Apera Instruments PC 8500 User manual

PC8500 Portable pH/Conductivity Meter
Manual
PH 8500 Portable pH Meter
EC 8500 Portable Cond. Meter
PC 8500 Portable pH/Cond. Meter
APERA INSTRUMENTS (Europe) GmbH
www.aperainst.de

Table of Contents
1. Introduction ---------------------------------------------------------------------------------------------------------------------------
2. Specifications ------------------------------------------------------------------------------------------------------------------------
3. Instrument Description -------------------------------------------------------------------------------------------------------------
3.1. LCD display----------------------------------------------------------------------------------------------------------------------
3.2. Keypad functions ---------------------------------------------------------------------------------------------------------------
3.3. Meter socket ----------------------------------------------------------------------------------------------------------------------
3.4. Display mode----------------------------------------------------------------------------------------------------------------
3.5. Store, recall and clear readings---------------------------------------------------------------------------------------------
3.6. Auto. power off-------------------------------------------------------------------------------------------------------------
3.7. Temperature adjustment --------------------------------------------------------------------------------------------------
4. pH measurement --------------------------------------------------------------------------------------------------------------------
4.1. pH electrode information------------------------------------------------------------------------------------------------------
4.2. pH calibration consideration -------------------------------------------------------------------------------------------------
4.3. pH calibration --------------------------------------------------------------------------------------------------------------------
4.4. Customer-defined calibration -------------------------------------------------------------------------------------------------
4.5. Sample test -----------------------------------------------------------------------------------------------------------------------
4.6. pH electrode maintenance----------------------------------------------------------------------------------------------------
5. mV measurement---------------------------------------------------------------------------------------------------------------------
6. Conductivity measurement ----------------------------------------------------------------------------------------------------------
6.1. Conductivity electrode information-------------------------------------------------------------------------------------------
6.2. Conductivity calibration consideration-------------------------------------------------------------------------------------
6.3. Conductivity calibration--------------------------------------------------------------------------------------------------------
6.4. Relations between TDS, salinity, and conductivity------------------------------------------------------------------
6.5. Customer-defined calibration--------------------------------------------------------------------------------------------------
6.6. Sample test------------------------------------------------------------------------------------------------------------------------
6.7 Conductivity electrode maintenance-----------------------------------------------------------------------------------------
7. Parameter setting----------------------------------------------------------------------------------------------------------------------
7.1. Main menu-------------------------------------------------------------------------------------------------------------------------
7.2. Sub-menu --------------------------------------------------------------------------------------------------------------------------
7.3. Sub-menu of pH parameter setting -------------------------------------------------------------------------------------
7.4. Sub-menu of conductivity parameter setting ------------------------------------------------------------------------
7.5. Sub-menu of basic parameter setting ---------------------------------------------------------------------------------------
8. USB communication-------------------------------------------------------------------------------------------------------------------
9. Meter Kits---------------------------------------------------------------------------------------------------------------------------------
10. Warranty--------------------------------------------------------------------------------------------------------------------------------
Appendix I: Parameter setting and factory restoring setting-------------------------------------------------------------------
Appendix II: Abbreviation Glossary---------------------------------------------------------------------------------------------------
Appendix III: Self-diagnosis information---------------------------------------------------------------------------------------------
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Diagram-1
1. Introduction
Thanks for purchasing 8500 series portable pH/Conductivity meter.
This meter is a perfect combination of the most advanced electronics technology, sensor technology, and
software design, and is the most cost-effective portable pH/Conductivity measuring meter.
In order to use and maintain the instrument properly, please read the manual thoroughly before use.
In order to improve instrument performance continuously, we reserve the right to change the manual and
accessories without giving notice in advance.
1.1. Measurement parameters
Measurement parameters
PH8500
EC8500
PC8500
pH/mV
√
√
Conductivity/TDS/Salinity
√
√
Temperature
√
√
√
1.2. Basic features
The microprocessor-based portable meter features automatic calibration, automatic
temperature compensation, function set-up, self-diagnostics, due calibration reminding,
calibration date checking, automatic power-off and low voltage display. PC8500 meter is
able to measure multiple parameters simultaneously. Please see Diagram -1：attach
pH electrode and conductivity electrode together into the clip to measure simultaneously.
Meet GLP, clock display, manual storage and automatic timing storage, USB port.
The meter’s digital filter improves measurement speed and accuracy. There is
reading stability display.
The package includes portable case, meter, electrode, standard solutions, soaking
solutions, and all accessories, convenient to use in field.
The meter is dust proof and waterproof, meeting the IP57 rating.
1.3. pH measurement features (suited for model PH8500 and PC8500)
1-3 points automatic calibration, the meter provides calibration guide and automatic checking function.
The meter is able to recognize pH standard buffer solutions automatically. There are three options of
standard buffer solution: USA series, NIST series and customer-defined solution.
The meter provides three kinds of reading stability criteria.
1.4. Conductivity measurement features (suited for model EC8500 and PC8500)
1-4 points automatic calibration, the meter provides calibration guide and automatic checking function.
The meter is able to switch among conductivity, TDS and salinity measurement mode.
The meter is able to recognize conductivity standard solutions automatically. There is “Standard”series
and customer-defined solution.

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2. Specifications
2.1. Main specifications
Specifications
Models
pH
Measuring Range
(-2.00 ~ 16.00) pH
PH8500
PC8500
Resolution
0.1/0.01 pH
Accuracy
±0.01pH ±1 digit
Temperature
compensation
(0 ~ 100) °C (manual or automatic)
mV
Measuring Range
±1,999mV
Resolution
±200 mV:0.1mV;others:1 mV
Accuracy
±0.1% F.S ±1 digit
Conductivity
Measuring Range
Conductivity：0~200 mS/cm，
divided into five ranges:
(0.00~19.99) μS/cm; (20.0~199.9) μS/cm;
(200~1999) μS/cm; (2.00~19.99) mS/cm;
(20.0~199.9) mS/cm
TDS: (0~100) g/L, Salinity: (0~100) ppt
EC8500
PC8500
Resolution
0.01/0.1/1μS/cm 0.01/0.1mS/cm
Accuracy
±1.0% F.S ±1 digit
Temperature
compensation
(0 ~ 100) °C (manual or automatic)
Electrode constant
0.1 / 1 / 10cm-1
Temperature
Measuring Range
-10~110°C
PH8500
EC8500
PC8500
Resolution
0.1℃
Accuracy
±0.5℃±1 digit
2.2. Other specifications:
Data storage
500 groups
Storage content
Serial number, date, time, measuring value,
measuring unit and temperature value
Output
USB
Power
AA batteries × 3 (1.5V× 3)
IP rating
IP57 waterproof and dust proof
Dimension & Weight
Meter: (86×196×33 ) mm / 335 g
Portable case: (330×270×82 ) mm /1.3 kg
PH8500
EC8500
Portable case: (370×270×77 ) mm /1.8 kg
PC8500

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3. Instrument Description
3.1. LCD Display：
(1) —Measuring mode icons
(2) —Measurement reading
(3) —Timing storage icon. When this icon appears, the meter is in the automatic storage mode
(4) —Date and time, or prompts of special display mode
(5) —Units of date and time
(6) —Units of measurement
(7) —Temperature units
(8) —Units of calibration value
(9) —Standard calibration value, the serial number for storage and recall, and prompts of special
display mode
(10) —Storage and recall icons,
M+ —Measurement to be stored icon, RM —Reading to be recalled icon
(11) —Temperature value, and prompts of special display mode
(12) —Temperature compensation icons ,ATC —automatic temperature compensation,
MTC —manual temperature compensation
(13) —Calibration guide icon
(14) —USB icon，when this icon appears, the meter connects the computer
(15) —Stability icon of readings
(16) —Low battery icon, when this icon appears, please renew the battery
(17) —Auto. Hold icon of readings
Diagram-2
LCD
⑰
HOLD

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3.2. Keypad Functions
3.2.1. Keypad operations
Short press <1.5 seconds , Long press >1.5 seconds.
Turn on the meter: press to turn on the meter.
Turn off the meter: In the measurement mode, press and hold for 2 seconds to turn off the meter.
Notes: In the calibration mode or the parameter set-up mode, pressing is invalid. Please press
key to return to the measurement mode, then press to turn off the meter.
Chart –1 Keypad operations and descriptions
Keypad
Operations
Descriptions
Short 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.
Short press
Select measurement parameter:
PH8500 pH meter: →;
EC8500 Conductivity meter: →→;
PC8500 pH/Conductivity meter: →→→→ →;
Short press
In the measurement mode, press this key to enter in the calibration
mode;
In the auto. hold mode(HOLD), recall mode (RM) or other mode, press
this key to return to the measurement mode,
Short press
In the measurement mode, press this key to enter in the parameter setup
main menu;
In the calibration mode, press this key to make calibration;
In the parameter set-up mode, press this key to select programs;
In the recall mode(RM),press this key to return to the measurement
Mode.
Diagram-3
Keypad

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Short/
long press
In the measurement mode, long press to enter manual temperature
compensation mode, long press this key or short press to increase
temperature value;
In the measurement mode, press this key to store the measuring value;
In the recall mode (RM), short press this key to change the storage serial
number, press and hold this key to change the number quickly;
In the parameter set-up mode, press this key to change the serial
number of the main menu and the sub-menu;
In the sub-menu mode, press this key to change parameters and setup.
Short/
long press
In the measurement mode, long press to enter manual temperature
compensation mode, long press this key or short press to decrease
temperature value;
In the measurement mode, press this key to recall the last stored value;
In the recall mode (RM), press momentarily this key to change the
storage serial number, press and hold this key to change the number
quickly;
In the parameter set-up mode, press this key to change the serial
number of the main menu and the sub-menu;
In the sub-menu mode, press this key to change parameters and setup.
3.3. Meter Socket
Electrode socket displays as Chart –2. USB socket displays as Chart–3.
Chart –2 Sockets for meters
Models
Photos
Description
PH 8500
pH meter
BNC socket (right) —connect pH
electrode or ORP electrode,
RCA socket (middle) —connect
temperature probe
EC 8500
Conductivity meter
Eight-pin socket (left) —connect
conductivity electrode
PC 8500
pH/Conductivity meter
BNC socket (right) —connect pH
electrode or ORP electrode,
RCA socket (middle) —connect
temperature probe
Eight-pin socket (left) —connect
conductivity electrode

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Chart –3 USB socket
Functions
Connect to meter
Description
USB communication
The meter has USB communication
function, connecting the meter to a
computer by USB cable.
Computer or external
power supply
Computer power supply: connect the
meter to a computer by USB cable,
External power supply: use USB cable
and USB adapter, input voltage:
AC110V~220V.
3.4. Display Mode
3.4.1 Reading stability display mode
When the measuring value is stable, smiley icon appears on LCD,
see Diagram –4. If the icon does not appear or flash, please do not
record the reading value or make calibration until the measuring value is
stable. Per parameter P1.3, there are 3 criteria for stability standard:
(Normal), (High) and (Low). The factory default is set “Normal”.
"High”is set for stability over a longer time, “Low”is set for stability over a
shorter time. User can select suitable stability criteria according to different
testing requirement.
3.4.2. Automatic lock-up display mode
Select On from parameter P3.6 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 –5.
In the HOLD mode, press to release lock-up.
3.5. Store, Recall and Clear Readings
3.5.1. Manual storage
When the measurement is stable, short press key,
M+ icon and storage serial number appear on LCD, storing measuring
information, see Diagram –6.
3.5.2. Automatic timing storage
Set the storage timing (eg. 3 minutes) in parameter setting P3.3, icon
appears on LCD and the meter enters into the timing storage mode. When
short press key, key flashes and the first measuring value is stored.
After 3 minutes, the 2nd measuring value is stored. See Diagram –7: the meter
stores automatically eight measuring values. When short press key,
icon stops flashing and the meter stops automatic storage. In automatic
storage mode, manual storage does not work. Set time 0 in parameter setting
P3.3 to exit from the automatic storage mode.
Diagram - 4
Diagram - 6
Diagram - 7
Diagram - 5

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3.5.3. Recall stored value
In the measurement mode, press key to recall the last stored
measuring value. See Diagram –8: 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 the
stored measuring value quickly. Press to return to measuring mode.
3.5.4. Clear stored value
Select YES per parameter P3.6 to clear all stored value, refer to clause 7.5.
3.6. Auto. Power-off
The meter will be power-off after the meter stops operation for 20 minutes. To set automatic power off time in
parameter setting P3.7
3.7. Temperature Adjustment
When the temperature probe is not connected to the meter, press and hold key or key,
temperature value flashes, then press (or press and hold) key or key to change the temperature
value, and press key to confirm.
4. pH measurement
4.1. pH electrode information
The meter connects to 201T-F plastic three-in-one combination pH electrode with built-in temperature sensor,
with automatic temperature compensation function. Electrode housing is made of polycarbonate engineering
plastics, which is corrosion and impact resistant. The BNC socket of electrode connects pH socket. RCA
socket connects temperature socket. When dipping pH electrode in the solution, please stir the solution
briefly to eliminate any air bubbles and allow it to stay in the solution until the reading is stable
4.2. pH Calibration Consideration
4.2.1. Standard buffer solution
The meter uses two series of standard buffer solution: USA series and NIST series, each series consists of 5
groups solution, icons see Chart - 4
Chart - 4 pH standard buffer solution series
Calibration guide icons
pH standard buffer solution series
USA series (USA)
NIST series (NIS)
Three-point
calibration
1.68 pH and 4.00 pH
1.68 pH and 4.01 pH
7.00 pH
6.86pH
10.01 pH and 12.45 pH
9.18 pH and 12.45 pH
4.2.2. Three-point calibration
The instrument can perform 1-3 points calibration. The first point 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,
see Chart-5.
Diagram - 8

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Diagram - 10
Chart - 5 Three-point calibration mode
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→4.00 or 1.68pH
6.86 pH→4.01 or 1.68pH
Range<7.00pH
7.00 pH→10.01 or 2.45pH
6.86 pH→9.18 or 12.45pH
Range>7.00pH
Three-point
calibration
7.00pH→4.00 or1.68pH
→10.01 or12.45pH
6.86pH→4.01or 1.68pH
→9.18 or 12.45pH
Large Range
4.2.3. Calibration intervals
Calibration intervals depend on the sample, the electrode performance, and the required accuracy. For high
accuracy measurements (≤ ±0.03pH), 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. The meter must be re-calibrated in the following situations:
(a) New probe, or probe that is unused for a long period of time
(b)After measuring acids (pH<2) or alkaline solutions (pH>12)
(c)After measuring a solution that contains fluoride or a concentrated organic
solution
(d) If the solution’s temperature differs greatly from the calibration solution
temperature
4.2.4. Due calibration
Preset calibration interval (begin from the date of last calibration) to remind due
calibration in a preset period in parameter setting P1.4 (clause 7.3). During due
calibration, Er5icon appears on LCD (see Diagram –9). The meter can not
continue operation and Er5icon disappears until the calibration is done, or
when select “No”in parameter setting P1.4.
4.2.5. Check calibration date
Check the date and time of last calibration to decide whether new calibration is
needed. Please refer to parameter setting P1.5 (clause 7.3).
4.3. pH Calibration (take three-point calibration as an example)
4.3.1. The 1st point calibration
（a）Press key to enter into the calibration mode, 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.
（b）Rinse pH electrode in pure water, allow it to dry, and submerge it in
pH7.00 buffer solution. Stir the solution briefly and allow it to stay in the buffer
solution until a stable reading is reached. LCD displays , press to
finish 1st point calibration, meter goes to measurement mode, the bottom left of
LCD indicating , See Diagram –10.
Diagram - 9

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4.3.2. The 2nd point calibration
Press key to enter into the calibration mode, CAL2 blinks at the top right of LCD, indicating make the 2nd
point calibration. Rinse pH electrode in pure water, allow it to dry, submerge it in pH4.00 buffer solution, Stir
the solution briefly and allow it to stay in the buffer solution until a stable reading is reached. The
meter’s display will show scanning and locking process of calibration buffer solution at the bottom right of
LCD. When the meter locks 4.00 pH, stable icon displays on LCD. Press key to calibrate the meter.
electrode slope of acidity range display after calibration is done, the 2nd point calibration finished, meter goes
to measurement mode, the bottom left of LCD indicating .
4.3.3. The 3rd point calibration
Press key to enter into the calibration mode, CAL 3 blinks at the top right of LCD indicating make the 3rd
point calibration. rinse pH electrode in pure water, allow it to dry, submerge it in pH10.01 buffer solution, Stir
the solution briefly and allow it to stay in the buffer solution until the reading is stabilized. The meter’s display
will show scanning and locking process of calibration buffer solution at the bottom right of LCD. When the
meter locks 10.01pH, stable icon displays on LCD. Press key to calibrate the meter. Electrode
slope of acidity range display after calibration is done. After the 3rd point calibration is completed, meter goes
to measurement mode, the bottom left of LCD indicating .
Notes:
(a) The meter can perform 1-3 points calibration. When the 1st point calibration is done, meter goes to
measurement mode under 1st point calibration mode. Same procedure as 2nd point calibration and 3rd
point calibration.
(b) During calibration process, if a stable reading has not been reached, no displays on
LCD, press key, Er2 will displays on LCD, See Chart–6
(c) In calibration mode, press key to exit.
4.4. Customer-defined calibration (take 1.60 pH and 6.50 pH calibration solution as an example)
4.4.1. Select CUS from parameter setting P1.1 (please refer to clause 7.3 for customer-defined solution). The
meter enters into Customer-defined calibration mode.
4.4.2. Rinse pH electrode in pure water, allow it to dry, and submerge it in pH1.60 buffer solution. Stir the
solution briefly and allow it to stay in the buffer solution until a stable reading is reached. When LCD displays
the stable measuring value and icon, press key and the measuring value flashes.
CAL1 blinks at the top right of LCD, indicating 1st point calibration of customer-defined solution. Press
key or key to adjust the measuring value to 1.60, then press key to calibrate the meter. After
calibration is done, meter goes to measurement mode.
4.4.3. Rinse pH electrode in pure water, allow it to dry, and submerge it in pH 6.50 buffer solution. Stir the
solution briefly and allow it to stay in the buffer solution until a stable reading is reached. When LCD displays
the stable measuring value and icon, press key and the measuring value flashes. CAL 2 blinks at
the top right of LCD, indicating 2nd point calibration of customer-defined solution, 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.

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Press key to enter
into the calibration
mode.
Notes:
（a）For manual temperature compensation (temperature probe didn`t plug in RCA socket), when
press key, the temperature value flashes. Press key or key to adjust the temperature
value, and then press key, pH measuring value flashes.
(b) The meter can perform 1-2 points customer-defined calibration. When the 1st point calibration is
done, the meter goes to measurement mode automatically. Likewise in customer-defined 2nd point
calibration.
(c) The value set in “Customer-defined”is at a fixed temperature. The meter is suggested to perform
calibration and measurement at the same temperature to avoid large error. The meter cannot
recognize customer-defined calibration solution.
4.5. Sample Test
4.5.1. Rinse pH electrode in pure water, allow it to dry, and submerge it in sample solution. Stir the solution
briefly and allow it to stay in the sample solution until the stable value and icon appears on LCD, get the
reading which is pH value of sample solution, please refer to Diagram-11 for calibration and measurement
process of pH meter.
Diagram –11 Calibration and measurement process of pH meter
4.5.2. 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.
Submerge the electrode
in pH4.00 solution, press
key when icon
appears.
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.
1st point calibration is
done, meter goes into
measurement mode.
1st point calibration
Sample
Test
2nd point
calibration
3rd point calibration
2nd point calibration is
done, meter goes into
measurement mode.
3rd point calibration is
done, meter goes into
measurement mode
Submerge the electrode
in pH10.01solution,press
key when icon
appears.
Press key to enter
into the calibration
mode.

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Chart –6 Self-diagnosis information of pH measurement mode
Display
Icons
Contents
Checking
Wrong pH buffer solution or the buffer
solution out of range.
1.Check whether pH buffer solution is correct.
2.Check whether the meter connects the electrode
properly.
3.Check whether the electrode is damaged.
Press key when measuring value
isnot 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 a new pH electrode.
pH electrode performance error
( zero potential <-60mV or >60mV,
slope <75%）
1.Check whether there are bubbles in glass bulb.
2.Check whether pH buffer solution is correct.
3.Replace with new pH electrode.
Enter in pre-set due calibration date
reminder
Press key to perform calibration or cancel due
calibrationsetup per parameter P1.4
4.5.3. pH temperature principle
Please note that the closer the temperature of the sample solution is to the calibration solution, the more
accurate will be the readings.
4.5.4. Factory default setting
For factory default setting, please refer to parameter P1.6 (clause 7.3). 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 irretrievable.
4.6. pH Electrode Maintenance
4.6.1. Daily maintenance
The soaking solution contained in the supplied protective bottle is used to maintain activation in the glass
bulb and junction. Loosen the capsule, remove the electrode and rinse in pure water before taking a
measurement. Insert the electrode and tighten the capsule after measurements to prevent the solution from
leaking. If the soak solution is turbid or moldy, replace the solution. (The method to prepare this solution: add
26g KCL in 100ml pure water).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 socket. Clean with
medical cotton and alcohol if necessary.
4.6.2. Calibration buffer solution
For calibration accuracy, the pH of the standard buffer solution must be reliable. The buffer solution should be
refreshed often, especially after heavy use.
4.6.3. Protect glass bulb

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The sensitive glass bulb at the front of the combination electrode should not come in contact with hard
surfaces. Scratches or cracks on the electrode will cause inaccurate readings. Before and after each
measurement, wash the electrode with pure water and then throw off the excess water on the electrode. Do
not clean the glass bulb with a tissue for it will affect the stability of the electrode potential and increase the
response time. The electrode should be thoroughly cleaned if a sample sticks to the electrode. Use a solvent
if the solution does not appear clean after washing.
4.6.4. Renew glass bulb
Electrodes that have been used over a long period of time, will become aged. Submerge the electrode in 0.1
mol/L hydrochloric acid for 24 hours, then wash the electrode in pure water, then submerge it in soaking
solution for 24 hours. The method to prepare 0.1mol/L hydrochloric acid: dilute 9mL hydrochloric acid in pure
water to 1000mL. For serious passivation, submerge the bulb in 4% HF (hydrofluoric acid) for 3-5 seconds,
and wash it in pure water, then submerge it in the soaking solution for 24 hours to renew it.)
4.6.5. Clean contaminated glass bulb and junction (see Chart –7)
Chart –7 Clean contaminated glass bulb and junction
Contamination
Cleaning Solutions
Inorganic metal oxide
Dilute acid less than 1mol/L
Organic lipid
Dilute detergent (weak alkaline)
Resin macromolecule
Dilute alcohol, acetone, ether
Proteinic haematocyte sediment
Acidic enzymatic solution (saccharated yeast tablets)
Paints
Dilute bleacher, peroxide
Notes:
The electrode housing is polycarbonate. When using cleaning solutions, take precautions with
carbon tetrachloride, trichlorethylene, tetrahydrofuran, acetone, etc, as these will dissolve the
housing and invalidate the electrode.
5. mV Measurement:
5.1. Press key, and switch the meter to mV measurement mode. Connect ORP electrode (purchased
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:
5.2.1. ORP measurement does not require calibration. When the user is not sure about ORP electrode
quality or measuring value, use ORP standard solution to test mV value and see whether ORP electrode or
meter works properly.
5.2.2. Clean and activate ORP electrode
After the electrode has been used over long period of time, the platinum surface will get contaminated and
will lead to inaccurate measurements and slow responses. Please refer to the following methods to clean and
activate ORP electrode:

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(a) For inorganic pollutants, 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.
(b) For organic or lipid pollutants, clean the platinum surface with detergent, then wash it in pure water, then
submerge it in the soaking solution for 6 hours.
(c) For heavily polluted platinum surface on which there is an oxidation film, polish the platinum surface with
toothpaste, then wash it in pure water, then submerge it in the soaking solution for 6 hours.
6. Conductivity Measurement:
6.1. Conductivity electrode information
6.1.1. Conductivity electrode
Model 2301T-S plastic conductivity electrode with constant K=1.0 and built-in temperature sensor, with
automatic temperature compensation function. The electrode housing is POM plastic which is corrosion
resistant and impact resistant. When submerging the conductivity electrode in solution, stir the solution briefly
to remove any the air bubbles. This will improve response time and stability.
6.1.2. Conductivity electrode constant
The meter matches conductivity electrodes of three constants: K=0.1, K=1.0 and K=10.0. Please refer to
chart-8 for measuring range. Set constant per parameter P2.1 and refer to clause 7.4.
Chart –8 Electrode constant and measuring range
Range
＜20 μS/cm
0.5μS/cm~100mS/cm
＞100mS/cm
Conductivity
electrode
constant
K=0.1 cm-1
K=1.0 cm-1
K=10 cm-1
Standard
solution
84μS/cm
84μS/cm
1413μS/cm
12.88mS/cm
111.9mS/cm
6.2. Conductivity calibration consideration
6.2.1. Conductivity calibration solutions
The meter uses conductivity standard solution: 84μS/cm, 1413μS/cm, 12.88mS/cm, 111.9mS/cm. Select the
standard solution per parameter P2.2 (clause 7.4). The meter can recognize the standard solution
automatically, can perform one-point or multi-points calibration (the maximum is four-point calibration). The
calibration guide icons correspond to the four standard values. ( corresponds to two groups of solutions)
See chart –9:
Chart –9 Conductivity standard solution series
Calibration guide icons
Calibration solution series
Range
84μS/cm
0-200μS/cm
1413μS/cm
200-2,000μS/cm
12.88mS/cm
2-20mS/cm
111.9mS/cm
20-200mS/cm

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6.2.2. Calibration intervals
(a) The meter is calibrated before leaving the factory and can be used right out of the box.
(b) Perform calibration once per month.
(c) For high accuracy measurements or large temperature deviations from the reference temperature
(25°C), perform calibration per week.
(d) Use conductivity standard solution to check whether there is error. Perform calibration for large errors.
(e) For new electrode or factory default setting, perform 3-point or 4-point calibrations. Choose closer
standard solution to the sample solution to perform 1- point or 2-point calibration.
6.2.3. Reference temperature
Reference temperature of factory default is 25°C. Other reference temperature can also be set for range
15°C –30°C. Select in parameter setting P2.3 and see clause 7.4.
6.2.4. Temperature coefficient
The temperature compensation coefficient of the meter setting is 2.00%/°C. However, the conductivity
temperature coefficient is different for solutions of a different variety and concentration. Please refer to chart
–10 and the data collected during testing. Set per parameter P2.4. and see clause 7.4.
Notes:
When the coefficient for the temperature compensation is set to 0.00 (no compensation), the
measurement value will be based on the current temperature.
Chart –10 Temperature compensation coefficient of special solutions
Solution
Temperature compensation coefficient
NaCl salt 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
6.2.5. Avoid contamination of standard solution
Conductivity standard solution has no buffer. Please avoid any possible contamination during usage.
Submerge the electrode in standard solution before washing the electrode and allow it dry. Please renew
conductivity standard solution frequently especially for standard solution of low concentration 84 μS/cm. The
contaminated standard solution can affect accuracy.

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6.2.6. Due calibration
Pre-set calibration intervals (begin from the date of last calibration) to remind
due calibration in a preset period in parameter setting P2.6 (clause 7.4). During
due calibration, Er5 icon appears on LCD (see Diagram –12). The meter
cannot continue operation and Er5 icon disappears until the calibration is done,
or when select “No”in parameter setting P2.6.
6.2.7. Check the calibration date
Check the last calibration date to see whether a new calibration is needed per parameter P2.7. (clause 7.4.)
6.3. Conductivity Calibration (take calibration with 1413μS/cm as an example)
6.3.1. Rinse pH electrode 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.
6.3.2. Press key to enter into the calibration mode.
The meter’s display will show blinking CAL at the top right, and
scanning and locking process of calibration solution at the bottom right.
When the meter locks 1413 μS, stable icon displays on LCD.
Press key to finish calibration, meter goes into measurement mode.
LCD shows icon at the bottom left. See Diagram –13
6.3.3. For multi-point calibration, please repeat clause 6.3.1-6.3.3 until
all the calibrations are done. The meter can repeat calibration in the
same calibration solution to ensure better accuracy and repeatability
of the reading.
6.3.4. Notes
(a) Er 2 appears if press key before the value is locked.
See chart –12.
(b) If return from calibration mode, press to exit.
6.4. Relations among TDS, salinity and conductivity
6.4.1. TDS and conductivity is linear related. The conversion factor is 0.40-1.00.
Adjust per parameter P2.5. The factory default setting is 0.71 to see clause 7.4.
Salinity and conductivity are interrelated, the factor is 0.5, 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.
6.4.2. Adjust TDS conversion factor per parameter P2.5 according to the data collected during testing. See
chart –11: commonly used TDS conversion factors.
Diagram - 12
Diagram - 13

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Chart –11 Commonly 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
6.5. Customer-Defined Calibration (take 10.50μS/cm standard solution as an example)
6.5.1 Select CUS per parameter P2.2 (please refer to clause 7.4 for customer-defined solution). The meter
enters into Customer-defined calibration mode.
6.5.2.Rinse the electrode in pure water, allow it to dry, and submerge it in 10.50μS/cm standard solution. Stir
the solution briefly and allow it to stay in the solution until a stable reading is reached and icon appears
on LCD. Press key or key to adjust the measuring value to 10.50μS/cm, Press key to calibrate
the meter. meter returns to the measurement mode. In conductivity measurement mode with
customer-defined calibration, the meter does not display electrode calibration guide icon.
Notes:
Note: If use the conductivity electrode without temperature sensor ( manual temperature
compensation (MTC)), when press key, the temperature value flashes. Press key or key
to adjust the temperature value, and press key, then the conductivity value flashes.
6.5.3. Only one-point calibration for customer-defined calibration. The value set in “Customer-defined”is at a
fixed temperature. There is no regulation 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.
6.6. Sample test
6.6.1. 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
icon appears on LCD, then get the reading value which is the conductivity value of the solution.
6.6.2. Press key to switch to TDS and salinity.
6.6.3. During the process of calibration and measurement, the meter has self-diagnosis functions,
indicating the relative information as below: chart –12.

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Chart –12 Self-diagnosis information of conductivity measurement mode
Display
Icons
Contents
Checking
Wrong conductivity calibration solution
or the recognition range of calibration
solution exceeds standard.
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 a new conductivity electrode.
Enter in pre-set due calibration to remind
calibration
Press key to perform calibration or cancel
due calibration setup per parameter P2.6.
6.6.4. Factory default setting
For factory default setting, please refer to parameter P2.8 (clause 7.4). 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 factory default setting is set, all the data deleted will not
irretrievable.
6.7. Conductivity electrode maintenance
6.7.1. 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 submerging 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.
6.7.2. The interaction pole of Model 2301T-S conductivity electrode is coated with platinum black to minimize
electrode polarization and expand measuring range. The platinum black coating applied by a special
processing technology, which improves the electrode performance and the robustness of the coating, If the
platinum black electrode is stained, gently clean the electrode with a soft brush in warm water containing
detergent or alcohol.
7. Parameter setting
7.1 Main menu
In the measurement mode, press key to enter in P1.0, then press or to switch to main menu:
P1.0→P2.0→P3.0. Please refer to Diagram –14.
P1.0: pH parameter setting menu,
P2.0: Conductivity parameter setting menu,
P3.0: Basic parameter setting menu.

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7.2 Sub-menu
7.2.1. In P1.0 mode, press key to enter in sub-menu P1.1 of pH parameter setting, then press
and key to switch among sub-menu: P1.1→P1.2→P1.3→P1.4→P1.5→P1.6, See Diagram–14.
7.2.2. In P2.0 mode, press key to enter in sub-menu P2.1 of conductivity parameter setting, then press
and key to switch among sub-menu: P2.1→P2.2→P2.3→P2.4→P2.5→P2.6→P2.7→P2.8, See
Diagram –14.
7.2.3. In P3.0 mode, press key to enter in sub-menu P3.1 of TDS parameter setting, then press
and key to switch among sub-menu: P3.1→P3.2→P3.3→P3.4→P3.5→P3.6→P3.7→P3.8, See
Diagram –14
Diagram –14 Main menu and sub-menu of parameter setting
P1.1 Select pH standard solution
P1.2 Select resolution
P1.3 Set stability criteria
P1.4 Set due calibration
P1.5 Check calibration date
P1.6 Restore to factory default setting
P2.1 Select electrode constant
P2.2 Select conductivity standard solution
P2.3 Select standard temp.
P2.4 Adjust temperature compensation factor
P2.5 Adjust TDS coefficient
P2.6 Set due calibration
P2.7 Check calibration date
P2.8 Restore to factory default setting
P3.1 Select temperature unit
P3.2 Select backlight time
P3.3 Adjust timing storage time
P3.4 Adjust date
P3.5 Adjust time
P3.6 Clear stored value
P3.7Automatic power-off setup
P3.8 Automatic hold setup
Sub-menu of pH parameter setting
Sub-menu of Cond. parameter setting
Sub-menu of basic parameter setting
Main menu of parameter setting