GHM DeltaOHM HD2305.0 User manual

Operating Manual
pH Meter / Thermometer
HD2305.0
www.deltaohm.com
English
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HD2305.0 - 2 - V1.6
SOMMARIO
GENERAL CHARACTERISTICS.................................................................................................................................3
DESCRIPTION OF THE FUNCTIONS........................................................................................................................6
THE PROGRAMMING MENU .....................................................................................................................................9
PROBES AND MEASUREMENT................................................................................................................................10
THE ELECTRODE FOR pH MEASUREMENT ........................................................................................................10
Automatic or manual pH compensation 11
How to manually change the temperature 11
pH ELECTRODE CALIBRATION.......................................................................................................................................12
Calibration procedure 12
Temperature characteristics of Delta OHM buffer solutions 14
4WIRE Pt100 AND 2WIRE Pt1000 TEMPERATURE PROBES .........................................................................................15
Temperature measurement 15
Connecting the TP47 module for the 4 wire Pt100 and 2 wire Pt1000 probes 15
Direct connection of 4 wire Pt100 sensors to a DIN45326 connector 17
WARNINGS....................................................................................................................................................................18
INSTRUMENT SIGNALS AND FAULTS ..................................................................................................................19
INSTRUMENT STORAGE...........................................................................................................................................20
Notes on pH electrodes use 20
LOW BATTERY WARNING AND BATTERY REPLACEMENT .........................................................................21
WARNING ABOUT BATTERY USE ...................................................................................................................................21
NOTES ABOUT WORKING AND OPERATIVE SAFETY.....................................................................................22
TECHNICAL CHARACTERISTICS ..........................................................................................................................23
TECHNICAL INFORMATION ON THE pH METER –THERMOMETER ..................................................................................23
INSTRUMENT PROBES AND MODULES TECHNICAL DATA ...........................................................................24
PHELECTRODES.......................................................................................................................................................24
SONDE DI TEMPERATURA..............................................................................................................................................24
TEMPERATURE PROBES PT100 SENSOR USING SICRAM MODULE....................................................................................24
Pt100 4-WIRE AND Pt1000 2-WIRE PROBES COMPLETE WITH TP47 MODULE..................................................................24
ORDERING CODES......................................................................................................................................................25

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GENERAL CHARACTERISTICS
The pH meter - Thermometer Model HD2305.0 is a portable instrument that allows measurement of
pH and redox potential (ORP) in mV.
It also measures the temperature using Pt100 or Pt1000 immersion, penetration or contact probes.
The electrode calibration can be carried out on one, two or three points at 4.01pH, 6.86pH and
9.18pH.
The temperature probes are fitted with the SICRAM automatic detection module, with the factory
calibration settings already being memorized inside.
The units of measurement for the measurable quantities are:
pH
mV
°C
°F
Using the Max, Min and Avg function of this instrument respectively obtains the maximum, mini-
mum or average values.
Other available functions are:
the relative measurement REL;
the automatic turning off which can also be disabled.

HD2305.0 - 4 - V1.6
pH meter - Thermometer
HD2305.0

HD2305.0 - 5 - V1.6
HD2305.0
1. 8-pole DIN45326 connector, input for Pt100 temperature probes with Sicram module, 4 wire di-
rect Pt100 probes, 2 wire Pt1000 probes complete with TP47 module.
2. pH/mV input, female BNC
3. Battery symbol: displays the battery charge level.
4. Function indicators.
5. Secondary display line.
6. DATA/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 se-
lection. In calibration mode, acquires the nominal buffer value.
7. pH-mV/ESC key: during normal operation switches the display between pH and mV; in the
menu, resets the value set with the arrows. In calibration mode, allows you to exit calibration.
8. key: in the menu, increases the current value. In calibration mode, increases the displayed
nominal buffer value.
9. °C/°F/MENU key: it allows selection of the unit of measurement; when pressed together with
the DATA key, it allows to open the menu.
10. CAL: starts the calibration procedure.
11. /REL-mV key: during normal operation enables the relative measurement (displays the dif-
ference between the current value and the logged value when the key is pressed); press the key
again to return to the normal measurement. It works only if you are displaying the mV.In the
menu, decreases the current value. In calibration mode, decreases the displayed nominal buffer
value.
12. ON-OFF/AUTO-OFF key: turns the instrument on and off; when pressed together with the
°C/°F/MENU key, disables the AutoPowerOff function.
13. MAX (maximum value), MIN (minimum value) and AVG (average value) symbols.
14. Main display line.
15. Line for symbols and comments.

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DESCRIPTION OF THE FUNCTIONS
The keyboard of the pH meter Model HD2305.0 is composed of double-function keys. The function
on the key is the "main function", while the one above the key is the "secondary function".
When the instrument is in standard measurement mode, the main function is active.
Once the Settings Menu has been opened, by pressing simultaneously the DATA+°C/°F keys, 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.
This key has two functions:
ON/OFF: to turn the instrument on press ON, to turn it off press OFF.
The turning on enables all display segments for a few seconds, starts an Auto-test including the de-
tection of the probe connected to the input, and sets the instrument ready for normal measurement.
The following is displayed:
MIN
cm
min s
2
3
mµ
m
k
>>>
AUTO/OFF: the AutoPowerOff function can be disabled by simultaneously pressing this key
and the "°C/°F-MENU" key when turning the instrument on.
During turning on, should no probes be connected, the "NO_PRBE_SER_NUM" message is dis-
played in the line for symbols for a few seconds, while the "ERR" message is shown in the central
part of the display, and 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.
When the probe fitted with SICRAM module is inserted into a functioning instrument, the
"NEW_PROB_DET" (New probe detected) message appears, while the "ERR" message is
shown in the central part of the display, and a sequence of "beeps" is simultaneously issued. As the
data are captured upon turning the instrument on, it is necessary to turn it off and on again.
Caution! Replace the probes when the instrument is off.
ON-OFF and AUTO-OFF key

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The "pH-mV" key has three functions:
pH-mV: pressing this key once switches the display between pH and mV;
ESC: once the MENU has been opened with the DATA+°C/°F keys, the "pH-mV" key will al-
low to cancel the parameters set using the and arrows.
In calibration mode, it allows to exit calibration.
The "DATA" key is used for the following functions:
DATA: during normal measurement, by pressing this key once the maximum (MAX) value of
the measurements captured by the probe connected to the instrument is displayed, updating it
with the acquisition of new samples;
-by pressing this key again the minimum (MIN) value is displayed;
-by pressing this key, a third time the average(AVG) value is displayed.
The acquisition frequency is once a second.
The MAX, MIN and AVG values remain in the memory until the instrument is on, even after
exiting the DATA display function. When the instrument is off, the previously memorized data
are cleared. Upon turning on, the instrument automatically starts memorizing the MAX, MIN
and AVG values.
To reset the previous values and start with a new measurement session:
press DATA until the FUNC_CLRD message appears;
use the and arrows to select YES;
confirm by pressing ENTER.
ENTER: once the MENU has been opened with the DATA+°C/°F keys, the DATA key will
perform the ENTER function and the MENU can be browsed and the displayed parameter con-
firmed. In calibration mode, acquires the nominal buffer value.
Una volta entrati nel MENU, tramite i tasti DATA e °C/°F, il tasto permetterà di incrementare il
valore del parametro selezionato nel MENU. In calibrazione permette di incrementare il valore del
buffer nominale.
Il tasto °C/°F viene utilizzato per le seguenti funzioni:
°C/°F: when the temperature probe is connected, the key changes the unit of measurement from
degrees 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
TDATA/ENTER key
Tasto pH-mV/ESC
key
°C/°F/MENU Key

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change the compensation temperature using the arrows (and ). Confirm using DA-
TA/ENTER. The display stops blinking, and the temperature displayed is used for compensa-
tion. 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.
MENU: to access to the menu press simultaneously DATA+°C/°F: the Probe Type will be
displayed.
use the and arrows (respectively located above the HOLD and REL keys) to modify
the displayed value;
press DATA/ENTER to confirm the modification and go onto the next item;
press CLR/ESC to cancel the modification;
to exit the menu, press the °C/°F key again.
For more info, please see following chapter.
Press this key to start the calibration procedure (vd. par. pH).
The "/ REL-mV" key is used for the following functions:
REL-mV: it displays the difference between the current value and that measured on pressing
the key. The "REL" message is displayed on the left. To return to the normal measurement,
press the key again. It only works with mV, so to enable the REL function select the "mV" unit
of measurement using the "pH-mV" key.
: Once the MENU has been opened with the °C/°F/MENU key, the key will allow to de-
crease the value of the selected parameter. During electrode calibration, it allows to decrease the
nominal buffer value
/ REL-Mv key
CAL key

HD2305.0 - 9 - V1.6
THE PROGRAMMING MENU
To access to the menu press simultaneously the following keys:
The item to be set is:
Probe type: the "PRBE_TYPE_RTD_" message is displayed in the comment line. The main line
in the center of the display shows the type of probe connected to the instrument. The following
probes can be connected to the input:
temperature probes Pt100 complete with SICRAM module
4 wire Pt100 probes through module TP47
2 wire Pt1000 probes through module TP47
The probes fitted with SICRAM module, and Delta Ohm Pt1000 probes, are automatically detected
by the instrument upon turning on: the Probe Type menu item is configured by the instrument and
cannot be modified by the user.
The temperature probes direct 4 wire Pt100, and the Pt1000 probes that are not manufactured by
Delta OHM, when turned on display the message "NO_PRBE_SER_NUM". In this case the probe
type must be entered manually.
Access to the menu by selecting Probe type using the DATA and °C/°F keys at the same time:
-use the and arrows to modify the displayed value;
-press DATA/ENTER to confirm the modification and go onto the next item;
-press pH-mV/ESC to cancel the modification;
-to exit the menu, press the °C/°F key again.

HD2305.0 - 10 - V1.6
PROBES AND MEASUREMENT
The instrument works with the following probes:
electrodes for pH measurement;
electrodes for redox potential ORP measurement (REDOX);
specific ion electrodes.
Caution! The pH measurement is influenced by the temperature measurement.
The temperature is used for the automatic compensation of the Nernst coefficient with the pH
electrode.
The measurement can be performed using probes with the following sensor:
4 wire Pt100;
2 wire Pt1000;
Some probes are fitted with SICRAM module that acts as an interface between the sensor on the
probe and the instrument. There is a microprocessor circuit with a permanent memory inside the
module that enables the instrument to recognize the type of probe connected and to read its calibra-
tion information.
The Delta Ohm Pt1000 probes are automatically detected while the direct 4 wire Pt100 temperature
probe is not automatically detected by the instrument and must be set up in the Probe type menu
item (please see the menu description on chapter 3).
The pH or mV indication is displayed in the main line; the secondary line shows the temperature.
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 instrument is on, it is necessary to turn it
off and on.
The probes fitted with SICRAM module are calibrated in the factory; no calibration is required by
the user.
THE ELECTRODE FOR pH MEASUREMENT
The electrode for pH measurement, generally in glass, generates an electrical signal proportional to
the pH according to Nernst law. Of this signal the following aspects are considered:
Zero point: The pH where the electrode generates a potential of 0 mV. In most electrodes, this
value is found at about 7 pH.
Offset or Asymmetry Potential: represents the potential (in mV) generated by an electrode when
immersed in a buffer solution at 7 pH. Generally oscillates between ± 20 mV.
Slope: response of the electrode expressed in mV per pH units. The theoretical electrode slope at
25°C is 59.16 mV/pH. When the electrode is new the slope is close to the theoretical value.
Sensitivity: it is the electrode's slope expression in relative terms. It is obtained by dividing the
actual value of the slope by the theoretical value, and is expressed as a %. The asymmetry po-
tential and the slope vary in time with the use of the electrode, which necessitates regular cali-
bration.