XS Instruments pH 70 Plus User manual

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Index
Introduction.............................................................................................................................................................4
Measurement parameters.......................................................................................................................................4
Basic features...........................................................................................................................................................4
pH measurement features (suited for model pH70+DHS and PC70+DHS) ..............................................................4
Conductivity measurement features (suited for model COND70+ and PC70+DHS) ................................................4
Data sheet................................................................................................................................................................5
Instrument Description............................................................................................................................................6
LCD Display ..............................................................................................................................................................6
Keypad Functions.....................................................................................................................................................6
Meter Connections ..................................................................................................................................................7
Stability indication ...................................................................................................................................................8
Parameter selection.................................................................................................................................................8
Automatic Power Off ...............................................................................................................................................8
DHS Technology .......................................................................................................................................................8
pH Measurement.....................................................................................................................................................9
pH electrode information ........................................................................................................................................9
pH calibration consideration - Standard buffer solution..........................................................................................9
Three-point calibration ............................................................................................................................................9
Calibration Intervals.................................................................................................................................................9
Due calibration.......................................................................................................................................................10
Check calibration date ...........................................................................................................................................10
pH Meter Calibration .............................................................................................................................................10
Customer calibration .............................................................................................................................................11
Measurement ........................................................................................................................................................12
Factory default setting ...........................................................................................................................................12
Self-diagnosis information .....................................................................................................................................13
pH electrode maintenance ....................................................................................................................................13
Daily maintenance .................................................................................................................................................13
Calibration buffer solution.....................................................................................................................................13
Protect glass bulb...................................................................................................................................................13
Regenerate glass bulb............................................................................................................................................13
mV measurement ..................................................................................................................................................14
ORP ........................................................................................................................................................................14
Clean and activate ORP electrode..........................................................................................................................14
Conductivity...........................................................................................................................................................14
Conductivity cell ....................................................................................................................................................14
Conductivity cell constant......................................................................................................................................14
Conductivity calibration solutions .........................................................................................................................15
Calibration intervals...............................................................................................................................................15
1-point and multi-point calibration .......................................................................................................................15
Reference temperature..........................................................................................................................................15

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Temperature coefficient.........................................................................................................................................15
Avoid contamination of standard solution ............................................................................................................16
Due calibration.......................................................................................................................................................16
Check the calibration date .....................................................................................................................................16
Conductivity Calibration ........................................................................................................................................16
Customer calibration .............................................................................................................................................17
Measure.................................................................................................................................................................18
Factory default setting ...........................................................................................................................................18
Conductivity electrode maintenance.....................................................................................................................18
Relations between TDS, Salinity and conductivity.................................................................................................18
Datalogger functions (pH70+DHS, COND70+, PC70+DHS).....................................................................................19
Manual storage......................................................................................................................................................19
Automatic timing storage ......................................................................................................................................19
Recall stored value.................................................................................................................................................19
Clear stored value ..................................................................................................................................................19
Setup Menu ...........................................................................................................................................................20
Main menu.............................................................................................................................................................20
Submenu................................................................................................................................................................20
Connection to PC and DataLink70 v1.4 software (pH70+DHS, COND70+, PC70+DHS)..........................................22
USB connection......................................................................................................................................................22
Software interface .................................................................................................................................................22
Appendix I: Parameter setting & Factory default setting.......................................................................................23
Appendix II: Self-diagnosis information .................................................................................................................24

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Introduction
Thanks for purchasing 70+ series portable pH/Conductivity meter.
This meter is perfect combination of the most advanced electronics, sensor technology and software
design, and is the most cost effective portable electrochemical meter suited for industrial and mining
enterprises, power plant, water treatment engineering, environmental protection industry, etc,
especially suited for application in field.
In order to use and maintain the instrument properly, please read the manual thoroughly before use.
To improve instrument performance constantly, we reserve the right to change the manual and
accessories without giving notice in advance.
Measurement parameters
Measurement parameters
pH70+DHS
COND70+
PC70+DHS
pH/mV
√
√
Conductivity/TDS/Salinity
√
√
Temperature
√
√
√
Basic features
• 3 Colors display for intuitive operations
•The microprocessor-based portable meter features automatic calibration, automatic
temperature compensation, function set-up, self-diagnostics, automatic power-off and low
voltage display.
•The meter’s digital filter improves measurement speed and accuracy. There is reading stability
display.
•The package includes portable case, meter, electrode, standard solutions and all accessories,
convenient to use in field.
•The meter is dust-proof and water-proof, meeting the IP57 rating.
•Temperature calibration function.
•Selection of parameters to be display (only for PC70+DHS)
•Meet GLP, clock display, manual storage and automatic timing storage, USB port for PC linking
and power supply
pH measurement features (suited for model pH70+DHS and PC70+DHS)
•1-3 point automatic calibration, the meter provides calibration guide and automatic checking
function.
•The meter is able to recognize up to 8 types of pH standard buffer solutions. There are three
options of standard buffer solution: USA series, NIST series and customer solution set-up.
•The meter recognize DHS Sensor
Conductivity measurement features (suited for model COND70+ and PC70+DHS)
•1-4 point automatic calibration, the meter provides calibration guide and automatic checking
function.
•The meter is able to recognize up to 4 types of conductivity standard solutions. There is
customer-defined solution set-up.
•TDS and salinity measurement

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Data sheet
Specifications
Models
pH
Range
（-2.00 ~ 16.00）pH
pH 70+
PC 70+
Resolution
0.1/0.01 pH
Accuracy
±0.01 pH ±1digit
Temperature
compensation
（0 ~ 100）°C（manual or automatic）
Multi-point
calibration
1-3 point
Buffer value
USA: 1,68 - 4,00 - 7,00 - 10,01pH
NIST: 1,68 - 4,01 - 6,86 - 9,18pH
2 value CUSTOMER
mV
Range
+1900mV – 1000mV
Resolution
0.1mV (+200mV) / 1mV (other values)
Conductivity
Range
Conductivity: 0~200 mS/cm(divided into four ranges):
（0~199.9）μS/cm ; (200~1999) μS/cm ;
（2.00~19.99）mS/cm; （20.0~199.9）mS/cm
C0ND 70+
PC 70+
Resolution
0.01/0.1/1μS/cm 0.01/0.1 mS/cm
Accuracy
±2.0% FS
Temperature
compensation
（0 ~ 100）℃（manual or automatic）
Electrode constant
0.1 / 1 / 10 cm-1
Multi-point
calibration
1-4 point
Standard solution
84 μS/cm, 1413 μS/cm, 12.88, 111,9 mS/cm
1 customer value
TDS
Range
0~100 g/L
Resolution
1% f.s.
Salinity
Range
0~50 g/L
Temperature
Range
-10~110°C
pH 70+
C0ND 70+
PC 70+
Resolution
0.1℃
Accuracy
±0.5℃±1digit
Power
AA batteries × 3 (1.5V× 3) / AC/DC adapter with USB
IP rating
IP57
Dimension & Weight
Meter: (86×196×33) mm / 295g
Data Storage
500 slots

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Instrument Description
LCD Display
The instrument is provided with three-color backlit display to help the user get a quick and intuitive
understanding of how to use them
•Green: Measurement and setup mode
•Blue: Calibration mode
•Red: Alarm/Error
(1) — Parameter icons
(2) — Measurement reading
(3) — Automatic data storage mode
(4) — Time (appears with (5), and prompts of special
display mode)
(5) — Date (appears with (4))
(6) — Units of measurement
(7) — Temperature units (°C and °F)
(8) — Units of pH and conductivity calibration value
(appears with(9))
(9) — pH and conductivity calibration value or store
position (RM)
(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) — Temperature compensation icons
ATC — automatic temperature compensation, MTC — manual temperature compensation
(13) — Calibration range icon
(14) — USB icon，when this icon appears, the meter connects the computer
(15) — Stability icon
(16) — Battery life
Keypad Functions
Momentary press ----- <1.5 seconds
Long press ----- >1.5 seconds
Turn on the meter
Press to turn on the meter: LCD full display → display
colors RGB test with some parameters → display the last
measurement mode.
Turn off the meter
In the measurement mode, press and hold for 2 seconds
to turn off the meter.
Note: In the calibration mode or the parameter set-up mode, press for return to the measurement mode, then press
to turn off the meter.
SAL

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Keypad
Operations
Descriptions
Momentary press
•In the power-off mode, press this key to turn on the meter
•In the measurement mode, press this key to turn on or turn off the backlight
display
Long press
In the measurement mode, press and hold this key for 2 seconds to turn off the meter
Momentary press
•pH70+DHS: press this key to select measurement mode: pH → mV,
•COND70+: press this key to select measurement mode:
COND → TDS → SAL
•PC70+DHS: press this key to select measurement mode:
pH → mV → COND → TDS → SAL
Momentary press
•In the measurement mode, press this key to enter in the calibration mode
•In the calibration mode or the setup mode, press this key to return in
measurement mode
•In the recall mode (RM), press this key to return to the measurement mode
Momentary press
•In the measurement mode, press this key to enter in the parameter set-up
main menu
•In the calibration mode, press this key to confirm calibration
•In the parameter set-up mode, press this key to select programs
Long press
•In the mode of manual temperature compensation (MTC), when press and
hold these keys, the temperature value flashes, then press this keys to
change the temperature value, and press to confirm
Momentary press
•In the recall mode (RM), press momentarily this kesy to change the storage
serial number, press and hold this key to change the number quickly
•In the setup mode, press this key to scroll menu and submenu
•In the submenu mode, press this key to change parameters and values
•In the measurement mode, press key to store manually the value
•In the measurement mode, press key to recall the stored measuring
value
Meter Connections
Models
Photos
Description
pH70+DHS
•BNC socket— pH electrode or ORP electrode
•RCA socket —temperature probe
COND70+
•BNC socket— conductivity electrode,
•RCA socket — temperature probe
PC70+DHS
•BNC socket —pH electrode or ORP electrode,
•BNC socket— conductivity electrode,
•RCA socket— temperature probe

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Stability indication
When the measuring value is stable, smiley icon appears on LCD.
If the smiley icon does not appear or flash, please do not get the reading value, or make calibration until the
measuring value is stable.
In the parameter P1.6, there are 3 criteria for stability standard:
-Normal (default) -High (longer time) -Low (shorter time.)
User can select suitable stability criteria according to different testing requirement.
Parameter selection
Only for PC70+DHS, enter in the setup menu P6.6, one by one the parameters blinks on the top left of the LCD;
press and keys for choose Yes (parameter enabled) or No (parameter disable) .Then press key to
confirm. Press key to return in measurement mode.
Automatic Power Off
If the meter stops operation for 20 minutes, It will turn off automatically. In the setup menu P6.8 the
user has the possibility to disable this option. In the automatic storage mode, the automatic power off is not
possible.
DHS Technology
DHS technology, developed by Giorgio Bormac company, allows to save calibration data inside the memory of
the pH electrode.
It is possible to calibrate the XS DHS electrode in laboratory, in ideal conditions, using a XS DHS meter.
Calibration data, like date, slope, model and batch number, are memorized inside the electrode.
Moving this electrode on another XS meter DHS compatible, the electrode is ready for high quality
measurement, extremely safety and without a new calibration.
Simply useful: XS Meters DHS compatible recognize automatically If a XS sensor DHS is connected.
If not, the instrument will work as a standard pH meter.
And the same is for the electrode: Is possible to connect a XS sensor DHS on a standard XS meter (NO DHS
compatible) It will work as a standard pH electrode.
XS DHS sensors use just a BNC plug for the pH, and a RCA/Cinch plug for the temperature, exactly the same
connectors of the standard XS electrodes.
And It hasn’t the battery, so It is possible to stock the electrode as normal one.
After connecting the XS electrode DHS, meter will recognize It automatically, and display sequentially:
To calibrate the DHS sensor follow the calibration procedure at page 10 (pH meter calibration).
When the DHS electrode is disconnected, display shows:
Note: DHS activation and disabling occur only in measurement mode.
sensor model
Batch number
pH
No
dhs
Calibration points
dhs
pH
pH
year
Slope
100
%
Month
day
Date of the last calibration

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pH Measurement
pH electrode information
On this meter is possible to use electrode with integrated temperature sensor else link two different probes for
pH and temperature.
The BNC socket of electrode connects pH socket, RCA socket connects temperature socket. When dip the
electrode in the solution, please stir the solution briefly and allow it to stay in the solution until a stable reading
is reached.
pH calibration consideration - Standard buffer solution
The meter uses two series of standard buffer solution: USA series and NIST series, and also customer-defined
solution. Please see the table below for the two series of standard buffer solution. For customer-defined solution,
please select it in setup menu parameter P1.1.
Icons
pH standard buffer solution series
USA series
NIST series
Three-point calibration
1,68 pH and 4.00 pH
1,68 pH and 4.01 pH
7.00 pH
6.86 pH
10.01 pH
9.18 pH
Three-point calibration
The instrument can perform 1-3 point calibration. The first point of calibration must be 7.00 pH (or 6.86 pH)
standard solution, then select other standard solution to perform the second and the third point calibration; the
meter is able to recognize the buffer solutions in analysis. During the calibration process, display get blue color
and show the slope of acidity range and alkalinity range respectively.
USA standard
NIST standard
Icons
Suited range
One-point calibration
7.00 pH
6.86 pH
Accuracy
≤ ±0.1pH
Two-point calibration
7.00 pH and
4.00 pH or 1,68 pH
6.86 pH and
4.01 pH or 1,68 pH
Range<7.00pH
7.00 pH and 10.01 pH
6.86 pH and 9.18 pH
Range>7.00pH
Three-point calibration
7.00 pH, 4.00 pH or 1,68
pH, 10.01 pH
6.86 pH, 4.01 pH or
1,68 pH, 9.18 pH
Large Range
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 before the
next calibration.

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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
Due calibration
Pre-set calibration interval (begin from the date of last calibration) to
remind due calibration in a preset period per parameter P1.2 (DC)
During due calibration, Er 7 in red color appears on LCD.
The meter can’t continue operation and Er 7 icon disappears until
the calibration is done, or when select No per parameter P1.2.
Note: If DHS electrode is link, due data calibration is refer to DHS last calibration (is possible to check when
DHS is activated or in P1.3 parameter setting -next paragraph-)
Check calibration date
Check the date and time of last calibration to decide whether new calibration is needed. Please refer to parameter
setting P1.3. If DHS electrode is link last calibration date is refer to DHS last calibration.
pH Meter Calibration
Press key to enter into the calibration mode (the display get blue color), “CAL 1” blinks at the top right of
LCD and “7.00 pH ”blinks at the bottom right of LCD, indicating using pH 7.00 buffer solution to make the 1st
point calibration.
Rinse pH electrode in pure water, allow it to dry, and submerge it in pH 7.00 buffer solution. Stir the solution
gently and leave it 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 stable.
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. After the 1st point calibration, 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.
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, stability icon displays on LCD. Press key to calibrate the meter.
Display shows “End” and slope.
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.

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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 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 appears on LCD. Press key to calibrate the meter.
Display shows “End” icon and slope. Than the meter goes automatically to the measurement mode, displays
stable measuring value and calibration guide icons.
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.
Customer calibration
example of 1.60pH and 6.50pH calibration solution
Select CUS in the setup menu P1.1. The meter enters into Customer-defined calibration mode. 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.
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. For automatic temperature
compensation (ATC), the temperature value does not blink. When press key, the main value blinks.
Press and keys to adjust the main 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.
Note: For manual temperature compensation (MTC), when LCD displays the stable measuring value and
icon, press key, then the temperature value blinks, press and keys to adjust the temperature
value, and press key to confirm it. Then the main value blinks. Follow the above procedures to adjust
the main value and calibrate the meter.
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. For automatic temperature
compensation (ATC), the temperature value does not blink. When press key, the main value blinks.
Press and keys to adjust the main value to 6.50, then press key to calibrate the meter. After
calibration is done, the meter goes to the measurement mode.
Note: For manual temperature compensation (MTC), when LCD displays the stable measuring value and
icon, press key, then the temperature value blinks, press and key to adjust the temperature
value, and press key to confirm it. Then the main value blinks. Follow the above procedures to adjust the
main value and calibrate the meter.

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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.
As for the standard calibration the meter show on the LCD one or more icons indicating the suited range
Measurement
Rinse pH electrode in pure water, allow it to dry, and submerge it in tested solution. Stir the solution briefly and
allow it to stay in the tested solution until icon appears on LCD and a stable reading is reached which is pH
value of tested solution.
Factory default setting
For factory default setting, please refer to parameter P1.5. Per parameter P1.5, 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 -1). When calibration or measurement fails, please restore the
meter to factory default setting and then perform re-calibration or measurement. Please note once set the
factory default, all the data deleted will not be retrievable.
User’s pH buffer
Icons show on the display
6.5 – 7.5
< 6.5
> 7.5
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.
1 st point calibration
Sample
Test
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
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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Self-diagnosis information
Display Icons
Contents
Checking
Wrong pH buffer solution or the
recognition of calibration solution out of
range
1.Check whether pH buffer solution is correct.
2.Check whether the meter connects the
electrode well.
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 whether there are bubbles in glass
bulb.
2.Replace with new pH electrode.
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.
Electrode slope out of range
（<85%or >110%）
pH measuring range out of range （<-2.00
pH or >16.00pH）
1.Check whether the electrode is suspended.
2.Check whether the meter connects the
electrode well.
3.Check whether the electrode is damaged
Enter in pre-set due calibration to remind
due calibration
Press key to perform calibration or cancel
due calibration setup per parameter P1.2
pH electrode maintenance
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 jack. Clean
with medical cotton and alcohol if necessary.
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.
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, the
electrode should be washed with pure water and dried. 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.
Regenerate 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 30 seconds, then wash the electrode in pure water, then submerge it in soaking
solution for 24 hours.

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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: if 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.
mV 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 gently and
leave It solution until icon appears, and get the reading which is ORP value.
ORP means Oxidation Reduction Potential. The unit is mV.
ORP
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.
Clean and activate ORP electrode
After the electrode has been used over 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:
• For inorganic pollutant, submerge the electrode in 0.1mol/L dilute hydrochloric acid for 30 minutes, then
wash it in pure water, then submerge it in the soaking solution for 6 hours.
•For organic or lipid pollutant, clean the platinum surface with detergent, then wash it in pure water, then
submerge it in the soaking solution for 6 hours.
•For heavily polluted platinum surface on which there is oxidation film, polish the platinum surface with
toothpaste, then wash it in pure water, then submerge it in the soaking solution for 6 hours.
Conductivity
Conductivity cell
Two-ring cells with built-in temperature sensor can be used on this instrument. The conductivity cell uses a BNC
connector while the temperature probe uses an RCA connector. When submerge the conductivity electrode in
solution, stir the solution briefly to eliminate the air bubbles and improve response and stability.
Conductivity cell constant
The meter matches conductivity electrodes of three constants: K=0.1, K=1.0 and K=10.0. Please refer to chart
below for measuring range. Set constant per parameter P2.1.

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Range
＜20 μS/cm
0.5 μS/cm~100 mS/cm
＞100mS/cm
Conductivity
electrode constant
K=0.1 cm-1
K=1.0 cm-1
K=10 cm-1
Standard solution
84μS/cm
84 μS/cm
1413 μS/cm
12.88 mS/cm
111.9 mS/cm
Conductivity calibration solutions
The meter uses conductivity standard solution of USA series. The meter can recognize the standard solution
automatically, can perform one-point or multi-point calibration (the maximum is four-point calibration). The
calibration guide icons at the bottom left of LCD correspond to the four standard values.
Calibration guide icons
Calibration solution series
Range
84 μS/cm
0-200 μS/cm
1413 μS/cm
200-2,000 μS/cm
12.88 mS/cm
2-20 mS/cm
111.9 mS/cm
20-200 mS/cm
Calibration intervals
•The meter is calibrated before leaving the factory and can generally be used right out of the box.
•For high accuracy measurements or large temperature deviation from the reference temperature (25°C),
perform calibration per week.
•Use conductivity standard solution to check whether there is error. Perform calibration for large error.
•For new electrode or factory default setting, perform 3-point or 4-point calibration. Choose closer
standard solution to the sample solution to perform 1- point or 2-point calibration. For example: 1413
μS/cm standard solution is suited for range 0-2,000 μS/cm.
1-point and multi-point calibration
For 1-point calibration after 3-point or 4-point calibration, the previous calibration value in the same range will
be replaced, meanwhile, the meter will show the calibration guide icon of this point, other two calibration guide
icons will be deleted, but the chip will reserve the last calibration data. When choose multi-point calibration,
perform calibration from low to high concentration to avoid standard solution of low concentration being
contaminated.
Reference temperature
Reference temperature of factory default is 25°C. Other reference temperature can also be set for range 15°C –
30°C. Select per parameter P2.5.
Temperature coefficient
The temperature compensation coefficient of the meter setting is 1.91%. However, the conductivity temperature
coefficient is different for solutions of a different variety and concentration. Set per parameter P2.6..
Note: When the coefficient for the temperature compensation is set to 0.00 (no compensation), the
measurment value will be based on the current temperature.

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Solution
Temperature compensation coefficient
NaCl solution
2.12%/°C
5% NaOH solution
1.72%/°C
Dilute ammonia solution
1.88%/°C
10% hydrochloric acid solution
1.32%/°C
5% sulfuric acid solution
0.96%/°C
Avoid contamination of standard solution
Conductivity standard solution has no buffer. Please avoid being contaminated during usage. Submerge the
electrode in standard solution before wash the electrode and allow it dry. Please renew conductivity standard
solution frequently especially for standard solution of low concentration 84μS/cm. The contaminated standard
solution can affect accuracy.
Due calibration
Pre-set calibration interval (begin from the date of last calibration) to remind
due calibration in a preset period per parameter P2.3 (DC).
During due calibration, Er 7 in red color appears on LCD.
The meter cannot continue operation and Er 7 icon disappears until
the calibration is done, or when select No per parameter P2.3.
Check the calibration date
Check the last calibration date to see whether a new calibration is needed per parameter P2.4.
Conductivity Calibration
example of calibration at 1413μS/cm
Rinse conductivity electrodes in pure water, allow it to dry, wash with a little of standard solution and submerge
it in standard solution. Stir the solution briefly and allow it to stay in the solution until a stable reading is reached.
Press key to enter into the calibration mode. The meter’s display gets blue color and will show blinking “std”
at the top right, and scanning and locking process of calibration solution at the bottom right.
Er 2 appears if press key before the value is stable.
When the meter locks 1413 μS, stability icon displays on LCD. Press key to calibrate the meter. End icon
appears after calibration is done. The meter returns to the measurement mode
and LCD shows icon at the bottom left.
If return from calibration mode without calibration, press key to return to the measurement mode without
calibration.
For multi-point calibration repeat the procedure.

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Customer calibration
example of calibration at 147μS/cm
Select CUS in the setup menu P2.2; the meter enters into customer-defined calibration mode. When press
LCD shows blinking CUS at the top right, indicating that the meter enters into customer-defined calibration and
the display gets blue color.
Rinse the electrode in pure water, allow it to dry, and submerge it in 147 μS/cm standard solution. Stir the solution
briefly and allow it to stay in the solution until a stable reading is reached and stability icon appears on LCD.
When press key, the measuring value blinks. “CUS” icon appears at the right top of the screen. Press
and key to adjust the measuring value to 147 μS/cm, and press key to calibrate the meter. After the
calibration is done, the screen shows “End” icon and returns to the measurement mode.
Note: When there is no temperature sensor and manual temperature compensation (MTC) is adopted, the
temperature value blinks when press key, press and key to adjust the temperature value,
and when press key, conductivity value blinks.
Only 1-point calibration for customer-defined calibration. The value set in “customer-defined” is at a fixed
temperature. There is no regulations of temperature coefficient and reference temperature. The meter has to
perform calibration and measurement at the same temperature to avoid large error. The meter cannot recognize
customer-defined calibration solution.
As for the standard calibration also in customer calibration the meter show on the LCD one icon indicating the
suited range.
Submerge the cell in a conductivity
standard solution:
•84 μS L
•1413 μS M
•12.88mS H
•111.9mS H
Press key when icon appears,
to confirm the calibration, the meter enters
into measurement mode automatically.
Sampe
Test
Press to turn
on the meter
Press key to
enter into the
calibration mode
Multipoint
calibration
Single point
calibration

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Measure
Rinse conductivity electrode in pure water, allow it to dry, and submerge it in the sample solution. Stir the solution
briefly and allow it to stay in the sample solution until a stable reading is reached and stability
icon appears on LCD, then get the reading value which is the conductivity value of the solution.
During the process of calibration and measurement, the meter has self-diagnosis functions
Display Icons
Contents
Checking
Wrong conductivity calibration solution or
the meter recognition of calibration
solution out of range
1.Check whether conductivity calibration
solution is correct.
2.Check whether the meter connects the
electrode well.
3.Check whether the electrode is damaged.
Press key when measuring value
is not stable during calibration.
Press key when icon appears
During calibration, the measuring value is
not stable for ≥3min.
1.Shake the electrode to eliminate bubbles in
electrode head.
2.Replace with new pH electrode.
Enter in pre-set due calibration to remind
due calibration
Press key to perform calibration or cancel
due calibration setup per parameter P2.3.
Factory default setting
For factory default setting, please refer to parameter P2.8. All calibration data is deleted and the meter restores
to the theory value. Some functions restore to the original value (refer to appendix -1). When calibration or
measurement fails, please restore the meter to factory default setting and then perform re-calibration or
measurement. Please note once set the factory default, all the data deleted will not be retrievable.
Conductivity electrode maintenance
Always keep the conductivity electrode clean. Before taking a measurement, rinse the electrode in pure water
and then rinse it in the sample solution. When submerge the electrode in solution, stir the solution briefly to
eliminate air bubbles and allow it to stay until a stable reading is reached. For conductivity electrode which keeps
dry, soak the electrode in pure water for 5-10 minutes. Rinse the electrode in pure water after measurement.
If the electrode coated with platinum black is invalid, immerse it in 10% nitric acid solution or 10% hydrochloric
acid solution for 2 minutes, then rinse the electrode in pure water. If the electrode still does not work, re-coat
platinum black, or replace with a new conductivity electrode.
Relations between TDS, Salinity and conductivity
TDS and conductivity is linear related, the conversion factor is 0.40-1.00. Adjust per parameter P3.1. The factory
default setting is 0.71. The meter can only be calibrated in Conductivity mode and not TDS mode. After calibration
of conductivity, the meter can switch from conductivity to TDS or salinity.
Adjust TDS conversion factor per parameter P3.1 according to the data collected during testing

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Common used TDS conversion factors
Conductivity of solution
TDS conversion factor
0-100 μS/cm
0.60
100-1,000 μS/cm
0.71
1-10 mS/cm
0.81
10-100 mS/cm
0.94
Datalogger functions (pH70+DHS, COND70+, PC70+DHS)
Manual storage
When icon appears, press momentarily key, M+ icon and
storage serial number appear on LCD, storing measuring information.
Automatic timing storage
Set the storage timing into the setup menu P6.3, icon appears on LCD
and the meter enters into the timing storage mode. Press momentarily
key to start the data automatic storage, flashes
on the display. To stop the recording, press momentarily key,
icon stops flashing and the meter stops automatic storage.
In automatic storage mode, manual storage does not work.
Set time 00:00 per parameter P6.3 to exit from the automatic storage mode.
Recall stored value
In the measurement mode, press key to recall the last stored
measuring value. RM icon and storage serial number appear on the display.
Press and keys to slide all the stored values.
Press to return in measurement mode.
Clear stored value
Select YES into the setup menu P6.7 to clear all stored value.

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Setup Menu
Main menu
In the measurement mode, press key to enter in P1.0, then press and to slide the main menu:
P1.0→P2.0→P3.0→P6.0.
P1.0: pH parameter setting menu,
P2.0: Conductivity parameter setting menu,
P3.0: TDS parameter setting,
P6.0: Basic parameter setting menu.
Submenu
In P1.0 mode, press key to enter in submenu P1.1 of pH parameter setting,
then press and keys to switch among submenu: P1.1→P1.2→P1.3→P1.4→P1.5→P1.6→P1.7.
In P2.0 mode, press key to enter in submenu P2.1 of conductivity parameter setting, then press
and keys to switch among submenu: P2.1→P2.2→P2.3→P2.4→P2.5→P2.6→P2.8→P2.9.
In P3.0 mode, press key to enter in submenu P3.1 to adjust TDS factor.
In P6.0 mode, press key to enter in submenu P6.1 of basic parameter setting, then press
and keys to switch among submenu: P6.1→P6.2→P6.3→P6.4→P6.5→P6.6→P6.7→P6.8.