EUTECH INSTRUMENTS CYBERSCAN PH 10002500 PHION METER User manual

Instruction Manual
pH 1000/ pH 2500
Bench pH/Ion Meter
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Rev. 5 07/03

Instruction Manual pH 1000/ 2500

Instruction Manual pH 1000/ 2500
Preface
Thank you for choosing the pH 1000/ 2500 bench meter series.
This manual serves to explain the use of the pH 1000/ 2500 Bench meter. The manual functions in two
ways, firstly as a step-by-step operational guide to help you familiarize with the meter’s features and
functions. Secondly, it serves as a handy reference guide.
This instruction manual is written to cover as many anticipated applications and uses of the pH 1000/ 2500
bench meter as possible. If there are doubts in the use of the meter, please do not hesitate to contact the
nearest Authorized Distributors.
Eutech Instruments/ Oakton Instruments cannot accept any responsibility for damage or malfunction to the
meter caused by improper use of the instrument.
The information presented in this manual is subject to change without notice as improvements are made,
and does not represent a commitment on the part of Eutech Instruments Pte Ltd/ Oakton Instruments.
Note: Eutech Instruments Pte Ltd/ Oakton Instruments reserves the right to make improvements in
design, construction, and appearance of our products without notice.
Copyright © 1998 All rights reserved.
Eutech Instruments Pte Ltd
Oakton Instruments
Rev. 5 07/03

Instruction Manual pH 1000/ 2500
TABLE OF CONTENTS
1INTRODUCTION 1
2METER INFORMATION 1
2.1 Meter Parts 1
2.2 Customized LCD 1
2.3 Slide Out Card 1
2.4 Rear Instrument Panel 1
2.5 AC/DC-Adapter 2
2.6 Electrode 2
3KEYPAD FUNCTIONS 3
3.1 Primary & Secondary Functions of Keypad 3
4STARTING UP THE METER 6
4.1 Connecting the Sensor Electrode 6
4.2 Connecting the Temperature Probe 6
4.3 Connecting the AC/DC Adapter 6
4.4 Connecting the Chart Recorder 6
4.5 Connecting RS232C Cable 6
5TURNING THE METER ON AND OFF 7
6CALIBRATION 8
6.1 pH Calibration (With ATC) 8
6.1.1 1 Point pH Calibration 8
6.1.2 Option 1 - Standard Buffers 8
6.1.3 Option 2 - Non-Standard Buffers 9
6.2 Multi-Point pH Calibration (Up to 5 Points) 9
6.3 Special Topic: CAL EDIT (for Custom/Non-Standard Buffers) 10
6.4 pH Calibration (without ATC) 10
6.5 Relative mV Calibration 11
6.6 Ion Calibration (for pH 2500 only) 12
6.7 Temperature Calibration 13
7MEASUREMENT: READY, CONTINUOUS AND HOLD 14
7.1 Measurement in the READY Mode 14
7.2 Measuring in the Continuous Mode 14
7.3 HOLD Function 14
7.3.1 Holding and Releasing a Measured Value 14
7.4 Measuring pH 15
7.5 Measuring mV 15
7.6 Measuring Relative mV 16
7.7 Measuring Ion (for pH 2500 only) 16
8SETUP FUNCTIONS AND KEYS 17
9PROGRAM 1: LAST CALIBRATION TIME, DATE AND TEMPERATURE 18
10 PROGRAM 2: MEMORY RESET AND AUTO-OFF FUNCTION 19
11 PROGRAM 3: SET CURRENT TIME AND DATE 19
12 PROGRAM 4: COMMUNICATION SETUP 20
12.1 Switching pH Resolution 22
12.2 Setting the READY Indicator 22
12.3 Setting the Audible Beep 22
12.4 Viewing pH Electrode Offset 22
12.5 Viewing pH Electrode Slope 22
12.6 Viewing Ion Electrode Slope (for pH2500 only) 22
12.7 Setting the High and Low Setpoint Alarm (pH/mV/Relative mV) 23
12.8 Setting & Activating the Timer 23
12.9 Setting the Timer 24
12.10 Activating the Timer 24
12.11 Memory Input Functions and Options 25
12.12 Print Functions and Options 26
12.12.1 Print Function Options 26
13 TROUBLESHOOTING AND ERROR MESSAGES 27

Instruction Manual pH 1000/ 2500
14 ELECTRODE CARE 28
14.1 Electrode Activation 28
14.2 Electrode Maintenance 28
14.3 Storing pH/ORP electrodes 28
15 METER SPECIFICATIONS 29
16 ACCESSORIES 30
17 WARRANTY 32
18 RETURN OF ITEMS 32

Instruction Manual pH 1000/ 2500
1
1 INTRODUCTION
Thank you for selecting pH1000/ 2500 bench meter. This step-by-step instruction manual gives you a
detailed description on the use and operation of features on the meter. There are 2 models: pH1000
(pH/ mV/ Relative mV/ Temperature/ RS232C) and pH2500 (pH/ Ion/ mV/ Relative mV/ Temperature /
RS232C). These meters are designed to be user-friendly while providing unprecedented levels of
accuracy, repeatability and reliability.
The pH 1000/ 2500 bench meter is an advanced microprocessor-based (ASIC-Application Specific
Integrated Circuit) ideal for routine measurement that best meets discerning user’s individual needs.
This feature-rich meter has splash-proof keypad, simultaneous pH/ mV/ Ion and temperature display
on a large angled custom LCD. Besides, the meter allows user customization via its SETUP feature,
making the unit more powerful and user-friendly to cater to your individual needs. This instruction
manual is illustrated with useful hints and diagrams that show which specific key-presses to access for
each function.
2 METER INFORMATION
The pH 1000/ 2500 bench meter is packaged in a corrugated box which is made of environment-
friendly materials and can be re-cycled.
2.1 Meter Parts
The instrument is designed to give an aesthetic look as well as ergonomic functionality. A large
custom dual LCD is provided at an angle for optimum viewing. A splash proof keypad with audible
tactile response gives you a good feel of the instrument. A slide-out instruction card offers a handy
reference in case of doubts. Listed below are the major parts of the meter.
2.2 Customized LCD
The pH 1000/ 2500 bench meter is characterized by large dual custom LCD (Liquid Crystal Display).
The display has also mode annunciators for pH, temperature, relative mV and mV readings. The
secondary (lower) display shows the temperature readings simultaneously with the primary (upper)
display of measured mode. Special annunciators such as graphical symbols, error messages,
measurement units and modes of operation are arranged around the primary and secondary displays
to give a comprehensive display. The integration of graphics and error messages into the LCD
provides you a higher level of user-friendliness and easy readability.
2.3 Slide Out Card
A plastic slide out card is provided at the bottom of the bench meter. The function of this card is to
provide a quick guide to the functions of the individual keys as well as to provide a useful trouble
shooting reference.
2.4 Rear Instrument Panel
The pH 1000/ 2500 bench meter provides a set of connectors for the various accessories commonly
used. In addition to all the connectors, pH 1000/ 2500 bench meter has an additional RS232C port to
allow for data transmission between the meter and a printer or computer, Furthermore; it can be
remotely controlled using a software from Eutech Instruments. Listed as follows are various
connections available.

Instruction Manual pH 1000/ 2500
2
Connector Function
ATC For phono jack connection from the temperature probe for Automatic Temperature
Compensation. The probe should be a thermister type probe.
INPUT For connecting sensors with a BNC connector to the meter. The meter accepts any pH,
ORP or ISE electrode with a BNC connector. Always make sure that the connector is
clean and dry.
REF For connection to the pin tip type reference electrode normally used with half cell (mono)
type pH or ISE electrodes.
REC For connection to the strip chart recorder.
GND For connection to the ground earth jack (standard pin tip connectors).
RS232C For connection to the RS232C serial port.
DC For connection to the AC power source to the power jack (DC).
Rear View of the Meter
2.5 AC/DC-Adapter
AC/DC adapters convert the power mains voltage 120/220 VAC to low DC voltage for the pH 1000/
2500 bench meter operation. Two basic models of adapters are available depending upon power
supply specification of each country. See accessories section.
2.6 Electrode
Electrode is one of the most important parts of the meter. The electrode glass membrane is fragile and
must be handled with care. A protective rubber cap containing a suitable storage solution to protect
the glass membrane and to maintain activation of the glass membrane covers the pH electrode
provided with the meter (when ordered). A special protective guide for use during measurements is
enclosed to offer added protection against damage to the pH electrode glass bulb during operation.
Maintenance of electrode is necessary from time to time. Please refer to Section 14 on Electrode
Care.

Instruction Manual pH 1000/ 2500
3
3 KEYPAD FUNCTIONS
The pH 1000/ 2500 bench meter is equipped with large tactile response keypad for ease of use. All
keys have primary function with some keys having secondary functions.
3.1 Primary & Secondary Functions of Keypad
ON/OFF
Primary Function Turns meter on or off.
Secondary Function None
Numeric Value None
SHIFT
Primary Function Press to access the secondary functions of the meter.
Secondary Function None
Numeric Value None
YES
Primary Function Enter numeric values, confirm calibration points, or confirm and scroll program options
or values selected.
Secondary Function None
Numeric Value None
NO
Primary Function Use to cancel incorrectly selected numeric value or selection made.
Secondary Function None
Numeric Value None

Instruction Manual pH 1000/ 2500
4
CAL/MEAS
Primary Function Press to toggle between measurement and calibration modes of the meter - pH,
Temperature, mV, Relative mV and Ion. Also use as exit from SETUP mode,
secondary functions and to abort operation while in calibration mode.
Secondary Function None
Numeric Value None
1 / MODE
Primary Function Select one of four measurement modes: pH/mV/Relative mV/Ion.
Secondary Function None
Numeric Value 1
2 / HOLD
Primary Function Freeze the displayed value. Allow you to print the held reading or store it into memory.
Secondary Function None
Numeric Value 2
3 / SETUP / REL MV BASE
Primary Function Enter SETUP mode of the meter for customization of meter functions as well as view
some diagnostic functions.
Secondary Function Display the Relative mV base value while in Relative mV mode and Ion Electrode
Slope while in the Ion mode.
Numeric Value 3
4 / ∆/ RESLN
Primary Function Select next higher pH buffer values in the pH calibration mode. Also used to scroll
through SETUP mode options.
Secondary Function Toggle the pH resolution between 0.01 pH and 0.1 pH.
Numeric Value 4
5 /∇/ SLOPE
Primary Function Select the next lower pH buffer value option in pH calibration mode. Also used to
scroll through some SETUP mode options.
Secondary Function Display the percentage slope of the pH electrode when in the pH mode. While in Ion
mode, it displays slope of ion electrode in mV/decade.
Numeric Value 5
6 / SET TEMP / OFFSET
Primary Function Press to calibrate ATC temperature probe or to set manual temperature.
Secondary Function Displays the offset of pH electrode. This is useful as a diagnostic function to
determine the quality of the probe that is connected to the meter.
Numeric Value 6

Instruction Manual pH 1000/ 2500
5
7 / CAL EDIT / BEEP
Primary Function Press to edit pH buffer value while you are in pH calibration mode.
Secondary Function Turns on or off ‘beep’ sound whenever a key-press is depressed.
Numeric Value 7
8 / ALARM / READY
Primary Function Enter the high and/or low alarm values.
Secondary Function Turns on or off the READY function.
Numeric Value 8
9 / ACTIVATE / SET TIMER
Primary Function Press to start timer countdown.
Secondary Function Sets the time interval.
Numeric Value 9
. / MI / OPT
Primary Function Stores the displayed value into memory.
Secondary Function Activate different Memory Input Options, these include:
Data Log on Ready
Data Log on Time Interval
Set Time Interval for Data Log
Numeric Value . (decimal point)
0 / MR / OPT
Primary Function Recalls stored values from the memory in the Last-In-First-Out (LIFO) sequence.
Secondary Function Activate different Memory Recall options. There are two options:
Print all memory data
Clear memory
Numeric Value 0
+/- / PRINT / OPT
Primary Function Output the displayed data through the serial/RS232C port. Can be activated in the
measurement, HOLD functions and memory recall functions.
Secondary Function Sets the different print options. There are three options:
Print on ready
Print on time interval
Set print time interval
Numeric Value +/-

Instruction Manual pH 1000/ 2500
6
4 STARTING UP THE METER
4.1 Connecting the Sensor Electrode
Slide the sensor electrode connector of the electrode over the INPUT BNC socket. Then push the
connector into the socket and turn the connector clockwise to lock into position. Do not use excessive
force. This applies to combination pH/ORP/ISE electrodes. For half-cell sensors where a reference
electrode is used, connect the sensor connector to socket marked (REF). Always ensure that the
connectors are dry when connection is done.
4.2 Connecting the Temperature Probe
The temperature probe uses a phono jack to connect with the socket marked ATC on the meter. Insert
the jack directly into the socket until it is firmly seated.
4.3 Connecting the AC/DC Adapter
Ensure that the power to the AC/DC adapter is switched off. Slide the AC/DC adapter jack into the
socket marked DC of the meter until it is firmly seated. For AC/DC adapter always ensure that the
power mains voltage matches that of the adapter used. AC/DC adapters used should have the
following specifications or settings. Output:- Voltage: 9 V DC Current: 500 mA.
NOTE: Ensure that the input power mains voltage (120/220 V)
matches your adapter requirements.
4.4 Connecting the Chart Recorder
The meter provides a recorder output of +/- 2000 mV for transmission of readings either to a chart
recorder or to a data acquisition device (Analog/Digital Cards). When the chart recorder is in
operation, continuous absolute mV readings will be charted. Note that readings are independent of the
operating mode and is uncompensated and set to a one to one (1:1) ratio.
Where the charting is made in reference to ground potential, a cable is connected from the GND port
of the meter to the chart recorder. Plug the phono connector to the meter at the designated port
(marked REC). The tip (inner) connection should be wired to the high side of the recorder and the
sleeve (outer) side should be wired to the low side of the recorder.
4.5 Connecting RS232C Cable
Noting the orientation of RS232C connector, insert the 9-pin male connector from your device (a
printer or computer) into the RS232C port (marked RS232) of the meter. Fasten the RS232C
connector using the two screws at the side of the male RS232C connector. Do not over-tighten.

Instruction Manual pH 1000/ 2500
7
5 TURNING THE METER ON AND OFF
Once the AC/DC adapter is connected and powered on,
the meter beeps and the full LCD lights up for a few
seconds to display all segments as a self-diagnostic
test of the LCD. Then the meter will display the current
time.
To access the meter functions, press ON/OFF key. The
meter beeps and performs a diagnostic test before
going into the pH measurement [MEAS] mode. To turn
the meter off, press ON/OFF key within the operation
mode. The meter performs a self-diagnostic LCD test
before displaying the current time.
IMPORTANT :
Remember to remove the protective cap from
the electrode tip prior to measurement.
Replace it in place after use or store electrode
in some storage solution to avoid possible
dehydration of glass bulb which may result in
slow response.
In any case if the electrode is not in use for
long period, condition the electrode by
soaking into tap water for 1-2 hours before use.
Make sure to wash electrodes/probes
before/after each sample measurements to
prevent any carry-over of samples.

Instruction Manual pH 1000/ 2500
8
HINT: For best results, perform
at least a 2-Point Calibration
using buffers that bracket the
expected range of
measurement. If a 1 Point
Calibration is to be used, it is
highly recommended that
measurement be performed
only at points close to the
calibration value.
The primary display of the LCD shows
the measured pH value; the
secondary display shows the value of
the standard solution (pH 1.68, 4.01,
7.00, 10.01, 12.45). To select other
buffer values, use arrow keys.
6 CALIBRATION
6.1 pH Calibration (With ATC)
The pH 1000/ 2500 bench meter is capable of multi-point
calibration up to 5 points for enhanced full range accuracy
using standard pH buffer options at pH 1.68, 4.01, 7.00,
10.01 and 12.45. In addition, these meters allow added
flexibility for you to calibrate using other non-standard
calibration buffers (via the CAL EDIT feature).
6.1.1 1 Point pH Calibration
1. Make sure the meter is ON and if necessary, press the MODE
key to select pH mode. The pH indicator appears in the upper
right hand corner of the display.
2. Rinse the electrode thoroughly with deionised water or a rinse
solution. If using the ATC function with a separate temperature
probe, rinse the temperature probe as well. DO NOT wipe both
probes dry as it will cause a build-up of static and create
instability in calibration and measurement.
3. Select the pH buffer and pour some into a clean container.
Immerse both probes into the selected buffer and press CAL
key, a [CAL] annunciator appears. The primary display shows
the measured pH reading while the secondary display indicates
the pH buffer value for calibration.
4. Select the correct buffer value on the meter. If the buffer used
is a standard value, use OPTION 1. Otherwise use OPTION 2
to calibrate the meter to the required value.
6.1.2 Option 1 - Standard Buffers
Select desired pH buffer standard using Sor Tkey to scroll
to the correct buffer value as indicated in the secondary
display to that of the prepared buffer solution.
If the selected buffer is not within the accepted window (see
below) from the measured pH value, the electrode and
buffer icons flash and [ERR] annunciator appears next to the
secondary display.
Window of Accepted Values:
pH 1.68 ±1.00 pH 10.01 ±1.00
pH 4.01 ±1.00 pH 12.45 ±1.00
pH 7.00 ±1.50
1. When reading stabilizes, a [READY] annunciator is displayed
on left hand side of the LCD. Note the READY annunciator will
be displayed after you have activated this function prior to
measurement or calibration. For details refer to Section 7.1.
2. Press YES to confirm calibration or NO to cancel and re-enter.
Upon confirmation, the CON indicator flashes at the top right
hand side of the LCD to indicate that the instrument is now
calibrated to the selected buffer. The secondary display
automatically scrolls to the next pH buffer option.
3. You have performed one-point calibration successfully using
standard buffer option after pressing YES key. To resume to
measurement mode, press CAL/MEAS key while you are in
the calibration mode.
Note: The LCD will display
the actual pH value of
the buffer at the point of
calibration. For example,
a pH 10.01 (@ 25 oC)
buffer when calibrated at
20oC will actually have a
value of pH 10.06.
Therefore, the meter will
display this value of 10.06.

Instruction Manual pH 1000/ 2500
9
6.1.3 Option 2 - Non-Standard Buffers
1. Press CAL EDIT key after entering into pH calibration mode.
The buffer icon blinks at the bottom left hand corner of the
LCD. Select the buffer value by entering the value directly via
the keypad numeric keys. For example, 9.18. The value
entered is displayed in the secondary display. Please ensure
the correct pH buffer sample is available during calibration.
2. When reading stabilizes, a [READY] annunciator is displayed
on left hand side of the LCD. Note this READY annunciator will
be displayed after you have activated this function prior to
measurement or calibration. For details refer to Section 7.1.
3. Press YES to confirm calibration or NO to cancel and re-enter.
Upon confirmation, the CON indicator flashes at the top right
hand side of the LCD to indicate that the instrument is now
calibrated to the selected buffer. The secondary display
automatically scrolls to the next pH buffer option.
4. You have performed one-point calibration using non-standard
buffer option successfully after pressing YES key. To resume
to measurement mode, press CAL/MEAS key while in the
calibration mode. The primary display shows the calibrated pH
buffer value (in this case, pH 9.18) and the secondary display
shows the measured temperature value.
6.2 Multi-Point pH Calibration (Up to 5 Points)
1. Follow steps 1 to 4 of “1 Point Calibration”.
2. If your 1 Point Calibration began with the default buffer value of
pH 7.00 (@ 25 oC), then the meter automatically scrolls to the
next value, pH 4.01. The next value automatically shown is
1.68 after which the value scrolls round to 12.45 and then
10.01 and back again to 7.00.
3. To select the second buffer you wish to calibrate at, use Sor
Tkey to scroll through the buffer options.
4. Follow steps (2) to (4) of the 1 Point Calibration procedure until
the entire buffer values that you wish to calibrate are complete.
Do not press CAL/MEAS key until all calibration is complete.
5. Press CAL/MEAS key when all calibrations are complete to
return to the measurement mode. Display now shows MEAS.
Important: OR Indicator
The ERR indicator flashes if the buffer value is
not within +/-1 pH of the measured buffer
value. This indicator also flashes if the buffer
value is different from that shown on the
secondary display.

Instruction Manual pH 1000/ 2500
10
6.3 Special Topic: CAL EDIT (for Custom/Non-
Standard Buffers)
The pH 1000/ 2500 bench meter allows non-standard or
custom buffer solutions to be used for calibration. This is
especially useful in applications where the use of special or
non-standard pH buffer solution is required. To use, follow
the steps as described.
1. When in the CAL (pH) mode, press CAL EDIT key. Refer to
section 6.1.3 for further details.
2. The buffer icon at the bottom of the LCD blinks.
3. Enter the desired pH value using the numeric keys.
4. Confirm calibration by pressing YES or NO to re-enter the
value.
5. To enter another non-standard value, repeat steps 1 to 4
again.
NOTE :
As the buffer value entered in the CAL EDIT
mode is non-standard, the meter will not retain
that buffer as an option in future calibrations.
You have to re-enter the value of the buffer.
The division of the calibration ranges to a pH
range within +/1 pH of the standard buffer
options ensures that only one point can be
calibrated in any one of the five ranges.
.
6.4 pH Calibration (without ATC)
Manual Temperature Compensation (MTC) is done by
manually setting the temperature to that of the buffer prior to
calibration. The procedure to set the temperature is outlined
in the section on Temperature Calibration.
Set the desired temperature value in the meter using
software calibration procedure outlined in the Temperature
Calibration. Calibrate for pH using the steps for pH
calibration (ATC) using steps (1) - (5) of Multi-point pH
Calibration.
IMPORTANT: For manual compensation, the temperature
probe must be disconnected. The ATC annunciator is not
displayed on the right hand side of LCD when in calibration
and measurement modes.

Instruction Manual pH 1000/ 2500
11
6.5 Relative mV Calibration
Relative millivolt calibration is normally used for Redox
sensors in which you set a base value. For the selection
and preparation of appropriate calibration solutions,
consult the instruction manuals for the Redox/ORP
electrodes.
1. Make the appropriate electrode connections and switch on the
meter.
2. Select [Rel] [mV] mode by pressing MODE key repeatedly until
the Relative mV mode is accessed.
3. Press CAL/MEAS key to activate calibration mode. The [CAL]
annunciator displays on top of the LCD. The LCD displays the
absolute mV reading.
4. Select the Base Offset value using the numeric keys. The
resulting value displayed in the measurement mode, is
[Absolute mV displayed] - [Base Offset]. Once this value is
entered, the Redox/ORP probe is calibrated to the selected
standard.
5. Press YES to confirm selected value or NO to cancel and re-
enter the value. If calibration has been successfully performed,
the meter is now calibrated for relative mV measurements.
6. Press CAL/MEAS key to return to the measurement mode. The
primary display shows the measured relative mV readings.
Hint 1: To set the Relative mV offset to 0.0 using the
present calibration solution, proceed to step (5) without
entering any value.
Hint 2: For Redox/ORP calibration, set the Relative mV
offset using the following equation:
[ Relative mV Offset ] = [Displayed Value] - [Value of
Standard/Desired Value]
Hint 3: To recall the selected Base Offset, press SHIFT and
followed by Relative mV Base key on the keypad.

Instruction Manual pH 1000/ 2500
12
6.6 Ion Calibration (for pH 2500 only)
Ion calibration is used for ion selective electrodes (ISE). For
the selection and preparation of appropriate calibration
solutions, consult the instruction manuals for the list of ISE
probes and calibration standards available.
1. Make the appropriate electrode connections and switch on the
meter.
2. Select mode by pressing MODE key repeatedly until the Ion
mode is accessed, as indicated in the LCD. Dip electrode(s) in
first standard.
3. Press CAL/MEAS key to activate calibration mode. The ‘CAL‘
indicator displays on the LCD. Top display shows measured
mV value from electrode and bottom display shows 1 indicating
first standard.
4. Once the ‘READY’ indicator displays, press CAL EDIT key to
enter the concentration value of the standard. Use numeric
keys to enter the value 0 to 9999. When entering concentration
value, if decimal point is pressed, then rest of the digits (total 4
digits) must be entered e.g. 10 or 10.00. The available
calibration options include 0.1; 1.0 or 1; 10.0 or 10; 100.0 or
100 and 1000. Refer to below notes for details.
5. Press YES to confirm the selected value or NO to cancel and
re-enter the value.
6. For the next calibration value, wash electrode with deionised
water and dip it into second standard and repeat step 4.
Proceed to next calibration points until you have finished. Press
CAL/MEAS key to switch to measurement mode if calibration is
done using less than 5 standards.
7. At the end of fifth standard ion calibration, the meter switches
to [MEAS] mode automatically once these values are entered.
The ISE probe is calibrated to the selected standard solutions.
NOTE: Minimum number of calibration for Ion is 2
points, maximum is 5 points. At least 2 standards
(preferably one decade apart in concentration
value) must be used to complete the calibration.
If less than 2 standards are used then calibration is
ignored. Refer to Troubleshooting
IMPORTANT :
Make sure to wash electrode between samples to
prevent cross-contamination. It is advisable to
read samples in the order of low concentration to
high concentration.

Instruction Manual pH 1000/ 2500
13
6.7 Temperature Calibration
In this calibration procedure, the ATC probe is attached to the
meter and the ATC annunciator displays on the right hand
side of the LCD.
1. Dip the temperature probe into a solution of known temperature,
such as a temperature bath for a few minutes until the
temperature probe stabilizes. Determine the temperature of the
sample to be measured using an accurate thermometer.
2. To perform temperature calibration, press MODE key to select
the temperature mode.
3. Press SET TEMP to set the desired temperature to match that
measured value. The CAL annunciator lights up.
4. Select the temperature value using the numeric keys.
5. Press YES to confirm the selected temperature. The CON
annunciator flashes for one second and disappears. The meter
reverts to the pH measurement mode. The temperature is now
set to the temperature selected. Note: Temperature can only be
set between -9.9oC to 110.0oC.
IMPORTANT :
Always conform to the temperature limits of the
sensor probe (e.g. epoxy pH probes with a built in
temperature sensor should not be used or
calibrated at temperatures above 80 oC.) If
unsure, check with specifications of the probe.

Instruction Manual pH 1000/ 2500
14
7 MEASUREMENT: READY, CONTINUOUS
AND HOLD
7.1 Measurement in the READY Mode
The READY annunciator appears the readings are stable at
the top left corner of the LCD. The reading is held as long as
the variation of readings is within a range. (For pH, tolerance
is +/- 0.02 pH. For mV, tolerance is +/- 0.3 mV < 400 mV and
+/- 1.2 mV > 400 mV).
1. Rinse the pH electrode using de-ionized or distilled water prior to
use. This will remove impurities that have adhered on the
electrode body.
2. Switch to the MEAS mode for measurement. The MEAS mode is
activated whenever the meter is switched on. If you are in the
calibration mode, press CAL/MEAS key to revert to the
measurement mode.
3. Dip the electrode into the sample ensuring that the glass bulb of
the electrode is completely immersed into the sample. Swirl
electrode gently in the sample. When reading stabilizes, the
READY annunciator displays.
NOTE:
If the READY indicator is turned off, the readings are
instantaneous readings. Allow readings to stabilize
before reading for highest accuracy.
7.2 Measuring in the Continuous Mode
As the READY function provides stable readings, the
continuous mode provides instantaneous readings for faster
operation. Continuous mode readings, however, may not be
as stable. To turn off READY, see page 22. Follow steps (1)
to (3) of READY mode measurements.
7.3 HOLD Function
This feature allows you to hold the value of the measurement
reading until it is more convenient to note the reading. This
mode can be activated at any time when you are in the MEAS
mode. You can store the held value into memory if HOLD is
active.
7.3.1 Holding and Releasing a Measured Value
In the measurement mode, press HOLD key to hold a
displayed value. When HOLD mode is activated, the HOLD
mode annunciator displays.
To release a held value, press HOLD key again. The HOLD
mode annunciator disappears from the LCD and the meter
reverts to its measurement mode.

Instruction Manual pH 1000/ 2500
15
7.4 Measuring pH
The meter automatically goes to the pH measurement mode
when you power it on.
1. If you are not in the pH measuring mode, press MODE key until
the mode annunciator at the bottom of the LCD shows that the
meter is in the pH mode.
2. To measure in READY mode, follow steps (1) to (3) of the steps
in “Measuring in the READY Mode”.
3. The primary display shows the pH reading and the secondary
field shows the temperature.
7.5 Measuring mV
1. If you are not in the mV measuring mode, press MODE key until
the mode annunciator at the bottom of the LCD shows that the
meter is in the mV mode.
2. To measure in READY mode, follow steps (2) to (3) of the steps
in “Measuring in the READY Mode”.
3. The primary display shows the mV reading and the secondary
field will show the temperature. The resolution will be 0.1 mV
within the +/-399.9 mV range and +/-1 mV beyond. Beyond the
operation range of the meter, it will show “Ur” and “Or” in the
primary display to denote under range and over range
respectively.
NOTE:
Electrode can be attached to an electrode
holder for a more stable operation.
Remember to remove the rubber cap from the
electrode tip prior to measurement.