Omega Products PHB-220 Installation Manual

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User ’s Guide

PHB-215 pH Meter

PHB-220 pH/Conductivity Meter

PHB-225 pH/Ion Meter

PHB-250 pH/Ion/Conductivity Meter

PHB-215

pH m

eter

Servicing North America:

USA: One Omega Drive, Box 4047

ISO 9001 Certified Stamford, CT 06907-0047

Tel: [phone] FAX: [phone]
e-mail: [e-mail]

Canada: 976 Bergar

Laval (Quebec) H7L 5A1
Tel: [phone] FAX: [phone]
e-mail: [e-mail]

For immediate technical or application assistance:

USA and Canada: Sales Service: 1-800-826-6342 / 1-800-TC-OMEGA

SM

Customer Service: 1-800-622-2378 / 1-800-622-BEST

SM

Engineering Service: 1-800-872-9436 / 1-800-USA-WHEN

SM

TELEX: 996404 EASYLINK: 62968934 CABLE: OMEGA

Mexico and
Latin America:

Tel: (95) 800-TC-OMEGA

SM

FAX: [phone]

En Espan÷ol: [phone] e-mail: [e-mail]

Servicing Europe:

Benelux: Postbus 8034, 1180 LA Amstelveen, The Netherlands

Tel: [phone] FAX: [phone]
Toll Free in Benelux: 06 0993344
e-mail: [e-mail]

Czech Republic: ul. Rude armady 1868, 733 01 Kavrine-Hranice,

Czech Republic
Tel: [phone] FAX: [phone]
e-mail: [e-mail]

France: 9, rue Denis Papin, 78190 Trappes

Tel: [phone] FAX: [phone]
Toll Free in France: 0800-4-06342
e-mail: [e-mail]

Germany/Austria: Daimlerstrasse 26, D-75392 Deckenpfronn, Germany

Tel: [phone] FAX: [phone]
Toll Free in Germany: 0130 11 21 66
e-mail: [e-mail]

United Kingdom: 25 Swannington Road, P.O. Box 7, Omega Drive,

ISO 9002 Certified Broughton Astley, Leicestershire, Irlam, Manchester,

LE9 6TU, England M44 5EX, England
Tel: [phone] Tel: [phone]
FAX: [phone] FAX: [phone]

Toll Free in England: 0800-488-488

e-mail: [e-mail]

omega.comomega.com

OMEGAnetSMOn-Line Service Internet e-mail

http://www.omega.com [e-mail]

It is the policy of OMEGA to comply with all worldwide safety and EMC/EMI regulations that
apply. OMEGA is constantly pursuing certification of its products to the European New Approach
Directives. OMEGA will add the CE mark to every appropriate device upon certification.

The information contained in this document is believed to be correct but OMEGA Engineering, Inc. accepts
no liability for any errors it contains, and reserves the right to alter specifications without notice.
WARNING: These products are not designed for use in, and should not be used for, patient connected applications.

OMEGA

TM

®

Quick Start Guide for pH Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . Page ii

Introduction

Menu Keys,Softkeys and Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Electrode Connectors and Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

LCD Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Function Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Electrodes

Preparing pH and Ion Selective Electrodes. . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Connecting Electrodes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Using and Storing Electrodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

pH Electrodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Solid-State FET Electrodes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Ion Selective Electrodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Meter Setup

Meter Setup Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

pH Mode

pH Mode Standardization Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Cal Reminder Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Select Custom Buffer Set. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

pH Mode Options Menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Standardizing and Measuring pH. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Clearing Buffers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

mV Mode

mV Mode Standardization Menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

mV Mode Options Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Clearing Relative mV Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Quick Start Guide for Ion Measurement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Ion Mode

Ion Mode Standardization Menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Standardizing and Measuring Ion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Measuring Ion using a Known Addition type (incremental ion) method. . . 17

Quick Start Guide for Conductivity/Resistivity/Salinity/TDS Measurement. . . . 18

Conductivity/Resistivity/Salinity/TDS Modes

Conductivity/Resistivity/Salinity/TDS Standardize Menu . . . . . . . . . . . . . . . . 19

Conductivity/Resistivity/Salinity/TDS Options Menu . . . . . . . . . . . . . . . . . . . . 20

Data logging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Meter Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

pH Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Ion Selective Electrode Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Determining Isopotential Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

RS-232 Serial Interface Meter Command Set. . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Table of Contents

i

1.Connect power cable to meter connector on
the rear panel marked “power”and to AC power
source.

2.Connect the glass pH/ATC electrode to the
channel A BNC connector marked “ch.A”and to
the channel A temperature connector marked
“temp A”.

3.Verify the meter is in pH mode on channel A.Use
the Mode key and Channel key to set the meter
to the correct mode and channel if necessary.
(See Function keys).

4.Standardize the electrode by immersing the
electrode in a buffer,pressing Standardize, press­ing 1) Auto-enter a buffer and following the
prompts.Repeat this step to enter each buffer.
The meter will check the electrode and buffers,
and give an error message if there is a problem.

Press Standardize to enter or clear buffers,select
buffers, set resolution, or set other parameters for
the current mode and channel.

5.The display shows the current measurement,and
indicates a stable reading with the indicator.
Press Cal Data to review and graph the elec­trode calibration data.

ii

Quick Start Guide for pH Measurement

A 7.000

pH

25.0°C

No buffers.

Mode

Channel A: pH mode

Standardize Menu

1) Auto-enter a buffer

2) Manual buffer entry

3) Clear buffers

4) Options menu

5) Cal reminder menu

6) Select buffer set

channel
indicator

units
indicator

Channel

Standardize

A 7.000

pH

25.0°C

4.008 pH

7.000

entered
buffers

“power”

“ch. A”

“temp A”

s

s

stability
indicator

s

c

h

. A

re

f. A

c

h

T

e

m

c

p

o

. A

n

d

. C

T

e

m

p

. B

R

S

2

3

2

C

p

o

w

e

r

c

h

. A

c

h

re

f. A

T

c

e

o

m

n

p

d

. A

. C

T

e

m

p

. B

R

S

2

3

2

C

p

o

w

e

r

This Omega meter is a powerful,versatile and accurate instrument. It features
easy menu-based operation with easy to understand prompts and
electrode/standard error checking.

These meters feature many advanced options,such as programmable stability
criteria, programmable standardization reading delay times, multi-channel oper­ation,fast reading update rates of twice per second for all channels,program­mable alarms, programmable data logging of 500 data points and a superb RS­232 serial interface for controlling the meter and obtaining data.

Omega meters use flash programmable ROM for the operating code.The meter
operating code can easily be upgraded as new features are made available.

Direct Menu Keys, Softkeys and Display

The meter uses six Direct Menu keys to access the menus and operations (such
as selecting pH mode,standardizing,checking electrode calibration data,
selecting the electrode channel).

There are four Softkeys that provide additional operations; these Softkeys
change their function as needed and each Softkey has an icon to indicate its
current function.

The display is a backlit quarter-VGA screen capable of displaying all four elec­trode channels (of a PHB-250) simultaneously. The backlight will turn off after a 45
minute period of non-use; pressing any key will automatically turn the backlight
on again.

A S

7.001

pH

25.0¡C

4.008 pH

7.000

6/30/1998 02:28 PM

Denver Instrument

S

1

Introduction

Softkeys

Direct Menu

Keys

Direct Menu

Keys

Numeric

Keypad

PHB-215

pH m

eter

Electrode Connectors and Inputs
BNC ("ch.A" or "ch.B") connectors: pH,Ion

Selective Electrodes and ORP (redox) elec­trodes attach to the meter through a BNC
("round twist-on") connector to channel A or
channel B (PHB-225 and PHB-250 only).

Temperature ("temp A" or "temp B") connec­tors: use to connect the 2.5mm mini-phone

plug from the temperature sensor (built into
the pH electrode with the Omega standard
pH/ATC electrode) for Automatic Temperature
Compensation (ATC).

Reference ("ref.A" or "ref.B") connectors: use
for attaching a reference electrode tip-pin
plug when a separate reference electrode is
used.

Conductivity DIN (“ch.C conductivity”)
connector: use to connect a 4-band conduc-

tivity/ATC cell.These 4-band cells offer
improved linearity and stability over older 2­band conductivity cells. (PHB-220 and PHB-250
only).

FET DIN ("ch.F FET") connector: use to connect
the Denver Solid-State Field Effect Transistor
(FET) pH/ATC electrode. These non-glass pH
electrodes offer certain advantages over con­ventional glass pH electrodes.

Serial port ("RS232") DB-9 connector: use to
connect a serial printer or Personal Computer.
This bi-directional interface outputs data and
receives meter commands.

Power (“power”) connector: use to connect a

5.5mm OD x 2.1 ID coaxial connector with
12VDC at 500mA (center pin negative).

2

Introduction

Connectors for PHB-250

ch. A

ref. A

ref

temp

A

ch. F

FET

RS232C

power

D

Note: Not all of the following will display at the
same time.

A

. Result: current measurement.

B

.Units: displays the units for the current measure-

ment.Examples: pH, mV, mg/L F-,µS/cm or
W-cm.

C

.Softkey icons: show the current function

assigned to each softkey.

D

.Calibration due reminder: the icon means

a calibration is now due.

E

. Date and time: displayable in different formats.

F

.Da talogging: the icon indicates datalog-

ging is active.

G

.Buffers/Standards: in single channel mode,all

entered buffers or standards are displayed.A
“!”symbol beside a buffer indicates that buffer
is out of the entered calibration valid time (See
Calibration reminder,page 9).

H

.Temperature: displays the measured tempera-

ture when an electrode with ATC or separate
temperature probe is attached.Shows “M”
when a manually entered temperature is being
used.

I

.Alar m: “*”indicator means data is outside the

set alarm limits.

J

Channel: indicates which electrode channel
(input) is being displayed.Channel A and
Channel B (PHB-225 only) are BNC inputs.
Channel F is the FET electrode input.

K

.Stability: the indicates the electrode is sta-

ble to the selected criteria.

L

.Multiple Channel: display can show two

(PHB- 215),three (PHB-220 and PHB-225) or four
(PHB-250) electrode measurements with tem­perature simultaneously.

M

.Out-of-range or non-valid reading: dashes indi-

cate a measurement is not available.This usual­ly means the reading is out of range,or can
mean in ion mode that no standards have
been entered,or strict calibration has been set
and the calibration expired.

3

Display

*

A 7.000

pH

25.0°C

4.008 pH

7.000

9.999

6/30/1998 02:28 PM

A B

J
I
H
G

E

C

Single channel display

K

F

A 6.998

pH

24.6°C

B 1.02

mg/L

23.4°C F-

30-6-1998 14:28:05

Dual channel display

L

A pH

23.8

°

C

1998.6.30 14:28:30

M

s

s

s

CAL!

Log

S

A

.Mode: Selects the mode: pH,mV

(PHB-215),Ion (PHB-225 and PHB-250),
Conductivity - Resistivity-NaCl Salinity­Practical Salinity-TDS (PHB-220 and
PHB-250) to use for the currently selected
channel (electrode input).

B

.Standardize: Enters buffers or standards

for the currently selected channel and
mode.Use to enter pH buffers,relative mV
offset,ion standards or conductivity /resis­tivity standards.

Also used to change other settings which
affect the measurement.

C

.Cal Data: Displays and graphs buffers or

standards with time and date stamp and
electrode calibration data for the select­ed channel and mode.

D

.Channel: Selects the channel(s) (elec-

trode inputs) to display.The PHB-215 can
display one or two channels simultane­ously (Channels A and F).The PHB-225
can display one,two or three channels
simultaneously (Channels A,B and F). The
PHB-220 can display up to three channels
(Channels A,C and F).The PHB-250 can
display up to four channels (Channels A,
B,C and F).

E

.Setup: The Setup menu is used to set vari-

ous general meter settings,such as date
and time,display contrast,keypress beep
and serial port.

F

.Da ta Log: Displays the datalogging menu

used to set datalogging and view the
stored Data Log (see Datalogging).

G

.Clear: Exits from the current menu and

returns to the previous menu,cancels the
current operation or clears a number
entry.

H

.Enter/Pr int: Accepts numeric values,menu

selections or pending operations.In the
main measure screen,acts as a Print key,
sending all current measurements to a
printer/ computer through the serial port
and stores the measurements in the Data
Log.

I

.Softkeys: These four keys access different

operations at different times.Most menus
offer a “Help” softkey and the “Measure”
softkey, w hich allows a direct return to the
main measuring screen,exiting all menus
immediately. The “Up Arrow”and “Down
Arrow”softkeys offer one way to select a
menu item.The “Left Arrow”key is a back­space,active during number entry.

J

.Numer ic Keys: Pressing a number key

selects a numbered item in a menu.The
number keys also allow entering values for
buffers, standards, and various meter set­tings.

4

Function Keys

Help

Measure

Scroll up

Scroll down

Backspace

Graph

Exponent number entry

Incremental ion method

Measure lock

Measure unlock

Softkeys

E

–

+

5

Function Keys

A

B

C

D

E

F

G

H

I

J

Channels

The Channel key is used to turn on or off each
available channel.In single-channel operation,
additional information for the selected channel is
provided,including a display list of all entered
buffers or standards. In multi-channel operation,
the Mode,Standardize and Cal Data menus ask
for the channel before accessing the menu.

The PHB-215 offers single or dual channel opera­tion using channel A ( pH and ORP electrodes)
and channel F (Solid-state FET pH electrode).The
PHB-225 offers up to three-channel simultaneous
operation of channel A and channel B (pH,ORP
and Ion Selective Electrodes) and channel F
(Solid-state FET pH electrode).

The PHB-220 has Channel A (pH and ORP elec­trodes),Channel C (Conductivity cells) and
Channel F (solid-state FET pH electrode).The
PHB-250 provides up to four channel measure­ment with Channel A and Channel B (pH and
ORP and Ion Selective electrodes),Channel C
(Conductivity cells) and Channel F (solid-state
FET pH electrode).

Configure Display

1) Turn channel A on/off: ON

2) Turn channel B on/off: ON

3) Turn channel F on/off: OFF

4) Turn channel C on/off: ON

5) Measurement screen

PHB-250 Select Channel

screen

Channel

?

Mode

Standardize

Data Log

Cal Data

Channel

Enter/Print

Setup

Clear

The meter allows you to use a variety of glass mem­brane (“glass”) pH/ATC electrodes,ion selective elec­trodes,Conductivity/ATC cells,the Omega Field Effect
Transistor (FET) Solid-State pH/ATC electrode,tempera­ture (ATC) probes, combination electrodes using a BNC
connector,or separate electrode pairs with BNC con­nector and reference pin.

Preparing Electrodes and Conductivity Cells

Remove the wetting cap or storage cap from the elec­trode.Before first using your pH electrode or whenever
the electrode is dry,soak it several hours in an elec­trode filling or storage solution (3 Molar KCl solution) or
in a buffer for pH electrodes. Condition ISE’s in the rec­ommended solutions. Rinse Conductivity cells with
deionized water before use.

Connecting Electrodes
pH, ORP or ISE electrodes (with BNC connector):

Connect the electrode to the BNC input,either chan­nel A or channel B (PHB-225 and PHB-250 only),located
at the rear of the meter.Push in and rotate the elec­trode’s BNC connector until it locks in place.Connect
the ATC connector to the temp.A or temp.B connec­tor. To disconnect, twist the BNC connector in the
opposite direction and pull.

Electrode Pair Using a Reference Electrode (with
Reference Pin Plug):

Connect the indicating electrode to the BNC input.
Connect the reference electrode to the Reference
input.Push the electrode’s tip pin plug into the input to
connect and pull out to disconnect.

Conductivity Cells (with DIN connector):

Align and push in the DIN connector fully to the chan­nel C input (PHB-220 and PHB-250 only).Pull carefully to
disconnect.

6

Electrodes

To measure Use channel (connector)

pH A (BNC)*

or

B (BNC)*

mV (ORP) A (BNC)*

or

B (BNC)*

ion (ISE) A (BNC)*

or

B (BNC)*
Conductivity C (DIN)
Resistivity C (DIN)
Salinity C (DIN)
TDS C (DIN)
pH (FET) F (mini-DIN)

*Separate reference electrodes can be used with “Ref A”or
“Ref B”connectors

BNC
Connector

Channel C
Conductivity Input

ATC
Connector

Channel F
FET pH Input

ch. A

ref. A

ref

temp

A

ch. F

FET

Using and Storing Electrodes

pH Electrodes

• Provide moderate stirring for faster electrode
response.

• Leave the fill hole open during all use.

• Rinse the electrode between each measurement
with a portion of the next sample or buffer to be
measured,or with deionized or distilled water.

• Keep glass electrodes wet when not being used
by placing some electrode filling solution in the
wetting cap and storing with the wetting cap on.

• Keeping glass electrodes “wet”will improve their
performance.Store electrodes in electrode filling
solution or storage solution (3M KCl).

Solid-State FET Electrode

• All models allow use of both standard glass
pH/ATC and Solid-State FET (Field Effect Transistor)
pH/ATC electrodes.The meter can store a cali­bration for both types of electrodes.Plug the FET
electrode into the channel F mini-DIN input.

• Allow the FET about 1 minute to stabilize when
first connected.The FET electrode can be stored
dry or in electrode storage solution.Provide mod­erate stirring.

Ion Selective Electrodes

• Add proper amount of Ionic Strength Adjuster
(ISA) to all standards and samples,usually 1 mL
ISA to 50 mL standard or sample.

• Provide moderate stirring for faster electrode
response.

• Rinse the electrode(s) between each measure­ment with a portion of the next sample or stan­dard to be measured,or with deionized or dis­tilled water.

• Follow the instruction sheets for the individual
electrode.Store as recommended.

Conductivity Cells

• When changing samples or standards,immerse
the cell into the new solution,then lift and allow
solution to drain out.Repeat two more times.

• Gently tap cell to dislodge air bubbles.

7

Electrodes

Store with wetting
cap and Fill
Solution (3M KCl)

Provide
moderate
stirring

Store FET and
Conductivity
Cells dry