Fisher Scientific accumet AR50 User manual

USER Manual
AR50

2
Table of Contents
accumet®
RESEARCH
Connectors
Attaching pH and ISE electrodes
Attaching Conductivity Probes
Touch Screen Operation
Choosing a Channel
Button Functions
System Setup
pH Setup
mV Setup
Ion Setup
Conductivity Setup
Standardization
Measurement
Absolute mV Measurement
Relative mV Measurement
4
5
6
8
10
12
14
16
18
20
46
82
90
104
122
124
128
130
131
131
Introduction
Unpacking the Meter
Specifications
Getting Started
Using the Meter
Setup Operations
pH Operations
mV Operations

3
Table of Contents
accumet®
RESEARCH
Direct Reading with Standards
Direct Reading with Blank Offset
Incremental Methods
Known Addition Measurement
Known Subtraction Measurement
Analate Addition Measurement
Analate Subtraction Measurement
Standardization
Measurement
Determining Isopotential Points Experimentally
Data Management
Factory Default Settings
pH Theory
ISE Theory
Conductivity Theory
132
134
137
140
142
146
148
150
154
158
160
161
162
163
164
165
166
167
169
174
178
183
Ion Operations
Conductivity
Operations
Cleaning
Trouble Shooting
Warranty
Compliance
Appendix
Replacement Parts

4
Introduction
accumet®
RESEARCH
Thank you for selecting a Fisher Scientific accumet pH meter. This
manual describes the operation of the accumet AR50 meter. The
state-of-the-art meter that you have purchased is easy to operate and
will guide you through the various functions by displaying easy to
understand prompts. This operating manual should answer any
questions that might arise in operating your meter; however, do not
hesitate to call our Fisher Lab Equipment Technical Support Hotline at
1-800/943-2006 or 412/490-6260, if you need any assistance.
This meter is designed to provide all the information necessary to guide
you through the process of measuring pH, mV, ion concentration, or
conductivity with a series of prompts on the screen.
The accumet Research AR50 provides microprocessor precision in a
compact benchtop design that is easy to use. One touch screen controls
all procedures, letting you:
• Measure pH, absolute mV, relative mV, ion concentration
or conductivity.
• Select one of three sets of standard buffer groups.
• Implement automatic buffer recognition.
• Standardize with up to five standard or custom buffers.
• Customize your display screen and operating parameters.
• Assign operator and sample identification numbers.
• Specify ion selective electrode type.
• Store 250 data points in the meter’s memory or transfer data
to a computer or printer.
• Access extensive online help with just a touch of a button.
It all adds up to rapid, completely automatic, intuitive operation.

5
Unpacking the Meter
accumet®
RESEARCH
The following is a listing of what you should have received with your new
accumet AR50 pH/mV/Ion/Conductivity meter.
Meter with kit includes
meter
power supply
electrode arm support bracket
electrode arm
electrode (13-620-285)
ATC probe (13-620-19)
manual and literature
* Note that this meter does not include a conductivity cell.
Meter only includes
meter
power supply
electrode arm support bracket
manual and literature
If any of these items are missing, please contact the Fisher Products
Group Electrochemistry Operation by dialing 412/490-6267.
Accessory Conductivity Probes and Ion Selective Electrodes are
available and can be ordered by calling Fisher Customer Service
at 800/766-7000.
2-cell Conductivity Probes:
Cell Constant Optimal Conductivity Range Glass Body Epoxy Body
0.1 0.5 to 200 µS/cm 13-620-156 13-620-161
1.0 0.01 to 2 mS/cm 13-620-155 13-620-160
10.0 1 to 200 mS/cm 13-620-157 13-620-162
4-cell Conductivity Probes:
Cell Constant Optimal Conductivity Range Glass Body Epoxy Body
1.0 0.01 to 20 µS/cm 13-620-163 13-620-165
10.0 1 to 200 mS/cm 13-620-164 13-620-166

6
Specifications
accumet®
RESEARCH
640x480 digit LCD
4 1/2” x 6”
3/4”
1/4”
extensive
extensive
yes
context specific touchscreen
250 data pts
yes
store on stable, time, manual
output on stable, time, manual
1 to 9,999 sec
yes
-2.000 to 20.000
0.1/0.01/0.001
± 0.002
yes
yes
5
yes
yes
± 1800.0
0.1
± 0.1
1x10-6 to 9.99x1010
0.1/0.01/0.001
± 0.17n%
5
KA, KS, AA, AS
screen size
measurement display height
temp/etc. display height
menu options
help screens
configurable display
keypad controls
internal diagnostics
programmable data storage
programmable data output
print interval
programmable alarm
range
resolution
relative accuracy
automatic buffer recognition
manual buffer recognition
calibration points
auto lock
FET
range
resolution
accuracy
range
resolution
relative accuracy
calibration points
incremental methods
Display
Memory
pH Mode
mV Mode
Ion Mode

7
Specifications
accumet®
RESEARCH
0.1, 1.0, 10
0 to 3x105µS/cm
30 ohm.cm to 100 megohm.cm
2 to 42 ppt
0.5%
-5.0 to +105.0 °C
0.1 °C
± 0.2 °C
2BNC, 2Pin, 2ATC, 2-pin cond.
RS232, DIN (for FET and 4 cell cond.)
115 V/60 Hz, 230 V/50 Hz
12VDC, 500mA
± 10%
>1012 ohms
5.5” x 7.5” x 3.25”
1.86 lb.
5-45 °C
5-80 % noncondensing
2000m
II
2
cell constants range
conductivity
resistivity
salinity
accuracy
range
resolution
accuracy
inputs/outputs
electrical requirements
output from PSU
line voltage tolerance
input impedance
meter size
meter weight
operating temperature
operation humidity
maximum operating altitude
installation category
Pollution category degree
Conductivity Mode
Temperature Mode
General
Operating Conditions

8
Getting Started
accumet®
RESEARCH
CONNECTORS
POWER RS-232 FET ATC 1 Ref 1 Input 1
AccuFET pH electrode
Automatic Temperature Compensation (ATC)
BNC input connector
Reference pin jack
Conductivity Cells
Review the layout and arrangement of the rear connector panel.
1
2-cell
Conductivity ACT 2 Ref 2
4-cell
Input 2
Power
Computer/Printer
Conductivity

9
Getting Started
accumet®
RESEARCH
CONNECTORS
To connect RS-232, see
Data Management on
page 166.
Connect the electrode arm to the base.
2
Connect the power cable to the
rear connector panel power
jack and to a power source.
3
electrode arm support
POWER

10
Getting Started
accumet®
RESEARCH
pH and ION SPECIFIC ELECTRODES
If both a conventional
electrode and an AccuFET
electrode are connected to
the meter, do not put them
in a solution together
because you will get
inaccurate measurements.
Do not discard the BNC
shorting cap.
This meter allows you to use two types of pH electrodes: the
conventional glass pH electrode and the AccuFET field effect
transistor (FET) pH electrode. If both types of pH electrodes are
connected, the meter will read the AccuFET electrode. This meter
also allows you to use ion specific electrodes.
Carefully remove the protective cover from
the end of the electrode. Before first using
your glass pH electrode, or whenever the
electrode is dry, soak it 2-4 hours in an
electrode storage solution, pH 4 Buffer, or
KCl solution. Before using your ion specific
electrode, consult the manufacturer’s
instructions for electrode preparation.
Remove the shorting cap on BNC connector.
Connect the combination pH electrode by
plugging it into the BNC input connector
(twisting to lock in place).
If a combination electrode isn’t used, connect
the indicating pH electrode into the BNC
input connector. Plug the reference electrode
into the reference pin jack. Also, install the ATC
probe into the ATC jack.
Note: Be sure to connect all probes to the
appropriate channel connectors (for
example: Input 1, Ref 1, and ATC 1).
Option: Connect the optional AccuFET
electrode by plugging it into the FET jack
on the back meter panel. Allow the AccuFET
to warm up five minutes before use.
Connect ion specific electrodes in the same
manner as pH electrodes.
2
1

11
Getting Started
accumet®
RESEARCH
pH and ION SPECIFIC ELECTRODES
Proper electrode care is
fundamental to obtaining
reliable pH measurements.
Improper care of the
electrode may cause the
meter reading to drift,
respond slowly, or
produce erroneous
readings. For this reason,
the electrode should
always be conditioned
and used in accordance
with manufacturer’s
instructions.
Rinse and blot-dry (don't wipe) electrodes
between each measurement. Rinse electrodes
with distilled or deionized water, or a portion of
the next solution to be measured.
Between measurements, store conventional pH
electrodes in electrode storage solution, pH 4
buffer, or KCl solution. Always leave the filling
hole of liquid filled combination electrodes
open. Refill when the level of solution gets
below the manufacturer’s recommended level.
Store ion specific electrodes according to
electrode manufacturer’s recommendations.
3
4

12
Getting Started
accumet®
RESEARCH
CONDUCTIVITY PROBES
This meter also allows you to use two types of conductivity cells:
the 2-cell conductivity cell with dual pin connector and the 4-cell
conductivity cell with DIN connector. The 2-cell conductivity probe
works in channel 1 and the 4-cell conductivity cell works in
channel 2.
Carefully remove the protective cover from
the end of the conductivity cell. Before using
your conductivity cell, soak it for 5 to 10
minutes in distilled or deionized water.
Connect the 2-cell conductivity cell to the
2-cell jack. Install the ATC probe in the
ATC-1 jack.
OR
Connect the 4-cell conductivity cell to the
4-cell jack. The 4-cell accumet conductivity cells
have built in ATC probes. Therefore, there is no
need to install a separate ATC probe.
2
1

13
Getting Started
accumet®
RESEARCH
CONDUCTIVITY PROBES
Rinse and blot-dry (don't wipe) probe
between each measurement. Rinse probe
with distilled or deionized water, or a portion
of the next solution to be measured.
Between measurements, store conductivity
probes dry.
3
4

14
Using the Meter
accumet®
RESEARCH
TOUCH SCREEN OPERATION
Touch anywhere to resume
11:11am
FisherScientific
Standby screen

15
Using the Meter
accumet®
RESEARCH
TOUCH SCREEN OPERATION
The new accumet Research benchtop pH meters operate with a
state-of-the-art touch screen. The touch screen makes this the easiest
meter on the market to operate and care for. When the meter is first
plugged in, the STANDBY screen will appear. Touch anywhere on this
screen to access the functions of the meter.
The buttons on the right side of the screen control all of the functions of
the meter. A light touch on the screen is all that you need to access the
various functions. Once you touch a button you will get an audible tone;
the screen will not change until you lift your finger. This
design prevents rapid uncontrolled scrolling through the various function
screens. Function buttons and options change from screen to screen.
Easy to understand prompts guide you through the operation of the
meter in the selected mode. If you are ever in doubt about what to do,
just touch help on the bottom right corner of the screen for detailed
information about that screen.
The touch screen is made of a durable polyester material that is
chemically resistant. Maintenance is simple with this meter. To clean
the screen you just need to wipe it with a damp cloth and dry it
with a clean dry towel. For additional information, see cleaning
and troubleshooting sections of the manual (pages 160-161).

16
Using the Meter
accumet®
RESEARCH
CHOOSING A CHANNEL
Select your desired measurement channel
stdby
help
FisherScientific
accumet AR50
dual
1
2
September 17, 1997 11:11 am
Select from the options to the right
pH
mV
Ion
setup
channel
Cond
September 17, 1997 11:11am
FisherScientific
accumet AR50
Measure
stdby
help
9.295
pH
print
STND Last std: Sep 17 @ 10:10 am
0.010
uS/cm
BUFFERS Last std: Sep 17 @ 10:17 am
ATC
slope
mV
26.2°C
000.0%
0000.0
ID#
auto buffer
auto read
00000
ON
ON
September 17, 1997 11:11 am
1
2
channel 1
channel 2
ATC
Ref
Co
26.2°C
25°C
0.00%/°C
ID#
Cell K
00000
1.00/cm
Main screen Channel screen
Dual screen

17
Using the Meter
accumet®
RESEARCH
CHOOSING A CHANNEL
If you are in any measure
mode, touch mode until
you access the main
screen.
The accumet Research AR50 is a Multi-channel pH meter. With this
meter you can switch from channel 1 to channel 2. You can also view
both channels at the same time by accessing the dual channel mode.
If you set the meter to view both channels, you cannot change the
parameters without choosing the screen that you want to modify. The
setup parameters for each screen are setup independently of one
another.
Choosing a Channel
Touch anywhere on the Standby screen.
OR
Touch channel on the main screen.
THEN
Touch 1, 2or dual to access the channel that you want to view.
To access System Setup from the Standby screen
Touch anywhere on the Standby screen.
Touch 1or 2on the channel screen to access either channel.
Touch setup.
Touch system on the Setup screen.
1
2
1
2
3
4

18
accumet®
RESEARCH
BUTTON FUNCTIONS
The touch screen of your accumet Research pH meter has “buttons” along the
right side of the screen that are common to many of the screens. The following
indicates the function of these common buttons.
channel
stdby
mode
enter
exit
save
help
close
more
back
Using the Meter
This button allows you to access the channel screen to choose what
channel you want to view. This button appears only on multichannel
meters such as the accumet AR25 and AR50. This button also allows
you to move from the main mode screen to the channel screen to access
the standby mode.
The mode button allows you to switch between the various operations
of the meter. These operations, depending upon which meter you have,
include four measuring modes (pH, mV, ion, conductivity) as well as a
setup mode.
The enter button allows you to accept any changes that you have made
on setup screens or accept values that you have input with keypads.
When touched, enter will save the changes and return you to the previous
screen.
The save button allows you to save multiple changes you have made on
one screen as a group. It functions like the enter button does for individual
changes.
The help button allows you to access helpful information on any screen.
When you touch the help button, information about the current screen
appears. This information will include step-by-step instructions for operating
the meter from the current screen and possible applications information for
that screen.
The close key appears on the bottom of all help screens and allows you
to exit the help screen and return to the previous screen.
The more button appears on the help screens and allows you to
advance to the next help screen for additional information.
The back button appears on the help screens and allows you to
move back to a previous help screen.
The exit button allows you to leave the screen you are currently viewing
and return to the previous screen without making any changes.
This is the standby button and it allows you to access the standby
mode. When in standby, the meter will not take measurements. It is in a
state of rest. When you touch stdby the meter will return to the standby
screen which says “Fisher Scientific” and displays the time.

19
Using the Meter
accumet®
RESEARCH
BUTTON FUNCTIONS
meas
std
setup
print
edit
clear
BS
delete
prev
next
This button accesses the standardization screen from the various
measure modes and initiates standardization of the meter once the
standardization screen is accessed.
This button is the measure button and directs the meter to measure your
sample when in the Auto Read function of the pH or Ion modes.
This button will access the setup screens for the measuring mode that
you are currently using. It can also be used to access the system setup
screen that allows you to set parameters that are not related to measure-
ments such as the time and the date.
The print button will send information to the output device that you
have connected to your accumet meter. The output device can be a
printer, data logger or a computer. In addition to this, touching the print
button will also send data to the data storage center of the meter if a
sample ID# has been assigned to your sample.
The arrow keys on the screen move the cursor up and down in order
to highlight parameters that you would like to review or edit.
The edit button appears on the setup screens. After you have highlighted
a parameter that you would like to change, the edit button allows you to
access the available options for that parameter.
The BS button is a backspace button. It appears on keypad screens and
it allows you to back up and delete a character entered in error.
The delete button appears on the “View Stored Data” screens. This
button allows you to erase the data from the memory of the meter.
The prev button appears on the Data Screens when the data stored in
the meter’s memory has been accessed. It allows you to scroll through
data points sorted and stored prior to the current data point displayed.
The next button appears on the Data Screens when the data
stored in the meter’s memory has been accessed. It allows you
to scroll through data points sorted and stored after the current data
point displayed.
The clear button allows you to remove a setup parameter or standard
buffer value from the meter’s memory that may have been entered at a
previous time or by a previous user that is no longer of value to you.
Touching the clear button erases the value so you may enter a new one.
It can also erase a parameter that you may have entered erroneously.