GHM Delta OHM HD2106.1 User manual

Operating manual
Conductivity
meters/thermometers
HD2106.1
– HD2106.2
www.deltaohm.com
English
Keep for future reference.

HD2106 - 2 - V2.4
CONTENTS
INTRODUCTION ........................................................................................................................................................3
KEYBOARD AND MENU DESCRIPTION.........................................................................................................8
CONDUCTIVITY MEASUREMENT....................................................................................................................16
COMPENSAZIONE AUTOMATICA O MANUALE DELLA CONDUCIBILITA’......................................................................18
CALIBRATION OF CONDUCTIVITY...............................................................................................................................18
AUTOMATIC CALIBRATION OF CONDUCTIVITY USING MEMORIZED STANDARD SOLUTIONS...................................19
MANUAL CALIBRATION OF CONDUCTIVITY USING NON MEMORIZED STANDARD SOLUTIONS................................20
TABLE OF STANDARD SOLUTIONS AT 147 µS/CM,1413 µS/CM,12.88 MS/CM AND 111.8 MS/CM..............................21
DIRECT INPUT INTO PT100 AND PT1000 TEMPERATURE PROBES ........................................................................22
HOW TO MEASURE ......................................................................................................................................................22
INSTRUCTIONS TO CONNECT THE TP47 MODULE FOR CONDUCTIVITY/TEMPERATURE COMBINED PROBES,
4-WIRE PT100 PROBES,AND 2OR 4-WIRE PT1000 PROBES..........................................................................22
WARNINGS AND OPERATING INSTRUCTIONS .....................................................................................26
NOTES ON CONDUCTIVITY PROBES............................................................................................................................27
INSTRUMENT SIGNALS AND FAULTS .........................................................................................................28
LOW BATTERY WARNING AND BATTERY REPLACEMENT ...............................................................30
INSTRUMENT STORAGE......................................................................................................................................32
SERIAL INTERFACE AND USB .........................................................................................................................33
STORING AND TRANSFERRING DATA TO A PC.....................................................................................35
THE LOGGING FUNCTION –ONLY FOR HD2106.2.................................................................................................35
CLEARING THE MEMORY –ONLY FOR HD2106.2 ...................................................................................................35
THE PRINT FUNCTION.................................................................................................................................................36
CONNECTION TO A PC.........................................................................................................................................37
CONNECTION TO THE RS232C SERIAL PORT OF THE INSTRUMENT.......................................................................37
COLLEGAMENTO ALLA PORTA USB 2.0 DELLO STRUMENTO -SOLO PER HD2106.2..........................................37
NOTE SUL FUNZIONAMENTO E LA SICUREZZA OPERATIVA .........................................................38
INSTRUMENT TECHNICAL CHARACTERISTICS .....................................................................................39
TECHNICAL DATA OF PROBES WITH MODULE IN LINE WITH THE INSTRUMENT.......................................................42
Pt100 OR Pt1000 PROBES COMPLETE WITH TP47 MODULE............................................................................42
2AND 4-ELECTRODE CONDUCTIVITY PROBES .....................................................................................................42
ORDERING CODES .................................................................................................................................................43

HD2106 - 3 - V2.4
INTRODUCTION
The HD2106.1 and HD2106.2 are portable instruments with a large LCD display.
They measure conductivity, liquid resistivity, total dissolved solids (TDS) and salinity
using combined 4-ring and 2-ring conductivity/temperature probes. Temperature only
is measured by Pt100 or Pt1000 immersion, penetration or contact probes.
The probe calibration can be performed automatically in one or more of the 147
µS/cm, 141 3µS/cm, 12880 µS/cm or 111,800 µS/cm conductivity calibration solu-
tions.
The temperature probes are automatically detected by the instrument upon turning
on.
The HD2106.2 is a datalogger. It memorizes up to 36,000 conductivity and tempera-
ture samples that can be transferred from the instrument connected to a PC via the
RS232C serial port or USB 2.0 port. The storing interval, printing, and baud rate can
be configured using the menu.
The HD2106.1 and HD2106.2 models are fitted with an RS232C serial port and can
transfer the acquired measurements to a PC or to a portable printer in real time.
Display, printing and logging (model HD2106.2) always include temperature in °C or
°F, and one of the parameters of conductivity measure (χ or Ω or TDS or NaCl).
The Max, Min and Avg function calculates the maximum, minimum or average values.
Other functions include the relative measurement REL, the Auto-HOLD function, and
the automatic turning off which can also be disabled.
The instruments have IP66 protection degree.
This manual describes the HD2106.1 and HD2106.2 models: if not otherwise
specified, the description is intended to be applicable to both models.

HD2106 - 4 - V2.4
Conductivity meter – Thermometer
HD2106.1

HD2106 - 5 - V2.4
HD2106.1
1. 8-pole DIN45326 connector, input for combined 4-ring or 2-ring conductivi-
ty/temperature probes, for direct 4-wire Pt100 temperature probes and 2 or
4-wire Pt1000 probes complete with TP47 module.
2. External auxiliary power supply connector input (positive at centre).
3. Battery symbol: displays the battery charge level.
4. Function indicators.
5. Secondary display line.
6. CAL/key: during normal operation starts the conductivity probe calibration; in
the menu, increases the current value.
7. FUNC/ENTER: key: during normal operation displays the maximum (MAX), the
minimum (MIN) and the average (AVG) of current measurements; in the menu,
confirms the current selection. This updates the display measurement when the
Auto-Hold function is enabled.
8. REL/: key: enables the relative measurement (displays the difference between
the current value and the logged value when the key is pressed); in the menu,
decreases the current value.
9. SERIAL key: starts and ends the data transfer to the serial communication port.
10. MENU key: allows access to and exit from the menu.
11. χ-Ω-TDS/ESC key: changes the main variable measurement between conductivi-
ty, resistivity, total dissolved solids (TDS) and salinity. In the menu, cancels the
operation in progress without making changes.
12. °C/°F key: when the probe is not connected, allows manual modification of the
temperature. When the probe is connected, if this key is pressed twice, it changes
the unit of temperature measurement from degrees Celsius to Fahrenheit.
13. ON-OFF/AUTO-OFF key: turns the instrument on and off; when pressed togeth-
er with the CAL key, disables the automatic turn off.
14. MAX, MIN and AVG symbols.
15. Main display line.
16. Line for symbols and comments.
17. 8-pole MiniDin connector for RS232C. For the connection to PC (with cable
HD2110CSNM or C206) or printer (with cable HD2110CSNM).

HD2106 - 6 - V2.4
Conductivity meter – Thermometer
HD2106.2

HD2106 - 7 - V2.4
HD2106.2
1. 8-pole DIN45326 connector, input for combined 4-ring or 2-ring conductivi-
ty/temperature probes, for direct 4-wire Pt100 temperature probes and 2 or
4-wire Pt1000 probes complete with TP47 module.
2. External auxiliary power supply connector input (positive at centre).
3. Battery symbol: displays the battery charge level.
4. Function indicators.
5. Secondary display line.
6. CAL/key: during normal operation starts the conductivity probe calibration; in
the menu, increases the current value.
7. FUNC/ENTER key: during normal operation displays the maximum (MAX), the
minimum (MIN) and the average (AVG) of current measurements; in the menu,
confirms the current selection. This updates the display measurement when the
Auto-Hold function is enabled.
8. REL/key: enables the relative measurement (displays the difference between
the current value and the logged value when the key is pressed); in the menu,
decreases the current value.
9. SERIAL/ERASE LOG key: starts and ends the data transfer to the serial commu-
nication port. In the menu, clears the data contained in the instrument's memory.
10. LOG/DUMP LOG key: during normal operation, starts and ends the saving of the
data in the internal memory; in the menu, starts the data transfer from the in-
strument's memory to the PC.
11. Mini-USB type B connector for USB 2.0. For the connection to PC (with cable
CP23).
12. MENU key: allows access to and exit from the menu.
13. χ-Ω-TDS/ESC key: changes the main variable measurement between conductivi-
ty, resistivity, total dissolved solids (TDS) and salinity. In the menu, cancels the
operation in progress without making changes.
14. °C/°F key: when the probe is not connected, allows manual modification of the
temperature. When the probe is connected, if this key is pressed twice, it changes
the unit of temperature measurement from degrees Celsius to Fahrenheit.
15. ON-OFF/AUTO-OFF key: turns the instrument on and off; when pressed togeth-
er with the CAL key, disables the automatic turn off.
16. MAX, MIN and AVG symbols.
17. Main display line.
18. Line for symbols and comments.
19. 8-pole MiniDin connector for RS232C. For the connection to PC (with cable
HD2110CSNM or C206) or printer (with cable HD2110CSNM).

HD2106 - 8 - V2.4
KEYBOARD AND MENU DESCRIPTION
Foreword
The instrument keyboard is composed of single-function keys, like the MENU key, and
double-function keys such as the ON-OFF/Auto-OFF key.
In the double-keys, the function in the upper part is the "main function", while the
one in the bottom part is the "secondary function". When the instrument is in stan-
dard measurement mode, the main function is active. In the menu or in conjunction
with the FUNC key, the secondary function is enabled.
The pressing of a key is accompanied by a short confirmation beep: a longer beep
sounds if the wrong key is pressed.
Each key specific function is described in detail below.
ON-OFF/Auto-OFF key
The instrument is turned on and off using the ON/OFF key. Turning on enables all dis-
play segments for a few seconds, starts an auto-test, and displays the current values
of cell constant (CELL) and temperature coefficient α(ALPH). Finally, it sets the in-
strument ready for normal measurement.
MIN
cm
min s
2
3
mµ
m
k
>>>
During turning on, should no probes be connected, the last manually-set
temperature appears in the secondary line. The unit of measurement symbol
(°C or °F) starts blinking, and a letter "m" meaning "manual" appears next to
the battery symbol.
The probe's data are captured upon turning the instrument on: if the ERR
message appears in the secondary line, it is necessary to turn the instrument
off and then on again.
Replace the probes when the instrument is off.
+ Automatic turning off
The instrument has an AutoPowerOff function that automatically turns the instrument
off after about 8 minutes if no key is pressed during the intervening time. The Auto-
PowerOff function can be disabled by holding the CAL/key pressed down when turn-
ing the instrument on: the battery symbol will blink to remind the user that the in-
strument can only be turned off by pressing the <ON/OFF> key.

HD2106 - 9 - V2.4
The automatic turning off function is disabled when external power is used.
On the other hand, it cannot be disabled when the batteries are discharged
FUNC/ENTER key
During normal measurement this enables the display and logging of the maximum
(MAX), minimum (MIN) and average (AVG) value of the conductivity, liquid resistivity,
total dissolved solids, salinity and temperature measurements, updating them with
the acquisition of new samples. The acquisition frequency is once a second. Use the
χ.Ω.TDS-ESC key to switch from conductivity to liquid resistivity, to total dissolved
solids or to salinity.
In the menu, the ENTER key confirms the current parameter and then goes to the
next one.
The MAX, MIN and AVG measurements remain in the memory until the instrument is
on, even after exiting the calculation function. To reset the previous values and restart
with a new measurement session, press FUNC until the message "FUNC CLR" appears,
then use the arrows to select YES and confirm using ENTER.
The conductivity (or resistivity or total dissolved solids or salinity) and tem-
perature values are displayed at the same time. According to settings in the
"RCD Mode" menu item, the maximum, minimum and average indications ha-
ve different meanings: please see the description of this MENU key below.
Attention: the data captured using the Record function cannot be transferred
to the PC.
CAL/

key
It increases the current parameter when used in the menu; when used in measure-
ment mode, it starts the conductivity probe calibration (please see the chapter dedi-
cated to calibration on page 18).
°C/°F key
When the temperature probe is connected, the measured value is used to compensate
the conductivity measurement; the key changes the unit of measurement from de-
grees Celsius to Fahrenheit.
If the probe is not present, the compensation temperature must be entered manually:
to manually change the value shown in the display lower line, press °C/°F once. The
temperature indicated starts blinking. While the display is blinking, it is possible to
change the compensation temperature using the arrows (and ). Confirm using
Enter. The display stops blinking, and that temperature is used for compensation.
If the temperature probe is not present, to change the unit of measurement between
°C and °F, it is necessary to press twice the °C/°F key.

HD2106 - 10 - V2.4
χ.Ω.TDS (conductivity - resistivity - total dissolved solids - salinity) / ESC
key
Changes the main variable measurement between conductivity, resistivity, total dis-
solved solids (TDS) and salinity. The selected parameter is used for display, printing
and logging (model HD2106.2).
The instrument has an Auto-Hold function, which can be set in the MENU, that "freez-
es" the measurement automatically when it has been stable (within 1 digit) for over
10 seconds: the message HOLD is displayed.
To perform a new measurement, it is necessary to press the FUNC/ENTER key.
The HOLD message starts blinking, while the display follows the actual measurement
trend, until it stabilizes again and the HOLD message remains still.
In the menu, the key clears or cancels the active function (ESC).
REL/

key
In measurement mode, it displays the difference between the current value and that
measured on pressing the key. The REL message appears on the display; press the
key again to return to the current measurement.
When used in the menu, it decreases the current variable value.
MENU key
The first menu item is accessed by initially pressing on the MENU key; press ENTER to
go to the following items. To modify the item displayed, use the arrow keys (and
). The current value is confirmed by pressing the ENTER key and the display moves
on to the next parameter. If pressing ESC the setting is cancelled.
To exit the menu, press the MENU key at any time.
The menu items are listed in this order:
1) Management of memorized data (only HD2106.2): the message
">>>_LOG_DUMP_or_ERAS" (Transfer data or erase) is scrolled in the
comment line. The center figure reports the number of free memory pages
(FREE). Pressing SERIAL/EraseLOG permanently erases all memory data. By
pressing LOG/DumpLOG, the data transfer of the logged data on the serial port
is started: the "BAUD-RATE" must have previously been set to the maximum
value (please see the menu items described below and the paragraph "STOR-
ING AND TRANSFERRING DATA TO A PERSONAL COMPUTER" on page 35).
2) Print and log interval: sets the interval in seconds between two loggings or
data transfers to the serial port. The interval can be set at 0, 1s, 5s, 10s, 15s,
30s, 60s (1min), 120s (2min), 300s (5min), 600s (10min), 900s (15min),
1200s (20min), 1800s (30min) and 3600s (1hour). If the value 0 is set, SE-
RIAL works on command: the sending of data to the serial port is per-

HD2106 - 11 - V2.4
formed each time the key is pressed. Recording (LOG) is performed with
one-second intervals even if the interval is set to 0. With an interval from 1 to
3600s, continuous data transfer is started when the SERIAL key is pressed. To
end the recording (LOG) and continuous data transfer operations (SERIAL with
an interval greater than 0), press the same key again.
3) Sleep_Mode_LOG (Automatic turning off during recording) (only
HD2106.2): this function controls the instrument's automatic turning off dur-
ing logging, occurring between the capture of a sample and the next one. When
the interval is lower than 60 seconds, the instrument will always remain on.
With intervals greater than or equal to 60 seconds, it is possible to turn off the
instrument between loggings: it will turn on at the moment of sampling and will
turn off immediately afterwards, thus increasing the battery life. Using the ar-
rows select YES and confirm using ENTER in order to enable the automatic
turning off, select NO and confirm to disable it and keep the instrument on con-
tinuously.
Note: even if Sleep_Mode_LOG=YES is selected, the instrument does not
turn off for less than one minute intervals.
4) Identifier of the sample being measured: it is an automatically increased
progressive number associated with the single PRINT function (print interval
set to 0) for the printing of labels. The index appears in the single sample
printing together with date, time, conductivity (liquid resistivity, total dissolved
solids or salinity) and temperature measured values. This menu item allows the
value of the first sample to be set: each time the PRINT key is pressed, the
identification ID in the printing is increased by 1 allowing progressive meas-
urement of all measured samples. If the Auto-Hold function, described below in
this chapter, is enabled, the print time interval is forced to zero. Pressing SERI-
AL only causes the print to occur when the measurement has stabilized (HOLD
symbol still). Later, it is possible to repeat the print at will, but while the hold
mode is on, the sample identifier number is not increased. This is useful when
more labels must be printed with the same identification code without increas-
ing the code each time.
The message "SMPL ID UNT=RSET SER=PRNT" is scrolled in the comment line:
using the arrows (and ) the currently measured sample identifier value can
be changed.
By holding the °C/°F key down the proposed number is rapidly set to zero.
The instrument's heading information will be printed using the SERIAL key.
5) AUTO-HOLD function: the instrument normally operates in continuous view
mode (default setting). In this mode the displayed measurement is updated
every second. If the Auto-Hold function is enabled, the instrument performs the
measurement and when it stabilizes it goes in HOLD mode. To update the dis-
play indication, press FUNC/ENTER.
In the following figure you can see an example of the measurement process
with the Auto-Hold function enabled. A probe is immersed into a liquid at con-
ductivity χ1and, to perform the measurement, the FUNC/ENTER key is pressed:
The conductivity measurement raises progressively reaching the final value.
The HOLD symbol blinks. In the stretch indicated by 1, the measurement re-
mains stable for 10 seconds, within two digits: at the end of this interval (point
2), the instrument goes into HOLD mode, presenting the final stable value.

HD2106 - 12 - V2.4
2 digit
10s
t
χ
χ
1
6) K CELL (Cell constant): sets the conductivity probe's cell constant nominal
value. The values 0.01, 0.1, 0.7, 1.0 and 10 cm-1 (with tolerances from –30%
to +50% of nominal value) are admitted. The cell constant must be inserted
before starting the probe calibration. An ERR signal is generated if the cell con-
stant's actual value exceeds the limits –30% or +50% of nominal value. In this
case it is necessary to check that the value set is correct, that the calibration
solutions are in good state, and then proceed with a new calibration.
The cell constant change entails resetting the calibration date: a new calibration
updates the calibration date.
7) LAST CAL m/d h/m (Last conductivity calibration): the display shows the
month and day (m/d) in the main line, and the hour and minutes (h/m) in the
secondary line of the previous calibration of the conductivity probe. This menu
item cannot be modified. The calibration year is not displayed. The cell constant
change, using the K CELL parameter, resets the date.
8) ALPH_T (Temperature coefficient αT): the temperature coefficient αTis the
percentage measurement of the conductivity variation according to temperature
and is expressed in %/°C (or %/°F). The admitted values vary from 0.00 to
4.00%/°C. Use the arrows (and ) to set the desired coefficient αT, and con-
firm with ENTER.
9) REF_TEMP (Reference temperature): it indicates the temperature to which
the displayed conductivity value is standardized and can be equal to 20°C or
25°C. Using the arrows (and ), set the desired value and confirm with EN-
TER.
10) TDS (Conversion factor χ/TDS): it represents the ratio between the meas-
ured conductivity value and the total quantity of dissolved solids in the solution,
expressed in mg/l (ppm) or g/l (ppt). This conversion factor depends on the na-
ture of the salts present in the solution: in the field of water quality treatment
and control, where the main component is CaCO3 (Calcium Carbonate), a value
of 0.5 is usually used. For agriculture water, for fertilizers preparation, and in
hydroponics, a factor of about 0.7 is used. Using the arrows (and ), set the
desired value, selecting it in the 0.4…0.8 range, and confirm with ENTER.
11) RCD MODE (Record mode): the instrument captures a conductivity and a
temperature value every second. If the RCD MODE parameter is set to "con-
ductivity" (factory default), the maximum (MAX) and minimum (MIN) values
displayed using FUNC/ENTER refer to conductivity: the indicated temperature is

HD2106 - 13 - V2.4
that measured at the maximum and minimum conductivity and is not the max-
imum and minimum temperature.
If the RCD MODE parameter is set to "tp" (=temperature), the maximum and
minimum val-ues displayed using FUNC/ENTER refer to temperature: the indi-
cated conductivity is that measured at the maximum and minimum tempera-
ture and is not the maximum and minimum conductivity.
Finally, if the RCD MODE parameter is set to "Indep" (=independent), the
maximum and minimum values displayed using FUNC/ENTER are independent:
the indicated conductivity and temperature are the maximum and minimum
measured values but are not necessarily re-ferred to the same measurement
moment.
12) Probe type: the message ">>>_PRBE_TYPE" is scrolled in the comment line.
The main line in the center of the display shows the type of temperature probe
connected to the instrument. Conductivity/temperature combined probes with
Pt100 or Pt1000 sensor, or temperature only probes can be connected to the
input:
•4-wire Pt100 using the TP47 module
•2 or 4-wire Pt1000 using the TP47 module
Upon being turned on, the instrument automatically detects the temperature
probes: the Probe Type menu item is configured by the instrument and cannot
be modified by the user. If no temperature probe or combined probe with tem-
perature sensor is connected, the instrument displays a dotted line (- - - -).
13) YEAR: to set the current year. Use the arrows to modify this parameter and
confirm using ENTER.
14) MNTH (month): to set the current month. Use the arrows to modify this pa-
rameter and confirm using ENTER.
15) DAY: to set the current day. Use the arrows to modify this parameter and con-
firm using ENTER.
16) HOUR: to set the current hour. Use the arrows to modify this parameter and
confirm using ENTER.
17) MIN: to set the current minutes. In order to correctly synchronize the minute,
it is possible to reset the seconds by pressing the °C/°F key. Use the arrows to
set the current minute plus one, and as soon as that minute is reached press
°C/°F: this synchronizes the time to the second. Press ENTER to go onto the
next item.

HD2106 - 14 - V2.4
18) BAUD_RATE: indicates the frequency used for the serial communication with
the PC. Values from 1200 to 38400 baud. Use the arrows to modify this param-
eter and confirm using ENTER. The communication between instrument
and PC (or serial port printer) only works if the instrument and PC
baud rates are the same. If the USB connection is used this parameter value
is automatically set (please see the details on page 34).
LOG/DUMP LOG key - only HD2106.2
In measurement mode, this function starts and stops the logging of a data block to be
saved in the instrument's internal memory. The data logging frequency is set in the
"Print and log interval" menu parameter. The data logged between a start and
subsequent stop represent a block.
When the logging function is on, the LOG indication is displayed, the battery symbol
blinks and a beep is issued each time a logging occurs; the battery symbol does
not appear when using an external power supply.
To end the logging, press LOG.
If the Auto-HOLD function is enabled (please see the menu), the data logging
is disabled.
The HD2106.2 can turn off during logging between one capture and the next: the
function is controlled by the Sleep_Mode_LOG parameter. When the logging interval
is less than one minute, the logging instrument remains on; with an interval of at
least one minute, it turns off between one capture and the next if the parameter
Sleep_Mode_LOG=YES.
>>>
Scarico dati (Dump LOG) - solo per HD2106.2
When the LOG key is pressed after the MENU key, the transfer of the logged data on
the serial port is started.
Please see the paragraph dedicated to data transfer on page.34.
SERIAL key - only HD2106.1
SERIAL/EraseLOG key - only HD2106.2
In measurement mode, this function starts and stops the data transfer to the RS232C
serial output.
According to the settings entered in the Print and log interval menu item, a single
sample can be printed if Print and log interval=0 or a continuous indefinite printing
of the measured data can be set up if Print and log interval=1…3600.
The printing operation is accompanied by the display of the RS232 symbol and the
blinking of the battery symbol; when using an external power supply the battery
symbol does not appear.

HD2106 - 15 - V2.4
Press SERIAL to end the continuous printing.
Before starting the printing with SERIAL, set the baud rate. To do so, select the Baud
Rate menu item and select the maximum value equal to 38400 baud by using the ar-
rows. Confirm by pressing ENTER.
The DeltaLog9 software for PC will automatically set the baud rate value during con-
nection. If you are using a different program than DeltaLog9, be sure the baud
rate is the same for both the instrument and the PC: the communication will
only work in this way.
>>>
Erase memory - only HD2106.2
When pressed after the MENU key, the SERIAL key permanently erases all the data
contained in the instrument's memory.

HD2106 - 16 - V2.4
CONDUCTIVITY MEASUREMENT
The instruments work with conductivity/temperature combined probes, 4-ring and 2-
ring, only conductivity probes, or temperature probes. The 4-wire Pt100, 2 or 4-wire
Pt1000 probes may be used for measuring temperature, which is used for the
automatic compensation of the conductivity.
The instrument obtains the following from the measurement of conductivity:
•the liquid resistivity measurement (Ω, kΩ, MΩ),
•the concentration of total dissolved solids (TDS) according to the χ/TDS
conversion factor, which can be modified using the menu,
•the salinity (NaCl quantity in the solution, expressed in g/l).
The conductivity, resistivity, TDS or salinity indication is displayed in the main line,
while the secondary line shows the temperature.
The conductivity probes must be periodically calibrated. To facilitate this operation,
four automatic calibration solutions recognized by the instrument are provided:
•0.001 Molar KCl solution (147µS/cm @25°C),
•0.01 Molar KCl solution (1413µS/cm @25°C),
•0.1 Molar KCl solution (12880µS/cm @25°C),
•1 Molar KCl solution (111800µS/cm @25°C),
User calibration of the temperature sensors is not required.
The probes are detected during turn on, and this cannot be performed when
the instrument is already on, therefore if a probe is connected and the in-
strument is on, it must be turned off and back on again.
Standard probe
The standard 4-ring conductivity/temperature combined probe has code SP06T.
A bell made of PBT delimits the cell measurement zone. A positioning key, present in
the probe's end part, orients the bell correctly when the probe is introduced. For
cleaning, simply pull the bell along the probe's axis without rotating it. It is not pos-
sible to perform measurements without this bell.
This probe's temperature measuring range is 0…+90°C.

HD2106 - 17 - V2.4
4- ring or 2- ring probes
The HD2106.1 and HD2106.2 conductivity meters use 4-ring or 2-ring probes for con-
ductivity measurement.
The 4-ring probes are preferred to measure high conductivity solutions, either over an
extended range or in presence of pollutants. The 2-ring probes operate in a shorter
measurement range but with accuracy comparable with the 4-ring probes.
The probes can be in glass or plastic: the first can work in presence of aggressive pollu-
tants, the latter are more resistant to collisions, and so more suitable for industrial use.
Cells with temperature sensor
The probes fitted with built-in Pt100 or Pt1000 temperature sensor simultaneously
measure the conductivity and the temperature: that allows automatic correction of the
effect of the latter on the solution conductivity.
Choosing the cell constant
The constant is a piece of information that characterises the cell. It depends on its ge-
ometry and is expressed in cm–1. There is no cell capable of measuring the entire con-
ductivity scale accurately enough. Consequently, cells with different constants are
used allowing exact measurements on different scales. The cell with constant K =
1cm–1 allows measurements from low conductivity up to relatively high conductivity.
The theoretical measurement cell is made of two 1 cm2metallic plates separated one
from the other by 1 cm. This type of cell has a cell constant Kcell of 1 cm–1. In es-
sence, the number, form, material and dimensions of the plates are very different
from model to model, from manufacturer to manufacturer.
The low constant K probes are preferably used for low conductivity values, the high
constant ones for high values.
The indicative measurement range is reported in the following diagram:

HD2106 - 18 - V2.4
COMPENSAZIONE AUTOMATICA O MANUALE DELLA CONDUCIBILITA’
The conductivity measurement refers to a standard temperature, called reference
temperature T_REF: that is, the instrument proposes the conductivity you would get if
the temperature were T_REF. This temperature could be 20°C or 25°C according to
the setting in the T_REF menu item.
The conductivity increase per each grade of temperature variation is a characteristic
of the solution and is indicated by the term "temperature coefficient αT": admissible
values from 0.00 to 4.00%/°C, default value 2.00%/°C.
When a combined probe with temperature sensor is present, the instrument automati-
cally applies the temperature compensation function, and proposes the measurement
using the reference temperature T_REF according to the coefficient αTon the display.
In absence of the temperature probe, the lower display shows the manually set com-
pensation temperature (default=25°C).
To point this condition out, the °C or °F symbol blinks intermittently near the temper-
ature value. On the main display an "m" (manual) is turned on near the battery sym-
bol (if on). The MT indication is printed on the print-outs. On the other hand, if the
temperature probe is present, the AT symbol appears.
To manually change the compensation temperature, press the °C/°F key once: the in-
dicated temperature value starts blinking. Select the desired temperature value by us-
ing the arrows and confirm with ENTER. The display stops blinking, and the tempera-
ture displayed is used for compensation.
To change the unit of measurement between °C and °F, press the °C/°F key twice.
CALIBRATION OF CONDUCTIVITY
The probe calibration can be carried out on one, two or three points using the stand-
ard solutions automatically detected by the instrument (automatic calibration) or oth-
er solutions with known value (manual calibration).
The new calibration deletes the data of the previous calibration. For example,
if the instrument is calibrated in 4 points and a new 1-point calibration is performed,
the instrument will be calibrated in 1 point only.
The CAL symbol will blink when the cell constant is modified using the menu (please
see the description of the K_CELL menu item on page 12).

HD2106 - 19 - V2.4
AUTOMATIC CALIBRATION OF CONDUCTIVITY USING MEMORIZED STANDARD SOLUTIONS
The instrument can recognize four standard calibration solutions:
•0.001 Molar KCl solution (147µS/cm @25°C),
•0.01 Molar KCl solution (1413µS/cm @25°C),
•0.1 Molar KCl solution (12880µS/cm @25°C),
•1 Molar KCl solution (111800µS/cm @25°C),
Using one of these solutions, the calibration is automatic; the procedure can be re-
peated with the remaining standard solutions, up to a maximum of four different
points.
The manual calibration is possible with a different conductivity solution from that used
in the automatic calibration.
The solution temperature for the automatic calibration must be between
15°C and 35°C: if the solution temperature is under 15 °C or over 35 °C, the
calibration is rejected: CAL ERR indication appears.
1. Turn the instrument on with the ON/OFF key.
2. Set the probe's cell constant by selecting it from the admitted values: 0.01, 0.1,
0.7, 1.0 or 10.0
3. Dip the conductivity meter cell in the calibration solution until the electrodes are
covered with liquid.
4. Stir the probe lightly to remove any possible air inside the measurement cell.
5. If the conductivity probe is not fitted with temperature sensor, press °C/°F and, us-
ing the arrows, enter the sample solution temperature value manually (manual set-
ting of temperature). Confirm by pressing ENTER.
6. Press the CAL key. The unit of measurement (µS/cm or mS/cm) appears on the
comment line. The central line shows the solution conductivity value at the meas-
ured temperature, or if the probe is not present, at the manually-set temperature.
In the lower line, the closest temperature compensated standard buffer value.
If the measurement is in TDS, resistivity or salinity, by pressing CAL, the
instrument goes automatically into conductivity calibration mode.
7. Press ENTER to confirm the displayed value. The cell constant nominal value
(KCELL) and the set temperature coefficient αTare displayed. Pressed repeatedly
the ENTER key allows the calibration on the point to be repeated, for example, in
order to obtain a more stable value.
8. To end the probe calibration, press χ.Ω.TDS/ESC.
9. Rinse the probe with water. If you are then going to perform low conductivity
measurements, we recommend rinsing the probe using distilled or bidistilled water.
The instrument is calibrated and ready for use.

HD2106 - 20 - V2.4
MANUAL CALIBRATION OF CONDUCTIVITY USING NON MEMORIZED STANDARD SOLUTIONS
Manual calibration is possible at any calibration solution and temperature if it is within
the instrument measurement limits and provided that you know the solution's conduc-
tivity at the temperature at which the calibration is performed. Proceed as follows:
1. Turn the instrument on with the ON/OFF key.
2. Set the probe's cell constant by selecting it from the admitted values: 0.01, 0.1,
0.7, 1.0 or 10.0
3. Dip the conductivity meter cell into a known conductivity solution until the elec-
trodes are covered with liquid.
4. Stir the probe lightly to remove any possible air inside the measurement cell.
5. Press MENU, and then FUNC/ENTER until the item ALPH appears. The temperature
coefficient αTis displayed. Note down the value displayed as it must be set again
at the end of the procedure. Set the value to 0.00. This excludes the temperature
compensation during the conductivity measurement.
6. Measure the temperature by pressing °C/°F. According to the temperature detect-
ed, determine the calibration solution conductivity using the table specifying the
conductivity according to temperature.
7. Select the conductivity measurement by pressing χ.Ω.TDS/ESC.
8. Press the CAL key. The CAL symbol is turned on. The unit of measurement (µS/cm
or mS/cm) appears on the comment line. If the calibration solution conductivity is
sufficiently close (-30% to +50%) to one of the standard solutions, the secondary
line displays the value. Otherwise it displays the calculated value according to
current settings. In the central line the solution conductivity value is indicated ac-
cording to the cell constant current settings.
9. Use the arrows to select the conductivity value determined at point 4 and confirm
using ENTER. If the ERR indication appears, see the note below.
10. The cell constant nominal value (KCELL) and the temperature coefficient αTset to
0 are displayed. Pressed repeatedly the ENTER key allows the calibration on the
point to be repeated, for example, in order to obtain a more stable value.
11. To end the probe calibration, press χ.Ω.TDS/ESC.
12. Go back to the MENU and select ALPH: re-enter the temperature coefficient as it
was before the calibration.
13. Rinse the probe with water. If you are then going to perform low conductivity
measurements, we recommend rinsing the probe using distilled or bidistilled wa-
ter.
The instrument is now calibrated and ready for use.