Nitzan NTZ-COMBI1 User manual

NTZ-COMBI1 Version1.6
pH/Conductivity Portable Meter
Manual
NTZ-COMBI1 Portable pH/Cond. Meter

NTZ-COMBI1 Version1.6
Table of Content
1. Introduction................................................................................................................................................ 1
1.1 Measurement parameters ................................................................................................................... 1
1.2 Basic features ...................................................................................................................................... 1
1.3 pH measurement features ................................................................................................................... 1
1.4 Conductivity measurement features .................................................................................................... 1
2. Specifications ............................................................................................................................................ 2
2.1. Main specifications ............................................................................................................................. 2
2.2. Other specifications ............................................................................................................................ 2
3. Instrument description ............................................................................................................................... 3
3.1. LC display ........................................................................................................................................ 3
3.3. Meter socket ....................................................................................................................................... 5
3.4. Reading stability display mode ........................................................................................................... 5
3.5. Automatic power-off ............................................................................................................................ 5
4. pH measurement ....................................................................................................................................... 5
4.1. pH electrode information .................................................................................................................... 5
4.2. pH calibration consideration ............................................................................................................... 6
4.3. pH meter calibration ........................................................................................................................... 8
4.4. Customer-defined calibration ............................................................................................................. 9
4.5. Sample test ......................................................................................................................................... 9
4.6. pH electrode maintenance ................................................................................................................11
5. mV value measurement: ......................................................................................................................... 12
5.1. Notes ................................................................................................................................................ 12
6. Conductivity Measurement: .................................................................................................................. 12
6.1. Conductivity electrode information ................................................................................................... 12
6.2. Conductivity calibration .................................................................................................................... 13
6.3. Conductivity calibration .................................................................................................................... 14
6.4. Customer-defined calibration ........................................................................................................... 15
6.5. Sample test ....................................................................................................................................... 15
6.6. Conductivity electrode maintenance ................................................................................................ 16
7. Parameter setting .................................................................................................................................... 16
7.1. Main menu ........................................................................................................................................ 16
7.2.Submenu ........................................................................................................................................... 17
7.3. Submenu of pH parameter setting ................................................................................................... 18
7.4. Submenu of conductivity parameter setting ..................................................................................... 19
7.5. Submenu of standard parameter setting .......................................................................................... 20
8. Meter Kits ................................................................................................................................................ 20
9. Warranty .................................................................................................................................................. 21
Appendix I: Parameter setting & Factory default setting ............................................................................ 21
Appendix II: Abbreviation Glossary ............................................................................................................. 22
Appendix III: Self-diagnosis information ..................................................................................................... 22

NTZ-COMBI1 Version1.6 1
1. Introduction
Thanks for purchasing NTZ-COMBI1 portable pH/Conductivity meter.
This meter is the 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.
1.1 Measurement parameters
Measurement
parameters NTZ-COMBI1
pH/mV √
Conductivity √
Temperature √
1.2 Basic features
● 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, probes, standard solutions and all accessories,
convenient to use in field.
● The meter is dust-proof and water-proof, meeting the IP54 rating.
● Temperature calibration function.
1.3 pH measurement features
● 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 four
options of standard buffer solution: USA series, NIST series and customer-defined solution
set-up.
● The meter provides reading stability criteria.
1.4 Conductivity measurement features
● 1-4 point automatic calibration, the meter provides calibration guide and automatic checking
function.

NTZ-COMBI1 Version1.6 2
● The meter is able to recognize up to 4 types of conductivity standard solutions. There is
customer-defined solution set-up.
2. Specification
2.1. Main specifications
Specifications
pH
Range （0.00 ~ 14.00）pH
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 ±1,000mV
Resolution 1mV
Accuracy ±0.1% FS ±1digit
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
Resolution 0.1/1µS/cm 0.01/0.1 mS/cm
Accuracy ±1.0% FS ±1digit
Temperature
compensation （0 ~ 80）℃（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
Temperature
Range 0~100°C
Resolution 0.1℃
Accuracy ±0.5℃±1digit
Reading tability criteria Low:1.2mV/10 sec., Medium:0.6mV/10 sec.,
High:0.3mV/10 seconds
2.2. Other specifications:
Power AAA batteries × 3 (1.5V× 3)

NTZ-COMBI1 Version1.6 3
IP rating IP54
Dimen ion &
Weight Meter: (86×196×33 )mm / 335g
3. In trument de cription
3.1. LC display：
(1) — Parameter mode icons
(2) — Measurement reading
(3) — Prompts of special display mode
(4) — Units of measurement
(5) — Temperature units (°C and °F)
(6) — Units of pH and conductivity calibration value（appears with (7)）
(7) — pH and conductivity calibration value（appears with (6)）, and prompts of special display mode
(8) — Temperature value（appears with (5)）, and prompts of special display mode
(9) — Temperature compensation icons
ATC — automatic temperature compensation, MTC — manual temperature compensation
(10) — Calibration guide icon
(11) — Stability icon of readings
(12) — Low battery icon, when this icon appears, please renew the battery
iagram-1

NTZ-COMBI1 Version1.6 4
3.2. Keypad func ions
3.2.1. Keypad operations
Momentary press ----- <1.5 seconds , Long press ----- >1.5 seconds.
3.2.2. Turn on the meter
Press to turn on the meter: LC full display → display some parameters → display the last
measurement mode.
3.2.3. 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, pressing is invalid. Please press
CAL/M AS key to return to the measurement mode, then press to turn off the meter.
Chart -1 Keypad operations and descriptions
Keypad
Operations escriptions
Momentary press
● In the power-off mode, press this key to turn on the meter.
Long press
● In the measurement mode, press and hold this key for 2 seconds to
turn off the meter.
Momentary/long
press
●COMBI1 pH/Conductivity meter: press this key to select
measurement mode: pH → mV → CON
● In the mode of manual temperature compensation (MTC), when
press and hold this key, the temperature value flashes, then press
this key to change the temperature value (only one direction), and
press to confirm.
● In the parameter set-up mode, press this key to change the serial
number of the main menu and the submenu (only one direction).
● In the submenu mode, press this key to change parameters and
set-up (only one direction).
iagram-2

NTZ-COMBI1 Version1.6 5
Momentary press
● In the measurement mode, press this key to enter in the calibration
mode.
● In the calibration mode or the parameter set-up mode, 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 make calibration.
● In the parameter set-up mode, press this key to select programs.
3.3. Meter socket
Electrode socket uses BNC and RCA.
Chart-2 Sockets for Meters
Models Photos escription
NTZ-COMBI1 pH/Conductivity
meter
•BNC socket (right) —
connect pH
electrode or ORP electrode,
•BNC socket(left) — connect
conductivity electrode,
•RCA socket (middle) — connect
temperature probe
3.4. Reading stability display mode
When the measuring value is stable, smiley icon appears on LC ,
see iagram – 3. 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.
Per parameter P1.6, there are 3 criteria for stability standard:
(Normal), (High) and (Low). The factory default is set
“Normal”.
“High” is set for stability for longer time, “Low” is set for stability for shorter
time. User can select suitable stability criteria according to different testing
requirement.
3.5. Automatic power-off
The meter will be power-off after the meter stops operation for 20 minutes.
4. pH mea urement
4.1. pH electrode information
The meter matches plastic pH electrode. Electrode housing adopts polycarbonate engineering plastics
which is corrosion and impact resistant. Connect the electrode to the BNC socket. When dip the
iagram- 3

NTZ-COMBI1 Version1.6 6
electrode in the solution, please stir the solution briefly and allow it to stay in the solution until a stable
reading is reached.
4.2. pH calibration consideration
4.2.1. Standard buffer solution
The meter uses two series of standard buffer solution: USA series and NIST series, and also
customer-defined solution. Please see Chart - 3 for the two series of standard buffer solution. For
customer-defined solution, please select it per parameter P1.1 and refer to clause 7.3 for details.
Chart - 3 pH standard buffer solution series
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
4.2.2. Three-point calibration
The instrument can perform 1-3 point calibration. The first point calibration must use 7.00 pH (or 6.86 pH)
standard solution, then select other standard solution to perform the second and the third point calibration.
See chart – 4. uring the calibration process, the instrument displays the electrode slope of acidity range
and alkalinity range respectively.
Chart - 4 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 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
4.2.3. Calibration intervals
Calibration intervals depend on the sample, the electrode performance, and the required accuracy. For
high accuracy measurements (≤ ±0.02pH), the meter should be calibrated immediately before taking a
measurement. For general accuracy (≥±0.1pH), the meter can be calibrated and used for approximately
one week before the next calibration.
The meter must be recalibrated in the following situations:

NTZ-COMBI1 Version1.6 7
(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

NTZ-COMBI1 Version1.6 8
4.3. pH meter calibration ( take an example of three-point calibration)
4.3.1. Press key to enter into the calibration mode, “CAL 1”
blinks at the top right of LC and “7.00 pH ”blinks at the bottom right of
LC , indicating using pH 7.00 buffer solution to make the 1st point calibration.
4.3.2. Rinse pH electrode in pure water, allow it to dry, and submerge it in
pH7.00 buffer solution. Stir the solution briefly and allow it to stay in the
buffer solution until a stable reading is reached. The meter’s display will
show scanning and locking process of calibration buffer solution at the
bottom right of LC . Er 2 displays if press key before the value
is locked. See chart – 5.
4.3.3. When the meter locks 7.00 pH, stable icon displays on LC .
Press key to calibrate the meter. End icon appears after
calibration is done. The 1st point calibration is finished, meanwhile,
the meter’s display will show at the top right a blinking CAL2, and show at the
bottom right blinking 4.00pH and 10.01pH alternately, indicating using
pH4.00 or pH10.01 buffer solution to make the 2nd point calibration.
4.3.4. Take out pH electrode，rinse it in pure water, allow it to dry, and
submerge it in pH4.00 buffer solution. Stir the solution briefly and allow it to
stay in the buffer solution until a stable reading is reached. The meter’s
display will show scanning and locking process of calibration buffer solution
at the bottom right of LC . When the meter locks 4.00 pH, stable icon
displays on LC . Press key to calibrate the meter. End icon and
electrode lope of acidity range display after calibration is done, meanwhile,
the meter’s display will show at the top right a blinking CAL3, and show at the
bottom right blinking 10.01pH, indicating using pH10.01 buffer solution to make
the 3rd point calibration.
4.3.5. Take out pH electrode，rinse it in pure water, allow it to dry, and
submerge it in pH10.01 buffer solution. Stir the solution briefly and allow it to
stay in the buffer solution until a stable reading is reached. The meter’s display
will show scanning and locking process of calibration buffer solution at the
bottom right of LC . When the meter locks 10.01 pH, stable icon displays
on LC .
Press key to calibrate the meter. End icon and electrode lope of
alkalinity range display after calibration is done. The meter goes to the
measurement mode, displays stable measuring value and calibration guide icons.
Please see iagram – 4 for the above calibration process.
4.3.6. uring 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 LC .
iagram- 4

NTZ-COMBI1 Version1.6 9
4.4. Customer-defined calibration (take an example of 1.60pH and 6.50pH calibration solution)
4.4.1. Select CUS per parameter P1.1 (please refer to clause 7.3 for customer-defined solution). The
meter enters into Customer-defined calibration mode. Press key, the meter’s display shows a blinking
CAL1 icon at the top right of LC , indicating the meter enters into the 1st point customer-defined
calibration.
4.4.2. Rinse pH electrode in pure water, allow it to dry, and submerge it in pH1.60 buffer solution. Stir the
solution briefly and allow it to stay in the buffer solution until a stable reading is reached. For automatic
temperature compensation (ATC), the temperature value does not blink. When press key, the main
value blinks. Press key to adjust the main value to 1.60, then press key to calibrate the meter.
After calibration is done, LC 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 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.
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. For automatic
temperature compensation (ATC), the temperature value does not blink. When press key, the main
value blinks. Press key 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. For customer-defined calibration,
LC does not show electrode calibration guide icons.
Note: For manual temperature compensation (MTC), when LCD displays the stable measuring
value and icon, press key, then the temperature value blinks, press 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.
4.4.4. Notes
(a) The meter can perform 1-2 point customer-defined calibration. When the 1st point calibration is done,
press key, the meter exits from calibration mode. This is one-point customer-defined calibration.
(b) The value set in “Customer-defined” is at a fixed 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.
4.5. Sample test
4.5.1. 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 LC and a stable reading is
reached which is pH value of tested solution.

NTZ-COMBI1 Version1.6 10
iagram – 5 is the calibration and measurement process of pH meter
iagram – 5 Calibration and measurement process of pH meter
4.5.2. Self-diagnosis information
uring the process of calibration and measurement, the meter has self-diagnosis functions, indicating the
relative information as below, please refer to chart – 5.
Chart – 5 Self-diagnosis information of pH measurement mode
isplay 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
uring 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
（<0.00 pH or >14.00pH）
1.Check whether the electrode is suspended.
2.Check whether the meter connects the
electrode well.
3.Check whether the electrode is damaged
Sample
test
1
st
point calibration
2
n
d
point
calibration
3
r
d
point calibration
After the 1
st
point
calibration is done,
press key to enter
into the measurement
mode.
After the 2
nd
point
calibration is done,
press key to enter
into the measurement
mo
de
.
After the 3
rd
point
calibration is done, the
meter enters into the
measurement mode
automatically.
Submerge the electrode
in pH7.00 solution,P
ress
key when icon
appears
.
Submerge the electrode
in pH4.00 solution, press
key when icon
appears
.
Submerge the electrode
in pH10.01solution,
press
key when icon
appears.
Press key to enter
into the calibration
mode.
Press to turn on
on the meter.

NTZ-COMBI1 Version1.6 11
4.5.3. pH temperature principle
The closer the temperature of the sample solution to the calibration solution, the more accurate readings.
4.5.4. Factory default setting
For factory default setting, please refer to parameter P1.5 (Item 7.3). 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 that once set the factory default, all the data deleted will not be retrievable.
4.6. pH electrode maintenance
4.6.1. aily 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.
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
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. The electrode should be
thoroughly cleaned if a sample sticks to the electrode. Use a solvent if the solution does not appear clean
after washing.
4.6.4. Renew glass bulb
Electrodes that have been used over a long period of time, will become ageing. Submerge the electrode in
0.1mol/L hydrochloric acid for 24 hours, then wash the electrode in pure water, then submerge it in
soaking solution for 24 hours.
The method to prepare 0.1mol/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 (please refer to Chart-6)
Chart – 6 Clean contaminated glass bulb and junction
Contamination Abluent
Inorganic metal oxide ilute acid less than 1mol/L

NTZ-COMBI1 Version1.6 12
Organic lipid ilute detergent (weak alkaline)
Resin macromolecule ilute alcohol, acetone, ether
Proteinic haematocyte sediment Acidic enzymatic solution (saccharated yeast tablets)
Paint ilute bleacher, peroxide
Note: The electrode housing is polycarbonate. When use abluent, take cautions on carbon
tetrachloride, trichlorethylene, tetrahydrofuran, acetone, etc which will dissolve the housing and
invalidate the electrode.
5. mV value mea urement:
Press key, and switch the meter to mV measurement mode. Connect ORP electrode (included) 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.
5.1. 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 polluted which
causes inaccurate measurement and slow response. Please refer to the following methods to clean and
activate ORP electrode:
(a) For inorganic pollutant, submerge the electrode in 0.1mol/L dilute hydrochloric acid for 30 minutes,
then wash it in pure water, then submerge it in the soaking solution for 6 hours.
(b) For organic or lipid pollutant, clean the platinum surface with detergent, then wash it in pure water, then
submerge it in the soaking solution for 6 hours.
(c) For heavily polluted platinum surface on which there is oxidation film, polish the platinum surface with
toothpaste, then wash it in pure water, then submerge it in the soaking solution for 6 hours.
6. Conductivity Mea urement:
6.1. Conductivity electrode information
6.1.1. Conductivity electrode
Plastic conductivity electrode with constant K=1.0 and built-in temperature sensor, can realize automatic
temperature compensation. The electrode housing is polycarbonate plastic which is corrosion resistant
and impact resistant. BNC jack of electrode connects to the meter’s conductivity input jack, RCA jack
connects temperature jack. When submerge the conductivity electrode in solution, stir the solution briefly
to eliminate the air bubbles and improve response and stability.
6.1.2. Conductivity electrode constant

NTZ-COMBI1 Version1.6 13
The meter matches conductivity electrodes of three constants: K=0.1, K=1.0 and K=10.0. Please refer to
chart-7 for measuring range. Set constant per parameter P2.1 and refer to clause 7.4.
Chart – 7 Electrode constant and measuring range
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
6.2. Conductivity calibration
6.2.1. 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 LC correspond to the four standard values.
See chart – 8:
Chart – 8 Conductivity standard solution series
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
6.2.2. Calibration intervals
(a) The meter is calibrated before leaving the factory and can generally be used right out of the box.
(b) Normally perform calibration per month.
(c) For high accuracy measurements or large temperature deviation 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 error.
(e) 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.
6.2.3 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

NTZ-COMBI1 Version1.6 14
concentration being contaminated.
6.2.4. 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 and see clause 7.4.
6.2.6. Temperature coefficient
The temperature compensation coefficient of the meter setting is 2.0%. However, the conductivity
temperature coefficient is different for solutions of a different variety and concentration. Please refer to
chart – 9 and the data collected during testing. Set per parameter P2.6. and see clause 7.4.
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.
Chart -9 Temperature compensation coefficient of special solutions
Solution Temperature compen ation coefficient
NaCl solution 2.12%/°C
5% NaOH solution 1.72%/°C
ilute ammonia solution 1.88%/°C
10% hydrochloric acid solution 1.32%/°C
5% sulfuric acid solution 0.96%/°C
6.2.7. 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.
6.3. Conductivity calibration (take an example of calibration with 1413µS/cm)
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 “ td” 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 locked. See chart – 10.
6.3.3. When the meter locks 1413 µS, stable icon displays on LC .

NTZ-COMBI1 Version1.6 15
Press key to calibrate the meter. End icon appears after
calibration is done. The meter returns to the measurement mode
and LC shows icon at the bottom left. See iagram – 6 for the above
calibration process.
6.3.4. If return from calibration mode without calibration, press key to
return to the measurement mode without calibration.
6.3.5. For multi-point calibration, please repeat clause 6.3.1-6.3.3 until all
the calibration is done. The meter can repeat calibration in the same
calibration
solution until the stable value is reached.
6.4. Customer-defined calibration (take an example of 10.50µS/cm standard
solution)
6.4.1. Select CUS per parameter P2.2 (please refer to clause 7.4 for
customer-defined solution). The meter enters into customer-defined
calibration mode. When press , LC shows blinking CUS at the top right,
indicating that the meter enters into customer-defined calibration.
6.4.2. Rinse the electrode in pure water, allow it to dry, and submerge it in 10.50 µS/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 LC .
6.4.3. When press key, the measuring value blinks. “CUS” icon appears at the right top of the screen.
Press key to adjust the measuring value to 10.50 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. For
customer-defined calibration, the electrode calibration guide icons do not appear in conductivity
measurement mode.
Note: When there is no temperature sensor and manual temperature compensation (MTC) is adopted, the
temperature value blinks when press key, press key to adjust the temperature value, and when
press key, conductivity value blinks.
6.4.4. 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.
6.5. Sample test
6.5.1. 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 LC , then get the reading value which is the conductivity value of the solution.
iagram- 6

NTZ-COMBI1 Version1.6 16
6.5.2. uring the process of calibration and measurement, the meter has self-diagnosis functions,
indicating the relative information as below: chart – 10.
Chart – 10 Self-diagnosis information of conductivity measurement mode
isplay 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
uring 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.
6.5.3 Factory default setting
For factory default setting, please refer to parameter P2.8 (Item 7.4). Per 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.
6.6. Conductivity electrode maintenance
6.6.1. 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 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.
6.6.2. The interaction pole of Model 2301T-F conductivity electrode is coated with platinum black to
minimize electrode polarization and expand measuring range. o not polish the surface of platinum black,
only stir the electrode in pure water to avoid damage of the platinum black coating. Clean organic stain on
the electrode in warm water with detergent, or alcohol.
6.6.3. 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.
7. Parameter etting
7.1. Main menu
In the measurement mode, press key to enter in P1.0, then press to switch to main menu:
P1.0→P2.0→P6.0. Please refer to chart – 7.

NTZ-COMBI1 Version1.6 17
P1.0: pH parameter setting menu,
P2.0: Conductivity parameter setting menu,
P6.0: Basic parameter setting menu.
7.2.Submenu
7.2.1. In P1.0 mode, press key to enter in submenu P1.1 of pH parameter setting, then press
key to switch among submenu: P1.1→P1.4→P1.6, see iagram – 7.
7.2.2. In P2.0 mode, press key to enter in submenu P2.1 of conductivity parameter setting, then
press key to switch among submenu: P2.1→P2.2→P2.5→P2.6, see iagram– 7.
7.2.3. In P6.0 mode, press key to enter in submenu P6.1 of basic parameter setting, see iagram –
7.
iagram – 7 Main menu and submenu of parameter setting
P1.1 Select pH standard solution
P1.4 Select resolution
P1.5 Restore to factory setting
P1.6 Set stability criteria
P1.7 Temperature calibration
P2.1 Select electrode constant
P2.2 Select conductivity standard solution
P2.5 Select reference temp.
P2.6 Adjust temperature
compensation factor
P2.8 Res ore o fac ory se up
P2.9 Tempera ure calibra ion
P6.1 Select temperature unit
P6.8 Automatic power-off setup
Submenu of pH parameter setting
Submenu of
Cond.
pa
rameter setting
Submenu of basic parameter setting
Main menu of parameter setting

NTZ-COMBI1 Version1.6 18
7.3. Submenu of pH parameter setting (press key to switch)
P1.1
.
–
Select pH tandard olution (USA
-
NIST
-
CUS)
1. In P1.0 mode, press to enter in P1.1, refer to the left iagram.
2. When press key, USA blinks, press key to select blinking
NIST→CUS. When parameter blinks, press to confirm ( USA
series: 1,68 pH, 4.00 pH, 7.00 pH, 10.01 pH, NIST series: 1,68 pH,
4.01 pH, 6.86 pH, 9.18 pH, CUS – customer-defined).
3. After confirm parameter, press key to enter in P1.4 mode, or
press key to return to the measurement mode.
P1.4. – Select re olution (0.01 – 0.1)
1. Press key, 0.01 blinks, press key, 0.1 blinks, when
parameter blinks, press key to confirm.
2. After confirm parameter, press key to enter in P1.6 mode, or
press to return to the measurement mode.
P1.5. – Re tore factory etting (No – Ye )
1. Press key, No blinks, press key, Yes blinks, press
key to confirm, the meter returns to the measurement mode.
No – o not restore, Yes – Restore to factory setting.
2. Press key to enter in mode P1.6, or press key to return to
the measurement mode.
P1.6. – Set reading tability criteria (Normal – High – Low)
1. Press key, nor blinks. Press key, Hi blinks, then press
key, Lo blinks. When parameter blinks, press to confirm.
Nor – Normal, Hi – High, Lo – Low.
2. Press key to enter in mode P1.7, or press to return to the
measurement mode.
P1.7. – Temperature Calibration ( Calibration range ±5℃)
1. Press key, the temperature value blinks, press key to
adjust the temperature value, press key to confirm.
2. When parameter is confirmed, press key to return to the
measurement mode.
Note: When make calibration, insert the temperature probe in the
standard temperature source (eg. thermostatic bath) and calibrate until
the display value is stable. The calibration range is ±5℃. When set up
“Yes” in P1.5, the temperature value restores to factory setting.