Apera Instruments 950 Series User manual

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950 Series
Benchtop pH/Conductivity Meter
User Manual
PH950 Benchtop pH Meter
EC950 Benchtop Cond. Meter
PC950 Benchtop pH/Cond. Meter
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APERA INSTRUMENTS, LLC
aperainst.com

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Table of Contents
1 Introduction ................................................................................................................................... - 4 -
1.1 Measuring Parameters .......................................................................................................... - 4 -
1.2 Basic Features ....................................................................................................................... - 4 -
1.3 pH measurement features ..................................................................................................... - 4 -
1.4 Conductivity Measurement Features ..................................................................................... - 4 -
2 Configuration ................................................................................................................................. - 5 -
3 Specifications ................................................................................................................................ - 6 -
3.1 Technical Parameters ............................................................................................................ - 6 -
3.2 Other Technical Parameters .................................................................................................. - 6 -
4 Instrument Description .................................................................................................................. - 7 -
4.1 LCD Display ........................................................................................................................... - 7 -
4.2 Keypad functions ................................................................................................................... - 8 -
4.3 Meter Sockets ...................................................................................................................... - 10 -
4.4 Display Mode ........................................................................................................................ - 11 -
4.5 Data Storage, Recall and Delete .......................................................................................... - 11 -
4.6 Manually adjust temperature ............................................................................................... - 12 -
4.7 Install Meter with Multi-function Test Bench ......................................................................... - 13 -
4.8 Installation of Flexible Electrode Holder .............................................................................. - 13 -
4.9 Mulit-function Test Bench ..................................................................................................... - 13 -
5 pH Measurement ........................................................................................................................ - 14 -
5.1 Default Electrodes Information ............................................................................................ - 14 -
5.2 pH Calibration Related Information ...................................................................................... - 16 -
5.3 pH meter calibration (take three-point calibration as an example) ...................................... - 18 -
5.4 User-defined calibration (take pH 2.00 and pH 7.30 calibration solution as an example) ... - 19 -
5.5 Self-diagnosis Information ................................................................................................... - 21 -
5.6 Sample measurement .......................................................................................................... - 22 -
6 mV Measurement ........................................................................................................................ - 23 -
6.1 ORP measurement .............................................................................................................. - 23 -
6.2 Notes for ORP measurement ............................................................................................... - 23 -
6.3 Ion Selective Potential Measurement .................................................................................. - 23 -
7 Conductivity Measurement ......................................................................................................... - 24 -
7.1 Conductivity electrode information ....................................................................................... - 24 -
7.2 Conductivity calibration related information ......................................................................... - 24 -

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7.3 Conductivity meter calibration (take 1413μS/cm calibration as an example) ...................... - 26 -
7.4 User-defined calibration (take 10μS/cm standard solution as an example) ......................... - 27 -
7.5 Self-diagnosis information ................................................................................................... - 28 -
7.6 Solution measurement ......................................................................................................... - 29 -
7.7 Conductivity electrode maintenance .................................................................................... - 30 -
8 Parameter setting ........................................................................................................................ - 31 -
8.1 Main menu and submenu .................................................................................................... - 31 -
8.2 Operation ............................................................................................................................. - 32 -
8.3 Content of parameter setting ............................................................................................... - 32 -
9 Stirrer .......................................................................................................................................... - 33 -
9.1 Operation ............................................................................................................................. - 33 -
9.2 Specification ........................................................................................................................ - 33 -
9.3 Notes ................................................................................................................................... - 33 -
10 USB communication ................................................................................................................ - 34 -
10.1 Install Software .................................................................................................................... - 34 -
10.2 Software Interface ................................................................................................................ - 34 -
10.3 Operation Keys of PC-Link .................................................................................................. - 34 -
11 Recommended pH Electrodes for Specific Applications ......................................................... - 35 -
12 Recommended Conductivity Electrodes for Specific Applications .......................................... - 35 -
13 Warranty .................................................................................................................................. - 36 -
Notes
• When the meter is connected to PC, do not pull out the USB cable until the
meter is turned off. Otherwise a system crash could occur. To fix the crash, pull
out the power cord, put it back in, and reboot the meter.
• Please do NOT pull out the power cord when the meter is turned on.

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1 Introduction
Thank you for purchasing the 950 Series Benchtop pH/Cond. Meter.
Before using this meter, please read this manual carefully to help you use and maintain it properly.
1.1 Measuring Parameters
Parameter and configuration!
PH950
EC950
PC950
pH/mV
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Conductivity/TDS/Salinity
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Temperature
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Electrode Stand
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1.2 Basic Features
l Clear TFT color display
l User-friendly operating system with graphics and texts
l Multi-language operating system (English, German, Spanish & Chinese)
l The smiling icon indicates the reading stability, including automatic lock function.
l With built-in microprocessor chip, the meter has intelligent functions such as automatic calibration,
automatic temperature compensation, function setting, self-diagnosis, and data logger.
l PC950 meter can measure and display pH & conductivity readings simultaneously.
l Meter can configure with 606 multifunction test bench which is combined by intelligent stirrer and
flexible electrode holder. It can hold solution bottles, electrodes and stirrer beads. Stepless speed
regulation intelligent stirrer, it can also store rotation speed.
1.3 pH measurement features
l 1–3 point automatic calibration with calibration instruction and automatic check functions.
l Automatically recognize pH buffer solution. 3 series buffer solution selectable: USA series, NIST
series and China series, as well as user-defined solutions.
l Automatically display electrode slope.
1.4 Conductivity Measurement Features
l 1– 4 point automatic calibration with calibration instruction and automatic checking functions.
l Automatically recognize conductivity standard solution. 2 series standard solution selectable: USA
and CH, as well as user-defined solution.
l Single-tap switch among conductivity, TDS, and salinity.

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2 Configuration
Description
Quantity!
PH950
EC950
PC950
2.1
PH950 pH meter
1
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2.2
EC950 conductivity meter
1
!
2.3
PC950 pH/conductivity meter
1
!
2.4
606 multi-function stirrer (includes flexible
electrode holder)
1
!
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!
2.5
LabSen211 glass pH combination electrode
1
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!
2.6
MP500 temperature probe
1
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"
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2.7
2401T-F conductivity electrode (ATC, K=1.0)
1
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2.8
pH buffer solution (4.00/7.00/10.01pH/50mL)
1 bottle
each
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2.9
Conductivity standard solution
(84μS/1413μS/12.88mS/50mL)
1 bottle
each
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2.10
Stirrer connection cable
1
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2.11
PCLink-950 Flash Disk
1
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2.12
USB communication cable
1
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2.13
9V power adapter
1
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2.14
Instruction manual
1
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2.15
Quick manual
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3 Specifications
3.1 Technical Parameters
Technical Parameters
Model
pH
Measuring Range
pH 0.00 – 14.00
PH950
PC950
Resolution
0.1/0.01 pH
Accuracy
± 0.01 pH ± 1 digit
Temp. Compensation
Range
32 – 212 ˚F (0 – 100) ˚C (Auto. or Manual)
Calibration point
1 – 3 points
mV
Measuring Range
± 2000 mV
Resolution
1 mV
Accuracy
± 0.1% FS ± 1 digit
Cond.
Measuring Range
Conductivity"0 – 200 mS/cm, divided into five ranges,
automatically switch measuring range.
(0 – 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
EC950
PC950
Resolution
0.01/0.1/1μS/cm 0.01/0.1 mS/cm
Accuracy
± 1.0% FS ± 1 digit
Temp. Compensation
Range
32–122 ˚F (0 – 50) ˚C (Auto. or Manual)
Cell constant
0.1 / 1 / 10 cm-1
Temp.
Measuring Range
32 – 212 ˚F (0 – 100 ˚C)
PH950
EC950
PC950
Resolution
0.1 ˚F (0.1 ˚C)
Accuracy
± 0.9 ˚F (± 0.5 ˚C) ±1 digit
3.2 Other Technical Parameters
Data Storage
200 groups
Storage Content
Number, date, time, measuring value and temperature value
Power
DC9V/600mA
Dimension & Weight
Meter"(195×215×100) mm / 0.9kg

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4 Instrument Description
4.1 LCD Display
#$pH measurement
%$pH measuring value and unit
&$Temp e r a t u r e m e a suring value
'$pH electrode slope
($Calibration solution indication icon
)$Used data storage
*$Temp e r a t u r e c o m pensation icon,
MTC-manual temperature compensation
ATC-auto. temperature compensation
+$Auto. Hold
,$Stable reading icon
-$Date and time
.
11 $Auto. data log
.
12 $Storage icon and number
.13$Stirrer icon
#$Conductivity measurement
%$Conductivity measuring value and unit
&$Temp e r a t u r e m e a suring value
'$Conductivity parameter:
25.0 ˚C$reference temperature
2.00%$temperature compensation
($Calibration solution indication icon
)$Used data storage
*$Temp e r a t u r e c o m pensation icon,
MTC-manual temperature compensation
ATC-auto. temperature compensation
+$Auto. Hold
,$Stable reading icon
-$Date and time
.
11 $Auto. data log
.
12 $Storage icon and number
.13$Stirrer icon
Conductivity measurement interface
pH measurement interface

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4.2 Keypad functions
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Keypad operation mode
Short press—Press key <2s, buzzer makes a beep;
Long press—Press key >2s, buzzer makes a beep.
Diagram-1
#$TDS measurement $$TDS factor 0.71
mV measurement interface
pH/Cond. measurement interface
TDS measurement interface
Salinity factor 0.5
Salinity measurement interface

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Table -1 Keypad operations and functions
Keypad
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Operations
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Functions
!
Short press!!
l Power on/off!
Short press!
Press key to select measurement mode:
l PH950: pH→mV
l EC950: Cond→TDS→Salt
l PC950: pH→mV→Cond→TDS→Salt→pH/Cond
Long press
l Press key to enter temperature adjustment mode
(for manual temperature
compensation)
Long press
l In measurement mode, press key to enter calibration mode
Short press
l Cancel operation and return to measurement mode;
Short press
l In measurement mode: press key to enter parameter setup main menu;
l In calibration mode: press key to conduct calibration;
l In main menu mode: press key to enter submenu;
l In submenu mode: press key to enter parameter setup;
l In parameter setup mode: press key to confirm parameter change;
l In temperature adjustment mode: press key to confirm temperature value.
Short press
l In measurement mode: press key to save measurement data,
press key to recall the saved data;
l In recall (RM) mode: press or key to turn page;
l In menu mode: press key to select items;
l In temperature adjustment mode:
press key to change temperature value,
hold key for fast change.

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4.3 Meter Sockets
Model
Meter sockets
PH950
① ② ③ ⑥⑦
EC950
④ ⑤ ⑥⑦
PC950
① ② ③ ④ ⑤ ⑥⑦
Meter Sockets Information
Socket Type
Information
①
BNC
Connect pH or ORP combination electrode
②
RCA
Connect temperature sensor (for pH)
#+$
BNC+RCA
connect pH/ATC 3-in-1 combination electrode
③
Ф4 banana
Connect reference electrode
④
BNC
Connect conductivity electrode
⑤
RCA
Connect temperature sensor (for conductivity)
%+&
BNC+RCA
connect with Cond/ATC electrode
⑥
USB
Connect PC
⑦
Ф2.5 power supply
Connect DC9V adaptor (inside “'” outside “−”)
Diagram-2

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4.4 Display Mode
4.4.1 Reading stable display mode
When the measuring value is stable, smiley icon
appears and stays on LCD screen, see Diagram – 3.
If the smiley icon does not appear or flash, please do
not get readings or make calibration until the measuring
value is stable.
4.4.2 Auto. lock on display mode
In parameter setting 3.1, set “Reading with HOLD” to “ON”, when icon stably display for more than
10 seconds, the meter will lock the value automatically and display HOLD icon, see Diagram – 4(b). In
HOLD mode, press key to cancel auto lock.
4.5 Data Storage, Recall and Delete
4.5.1 Storage
(a) Manual data logger
Set “auto. timing” to “00:00:00”, Press key to store, icon 6 displays on the down right corner
of LCD screen which means it’s the 6th group data, see Diagram – 5(a); Each meter can store 200 groups
data. For single parameter display mode, 1 serial number corresponds to 1 group measuring vale. For
dual parameter display mode (means pH + Cond. meter display mode), 1 serial number corresponds to
2 groups measuring value (pH + conductivity). So for this type of meter, actual store data is 200 groups,
but storage number will be less than 200. If press key again when storage value is full, icon will
flash, see Diagram –5(c) to indicate store memory is already full and need to be deleted for new store
value.
(b) Auto. timing data logger
Select “Timer” in parameter setting 3.2 and set the data logging interval time (by every X seconds or
minutes), for example, 3 minutes. In auto timing data logo mode, shows up, press to start
auto. data logger, flashes, the first set of measurement data is stored, then every three minutes
Diagram-3
(a)
(b)
Diagram-4
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one set of data will be stored and the storage number will be automatically increased. Press again
to stop auto. data logger. In this mode, the manual data logging is invalid.
4.5.2 Data recall
Press key, meter will display stored 6 groups measuring value, see Diagram – 5(b), press
or key to turn page. Every page displays 8 groups of data.
4.5.3 Delete
Data need to be deleted when storage memory is full, otherwise no more data can be stored. In parameter
setting 3.4 select “Yes” and press key, see Diagram – 5(d) to delete all stored value. Note: when
connect the meter via USB cable to store the measured values to the computer, there is no
limitation on the number of data storage, either manual or automatic storage.
4.6 Manually adjust temperature
When no temperature probe is connected, long press key to enter MTC mode. Press or
key to adjust temperature value. Press and hold the key for fast adjustment. Press key to
confirm and return to measurement mode.
Diagram-5
(a)
(b)
(c)
(d)

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4.7 Install Meter with Multi-function Test Bench
Before installing
After installing
4.8 Installation of Flexible Electrode Holder
4.9 Multi-function Test Bench
a) Combo mode (b) Separate use (maximum distance 35cm)
Meter
Mulit-function test bench
Stirrer connection cable
Connection bar
Aim hole to shaft
and press down

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5 pH Measurement
5.1 Default Electrodes Information
The meter comes with a LabSen 211 pH combination electrode and MP500 temperature probe, which
enables the automatic temperature compensation. The LabSen pH electrodes are made with
proprietary sensor technologies and premium materials from Switzerland. LabSen 211 pH electrode is
designed for high-precision lab and field pH measurement of general water solutions. The electrode is
compatible with TRIS buffers.
For testing pH of special samples such as viscous (sticky), strong acidic or alkaline solutions, solutions
at high or low temperature (>50˚C or <10˚C), solid samples, turbid solutions, low ion-concentration
solutions & etc…specialized pH electrodes are necessary in order to achieve reliable results. Regular
pH electrodes in these special applications usually would generate inaccurate and unstable
measurements, and may be damaged by the samples, or even be non-applicable for testing at all.
Please refer to Section 10 for ideal pH electrodes to use for other applications.
5.1.1 Features of LabSen 211 pH Electrode
l Built with LabSen S-type hemispherical glass membrane, featuring low resistance (fast response)
and high firmness
l No more air bubbles inside the glass membrane thanks to the Swiss blue gel electrolyte.
l The long-life reference system significantly increases measuring stability and extends service life.
5.1.2 Technical Specifications of the LabSen211 pH Electrode
Measuring Range
0-14 pH
Temperature Ra n g e
23 to 212 ˚F (-5 to 100 °C)
Membrane Types
S
Body Material
Lead-free Glass
Reference
Long Life
Junction
Ceramic
Reference Solution
3M KCL
Soaking Solution
3M KCL
Membrane Resistance
<150 MΩ
Electrode Dimension
(Φ12×120) mm
Connector and cable length
BNC/1m
5.1.3 Technical Specifications of the MP500 Temperature Probe
Temperature Ra n g e
14 to 230 ˚F (-10 to 110 °C)
Body Material
Stainless Steel
Sensor
30 KΩ thermistor
Probe Dimension
(Φ5×145) mm
Connector
RCA
Connector and cable length
BNC/1m

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5.1.4 How to use
1. Insert the blue BNC connector of the electrode to the BNC socket of your
pH meter while twisting clockwise until it`s locked, plug the RCA
connector into the “TEMP” sockets. Please note not to pull the cables in
case of poor contact. Please keep the connectors clean and dry.
2. Before measuring, twist off the storage bottle cap (see graph on the
right), pull out the electrode and rinse it off with distilled or deionized
water.
3. Unplug the blue rubber plug to maintain a smooth electrolyte flow.
4. Stir the solution briefly to eliminate the air bubbles and in this way, a
stable measurement will be reached fast.
5. Perform at least a two-point calibration before measuring after connecting the new electrode to
your pH meter.
6. After using, put the electrode back into the storage bottle, twist on the bottle cap, and plug in the
refilling hole.
5.1.5 Maintenance
1. When not in use, the electrode should be soaked in the storage bottle containing 3M KCL soaking
solution (SKU: AI1107) to keep the glass membrane and junction in a healthy condition. Clean the
bottle and replace the soaking solution if it gets contaminated. The electrode should never be
stored in pure water such as deionized or distilled water.
2. The reference solution will run low as you use the electrode. Whenever the solution level falls to
1/2 height of the electrode, add 3M KCL solution (SKU: AI1107) to the refilling hole (unplug the blue
rubber plug) using a syringe or pipette.
3. The electrode is only as accurate as it is clean. Always thoroughly rinse off the electrode before
and after each measurement with pure water in a container or with a wash bottle.
4. For tough contaminants, soak the electrode in Apera cleaning solution (AI1166) for 30 minutes.
Then use a soft brush to remove the contaminants. Afterwards, soak the electrode in 3M KCL
solution (SKU: AI1107) for at least 1 hour. Rinse it off, then re-calibrate it before using again.
5. The connector of the electrode should be kept clean and dry. If contaminated, please clean it with
medical cotton and isopropyl alcohol and blow-dry it to prevent short circuit of the electrode or slow
response of the electrode.
6. The electrode should avoid testing strong acid and strong alkali solutions, as well as dehydrating
media such as absolute ethanol and concentrated sulfuric acid. If testing such solutions, the
immersion time should be minimized and the electrode should be carefully cleaned after use.
7. Every pH electrode will eventually age and fail. The typical service life of Apera pH electrodes is 12
to 24 months depending on the frequency of usage and how well you keep it clean and properly
stored. We recommend replacing your electrode every 12-18 months to ensure the best
performance.

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5.2 pH Calibration Related Information
5.2.1 Standard buffer solution
The instrument adopts three series standard buffer solution, USA, NIST and CH series, and also user-
defined solution. Please see Table – 2 for the three series of standard buffer solution. The detail of user-
defined solution, see clause 5.4.
Table -2 pH standard buffer solution series
Calibration indication icons
pH standard buffer solution series
USA series
NIST series
CH series
Three-point
calibration
or
pH 4.00 or 1.68
pH 4.01 or 1.68
pH 4.00 or 1.68
pH 7.00
pH 6.86
pH 6.86
or
pH 10.01 or 12.45
pH 9.18 or 12.46
pH 9.18 or 12.46
Note: calibration indication icons are example of USA series.
5.2.2 Three-point calibration
The instrument can perform 1(3 point calibration. In three-point calibration mode, the first point
calibration must use pH 7.00 (or pH 6.86) standard solution, then select other standard solution to perform
the second and the third point calibration. See Ta b l e – 3. Users can choose two-point calibration of pH
7.00 and pH 1.68 for strong acidic solutions (<pH 2), or pH 7.00 and pH 12.45 for strong alkaline solutions
(>pH 12).
Table -3 Three-point calibration mode
USA standard
NIST standard
CH standard
Applicable
range
One-point
calibration
pH 7.00
pH 6.86
pH 6.86
Accuracy
≤± 0.1pH
Two-point
calibration
pH 7.00 and
pH 4.00/1.68
pH 6.86 and
pH 4.01/1.68
pH 6.86 and
pH 4.00/1.68
< pH 7.00
pH 7.00
and pH
10.01/12.45
pH 6.86 and
pH 9.18/12.46
pH 6.86 and
pH 9.18/12.46
> pH 7.00
Three-
point
calibration
pH 7.00,
pH
4.00/1.68 and
pH 10.01/12.45
pH 6.86,
pH 4.01/1.68 and
pH 9.18/12.46
pH 6.86,
pH 4.00/1.68 and
pH 9.18/12.46
pH 0 – 14.00

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5.2.3 Calibration information display
1. Automatically display electrode slope in measurement
interface
l Display average slope after two or three point calibration
l Does not display slope after one point calibration
2. Display last calibration data in pH submenu clause 1.3
5.2.4 Calibration frequency
The frequency that you need to calibrate your meter depends on the tested samples, condition of
electrodes, and the requirement of the accuracy. For high-Accuracy measurements (≤ ±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:
a) The electrode hasn’t been used for a long time or a new electrode is connected.
b) After measuring strong acidic (pH<2) or strong alkalis (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.
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5.3 pH meter calibration (take three-point calibration as an example)
Long press key to enter calibration mode, as shown in
left graph. Rinse pH electrode in purified water, remove excess
water by shaking or filter paper. Press key to confirm.
Submerge electrode in pH7.00 buffer solution. Stir the solution
briefly and allow it to stay in the buffer solution until
appears and stays. Press key to finish calibration.
Rinse pH electrode in purified water, allow it to dry by shaking
or filter paper. Press key to confirm. If only need one
point calibration, press key to return to measurement
mode.
Submerge electrode in pH4.00 buffer solution. Stir the solution
briefly and allow it to stay in the buffer solution until
appears and stays. Press key to finish calibration.
Rinse pH electrode in purified water, remove excess water by
shaking or filter paper. Press key to confirm. If only
need two-point calibration, press key to return to
measurement mode.

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Submerge electrode in pH10.01 buffer solution. Stir the
solution briefly and allow it to stay in the buffer solution until
appears and stays. Press key to finish calibration.
Calibration completed, instrument goes back to measurement
mode.
5.4 User-defined calibration (take pH 2.00 and pH 7.30 calibration solution
as an example)
1. Select User in parameter setting 1.1, press key to
return to measurement mode.
2. Long press key to enter calibration mode, as shown in
left graph. Rinse pH electrode in purified water, remove
excess water by shaking or filter paper. Press key to
confirm.
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3. Submerge electrode in pH2.00 buffer solution. Stir the
solution briefly and allow it to stay in the buffer solution until
appears and stays. Press or key to
adjust the value to 2.00 pH. Press key to finish
calibration.
4. Rinse pH electrode in purified water, remove excess water
by shaking or filter paper. Press key to confirm. If
only need one point calibration, press key to
return to measurement mode.
5. Submerge electrode in pH7.30 buffer solution. Stir the
solution briefly and allow it to stay in the buffer solution until
appears and stays. Press or key to
adjust the value to 7.30 pH. Press key to finish
calibration.
6. Calibration completed, instrument goes back to
measurement mode.
Notes
(a) The meter can perform 1-2 point user-defined calibration. When the 1st point calibration is done,
press key, the meter exits from calibration mode. This is one-point user-defined calibration.
(b) The meter does not have the function to recognize user-defined calibration solution. But it requires
the error of user-defined calibration solution ≤1pH, the difference between two calibration solution
≥1pH, otherwise the meter will display self-diagnostic error.
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