentials of the junction.
Plug on the blue rubber plug after measurement.
b) After a period of usage, the reference solution will run low. Whenever the level falls to 1/2 height of the
electrode, add 3M KCL solution to the refilling hole with a syringe or pipette.
c) If reference solution is contaminated and needs replacement, unplug the blue rubber plug, loosen the
movable sleeve (see section 2), the reference solution will flow out quickly. Once the reference solution
runs out, use a syringe to add purified water through the refilling hole to rinse the electrode cavity; then
rinse again with 3M KCL to remove the remaining purified water; Tighten the movable sleeve, refill 3M
KCL solution with a syringe; then loosen the movable sleeve to let the solution flows out a bit, and
slowly twist it clockwise to tighten, so that air can be avoided in the surface of movable sleeve.
d) The connector of the electrode should be kept clean and dry. If contaminated, please clean it with
medical cotton and absolute alcohol and blow dry to prevent the short circuit of the electrode and slow

- 6 -
reaction of electrode.
e) The electrode’s measuring tip should be soaked in the storage bottle containing 3M KCL storage
solution to keep the membrane hydrated and junction unblocked. When measuring, please unscrew
the bottle cap, pull out the electrode and rinse it with deionized or distilled water. After using, please
put the electrode back into the bottle and screw tight the cap. Clean the bottle and replace the storage
solution if the storage solution gets turbid or mildewed. The electrode should never be soaked in
purified water or buffer solution for long.
f) NOTE: All the tests should be sample tests, meaning after measurement, the samples should be
abandoned and not be used for its original purpose again.
g) After 1-year of use, we recommend replacing the aged electrode to achieve the best accuracy.
2 Technical Specifications
2.1 Instrument Technical Specs
Technical Specs
pH
Range
-2.00 to 19.99 pH
Resolution
0.01/0.1 pH
Accuracy
±0.01 pH ±1 digit
Temperature
Compensation
0 to 100 ˚C (Auto or Manual)
mV
Range
-1999 mV - 0 - 1999 mV
Resolution
- 200 mV - 0 - 200 mV: 0.1 mV; Remaining: 1 mV
Accuracy
±0.1% F.S ±1 digit
Temp.
Range
0 to 100˚C (32 to 212˚F)
Resolution
0.1˚C
Accuracy
±0.5˚C ±1 digit
2.2 Others
Data Storage
500 groups
Storage Content
Numbering, date, time, measurement, unit, temperature
Output
USB
Power
AA Batteries * 3 / DC5V (USB port)
IP Ranking
IP57 dust-proof and waterproof
Dimensions& Weight
Meter: (88×170×33 ) mm/ 313g With case：(360×270×76) mm/ 1.6kg

- 7 -
2.3 Electrode Technical Specs
Housing Material
Lead-free Glass
Temperature sensor
NTC 30KΩ
Junction
Movable Sleeve
Reference Electrode
Silver Ion Trap
Electrolyte
3M KCL
Shape of glass membrane
Cylindrical
Range
0 to 11 pH
Temperature Range
0 to 80˚C (32 to 176˚F)
Connector
BNC and RCA
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 numbering for storage and recall, and prompts of
Diagram-1

- 8 -
special display mode
(10) — Storage and recall icons
M+ — Measurement to be stored icon, RM — Reading to be recalled icon
(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
3.2.1. Keypad operations
Short 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 setup mode, pressing is invalid. Please
press key to return to the measurement mode, then press to turn off the meter.
Diagram-2

- 9 -
Table – 1 Keypad operations and descriptions
Keypad
Operations
Descriptions
Short press
⚫Press this key to turn on or turn off the meter.
Short press
Select measurement parameters:
⚫pH meter: →
Long press
⚫In measurement mode, press this key to enter main menu.
Short press
⚫In measurement mode, press this key to enter in calibration mode
⚫In recall mode (RM), press this key to return to measurement mode
⚫Cancel any operation to return to measurement mode.
Short press
⚫In measurement mode, press this key to turn on or turn off backlight
⚫In calibration mode, press this key to conduct calibration
⚫In main menu, press this key to enter submenu
⚫In submenu, press this key to enter parameter set-up mode
⚫In parameter set-up mode, press this key to confirm parameters.
Long press
⚫In pH measurement mode, press and hold this key to change the
resolution repeatedly: 0.01→ 0.1pH
Short/
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 measurement mode, press to store the measuring value, press
to recall the stored measuring value
⚫In recall mode (RM), short press this key to change the storage
numberings, press and hold this key to change the number quickly
⚫In the main menu and submenu mode, press this key to change the
numbering of the main menu and the submenu
⚫In the parameter set-up mode, press this key to select parameters.

- 10 -
3.3 Display mode
3.3.1 Reading stability display mode
When the measuring value is stable, smiley icon appears on LCD,
see Diagram – 3. If icon does not appear or flash, please do not get
the reading value or make calibration until the measuring value is stable.
3.3.2 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 – 4. In the HOLD mode, press to release lock-up.
3.4 Data storage, recall, and delete
3.4.1 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 – 5: the meter stores the first group of the measuring value.
3.4.2 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 – 6: 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 not work. Set time 0 from
parameter P4.1 to exit from the automatic storage mode.
3.4.3 Recall stored data
In the measurement mode, press key to recall the last stored measuring
value. See Diagram – 7: 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.
3.4.4 Clear stored data
Select YES from parameter P4.5 to clear all stored value, refer to the Section 6.4.
Diagram - 3
Diagram - 5
Diagram - 7
Diagram - 4
Diagram - 6

- 11 -
4 pH Measurement
4.1 Information regarding pH Calibration
4.1.1 Things needed in addition to what’s included in the kit
A clean cup, distilled water (8-16oz), and tissue papers for rinsing and drying the probe.
4.1.2 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 1.3 regarding how to properly maintain the pH electrode.
4.1.3 Use the Electrode
Screw off the probe cap, and put it aside (do not dump or spill the 3M KCL solution). Prepare a 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). Unplug the blue rubber plug; insert the probe into the test sample, gently stir the
probe for a few seconds; wait for the stable reading (a smiley face appears and stays) and then record
the reading. When test is finished, plug on the blue rubber plug and rinse the probe with distilled water;
then place the electrode in the probe cap with 3M KCL solution and tighten the cap so as to keep the
sensitivity of the pH sensor.
NOTE: All the tests should be sample tests, meaning after measurement, the samples should be
abandoned and not be used for its original purpose again.
4.1.4 Standard Buffer Solution
The meter adopts 3 series of standard buffer solutions: USA, CH, and NIST. They can be selected in
parameter P1.1 (see Section 6.3) as showed in Table-2 (default standard series is USA)
Table-2
Calibration icon
pH standard buffer series
USA
CH
NIST
3-Point
calibration
1.68 or 4.00 pH
1.68 or 4.00 pH
1.68 or 4.01 pH
7.00 pH
6.86 pH
6.86 pH
10.01 pH
9.18 pH
9.18 pH

- 12 -
4.1.5 3-Point Calibration
The meter can adopt 1 to 3 points’ calibration. The 1st point must be using 7.00 pH (or 6.86 pH) buffer
solution, and then choose other buffers to do 2nd point and 3rd point. Please refer to Table-3 for details. In
the process of calibration, the slope of acidity range and alkalinity range will be displayed.
Table-3 Calibration Mode
CH
USA
NIS
Calibration
icon
When to adopt
1-Point
Calibration
6.86 pH
7.00 pH
6.86 pH
accuracy≤ ±0.1
pH
2-Point
Calibration
6.86 pH and
4.00/1.68 pH
7.00 pH and
4.00/1.68 pH
6.86 pH and
4.01/1.68 pH
0 to 7.00 pH
6.86 pH and 9.18
pH
7.00 pH and 10.01 pH
6.86 pH and 9.18 pH
7.00 to 14.00
pH
3-Point
Calibration
6.86pH, 4.00/
1.68 pH, and
9.18 pH
7.00pH, 4.00/
1.68 pH and 10.01 pH
6.86pH, 4.01/
1.68pH, 9.18 pH
0 to 14.00 pH
4.1.6 How often to calibrate
The frequency that you need to calibrate your meter depends on the tested samples, performace of
electrodes, and the requirement of the accuracy. For high-accuracy meaustements (≤ ±0.02pH), 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 before testing:
a) The electrode hasn’t been used for a long time or a new electrode is connected.
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 significant difference between the temperature of the test sample and the temperature of
the buffer solution that is used in the last calibration.
4.1.7 Calibration reminder
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
detailes, please see P1.2 (6.3). When the preset time is reached, Er6 icon will
be displayed at the lower right corner of the LCD (as showed in graph-8). At the
time, the meter can still be operated. It is just reminding you to do calibration in
order to ensure its accuracy. After calibration, the Er6 icon will disappear; To
make it disappear, users can also choose NO in P1.2 in parameter setting.
Diagram-8

- 13 -
4.1.8 Check calibration time
In this mode, users can see the date and time of last calibration so as to help them determine if there is
need to calibrate. For details, please see parameter setting P1.3 (Section 6.3)
4.1.9 Change temperature manually
When temperature electrode is not connected, long press or , the temperature will flash, and then
short press or long press or to change temperature, press to confirm.
4.2 pH Calibration
(use 3-point, USA Standard as an example)
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.
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).
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. 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 pH4.00 or pH10.01 buffer solution to make the 2nd
point calibration.
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, stable icon 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, CL3 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.
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
Diagram - 9

- 14 -
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–9 for the above
calibration process.
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.
4.3 Customized Calibration
(take 1.60pH and 6.50pH calibration solution as an example)
1) Select CUS from parameter P1.1 (please refer to Section 6.3 for customer-defined solution). The meter
enters into Customer-defined calibration mode. When press key, the meter’s display shows a blinking
CAL1 icon at the top right of LCD, indicating the meter enters into the 1st point customer-defined
calibration.
2) Rinse pH electrode in distilled 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.
3) Rinse pH electrode in distilled 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) 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 significant errors. The meter cannot
recognize customer-defined calibration solution automatically.

- 15 -
4.4 Sample test
1) Rinse pH electrode in distilled water, dry it, and dip it in sample solution. Stir the solution gently and let
it stand still 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 measurement
process of pH meter.
Diagram – 12 Calibration and measurement process of pH meter
2) pH measurement of purified water
The meter is able to set up pH measurement mode of purified water with
temperature compensation for pH value from parameter setup P1.5
(please see Section 6.3). “PU-1” icon displays at the right top of LCD,
please refer to Diagram – 10.
3) pH measurement of purified water mixed with ammonia
The meter is able to set up pH measurement mode of purified water mixed
With ammonia with temperature compensation for pH value from
parameter setup P1.6 (please see Section 6.3). “PU-2” icon displays at the
right top of LCD, please refer to Diagram – 11.
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) 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 - 10
Diagram - 11
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.
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 into the
measurement
mode.
After the 3rd point
calibration is done,
the meter enters
into the
measurement mode
Submerge the
electrode in pH4.00
solution, press
key when icon
appears.
Submerge the
electrode in
pH10.01
solution,press
key when icon
appears.

- 16 -
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 is
not stable during calibration.
Press key when icon appears.
During calibration, the measuring value
is not stable for ≥3min.
1.Check if the electrode is damaged.
2.The pH electrode is aged. Replace a new one.
pH electrode zero electric potential
out of range（<-60mV or >60mV）
1.Check whether pH buffer solution is correct.
2. Check if electrode is damaged.
3.The pH electrode is aged. Replace a new one.
pH electrode’s slope is 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.
5) pH isothermal 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.
*The electrode can only test samples that are below 176˚F. Testing higher-temperature samples
may cause permanent damage to the electrode.
6) Factory default setting
For factory default setting, please refer to parameter P1.6 (Section 6.3). 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.

- 17 -
5 mV measurement
5.1 ORP measurement
Press key, and switch the meter to mV measurement mode. Connect ORP electrode (sold 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
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.
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.
6 Parameter Setup
6.1 Main menu
In the measurement mode, press and hold key to enter in mode P1.0, then press or to switch
among main menu: P1.0→P2.0→P3.0→P4.0. Please refer to Diagram – 12.
P1.0: pH parameter setup menu,
P4.0: Basic parameter setup menu.
6.2 Submenu
1) In P1.0 mode, press key to enter in submenu P1.1 of pH parameter setup, then press
and key to switch among submenu: P1.1→P1.2→…→P1.6, refer to Diagram – 20.
2) In P4.0 mode, press key to enter in submenu P4.1 of basic parameter setup, then press
and key to switch among submenu: P4.1→P4.2→…→P4.8, refer to Diagram – 20

- 18 -
6.3 Submenu of pH parameter setup
(press or key to switch)
P1.1. – Select pH standard solution (USA-NIST-CUS-CH)
1. In P1.0 mode, press to enter in P1.1 mode, refer to the left diagram.
2. When press key, USA flashes,then press key, NIST flashes,etc.
When parameter flashes, press to make confirmation (USA – USA
series, NIS–NIST series, CUS–customer-defined, CH–Chinese series)
3. Press key to enter in P1.2 mode, or press key to return to the
measurement mode.
P1.1 Select pH standard solution series
P1.2 Set calibration due date
P1.3 Check date of last calibration
P1.4 Set pH measurement of purified water
P1.5 Set pH measurement of pure
water mixed with ammonia
P1.6 Restore to factory default setting
P4.1 Adjust timing storage time
P4.2 Select temperature unit
P4.3 Select backlight time
P4.4 Select auto. power-off time
P4.5 Clear stored value
P4.6 Set auto. lock-up function
P4.7 Adjust date
P4.8 Adjust time
Submenu of pH parameter setup
Submenu of basic parameter setup
Main menu of parameter setup
Diagram -12

- 19 -
P1.2. – Set due calibration (NO – H00 – D00)
1. When press key, No flashes, then press key, H flashes, then
press key, D flashes.
2. When H flashes, press key, 00 flashes. Press key to adjust hours
(0-99 hours), press key to confirm. When D flashes, press
key, 00 flashes. Press key to adjust days (0-99 days), press
key to confirm. When No flashes, press to confirm.
3. After confirming parameter, press key to enter in P1.3 mode, or press
key to return to the measurement mode.
P1.3. – Check the time and date of the last calibration
1. The time and date of calibration displays alternately at right top of LCD
(Date display: Month – Day), the number in the LCD middle displays
Year (Year 2012).
2. Press key to enter in P1.4 mode, or press key to return to the
measurement mode.
P1.4. – Set pH measurement of distilled water (Off – On)
1. Press key, Off flashes, then press key, On flashes, when
parameter flashes, press key to confirm. Off–turn off temperature
compensation, On – turn on temperature compensation.
2. After confirming parameter, press key to enter in P1.5 mode, or
press key to return to the measurement mode.
P1.5. – Set pH measurement of distilled water with ammonia (Off –
On)
1. Press key, Off flashes, then press key, On flashes, when
parameter flashes, press key to confirm. Off–turn off temperature
compensation, On–turn on temperature compensation.
2. After confirming parameter, press key to enter in P1.6 mode, press
key to return to the measurement mode.
P1.6. – Restore to factory default setting (NO – Yes)
1. Press key, No flashes, then press key, Yes flashes. Press
key to confirm, the meter returns to the measurement mode. No – Not
restore to factory default setting, Yes – restore to factory default setting.
2. When do not select Yes, press key to return to the measurement
mode.

- 20 -
6.4 Submenu of basic parameter setup
(press key or key to switch)
P4.1. – Adjust timing storage time
1. In mode P4.0, press key to enter in mode P4.1, refer to the left
diagram: “00:”: hours (0-99), “:00”: minutes (0-59).
2. Press key, “:00” flashes, then press key, “00:” flashes. When the
number flashes, press key and key to adjust time and press
key to confirm.
3. After confirming the parameter, press key to enter in P4.2 mode or
press key to return to the measurement mode.
P4.2. – Select temperature unit (°C—°F).
1. Press key, °C flashes, then press key, °F flashes. When the
parameter flashes, press key to confirm.
2. After confirming the parameter, press key to enter in P4.3 mode or
press key to return to the measurement mode.
P4.3. – Select backlight timing (1-2-3-On)
1. When press key, “1” flashes, then press key to select blinking
2→3→On. When the parameter flashes, press key to confirm.
Select On to turn on the backlight, the time unit is minute.
2. After confirming the parameter, press key to enter in P4.4 mode or
press key to return to the measurement mode.
P4.4. – Select automatic power-off time (10-20-30-On)
1. Press key, “20” flashes, then press key to select blinking
30→On→10. When the parameter flashes, press key to confirm.
Select On to turn on the function, the unit is day.
2. After confirming the parameter, press key to enter in P4.5 mode or
press key to return to the measurement mode.
P4.5. – Clear all the stored value
1. Press key, “No” flashes, then press key “Yes” flashes. When the
parameter flashes, press key to confirm. No: not delete, Yes:
delete.
2. After confirming the parameter, press to enter in P4.6 mode or
press key to return to the measurement mode.