Omega Products PHH-925 Installation Manual

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User ’s Guide

PHH-925 and PHH-950

pH Meters

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]

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.

Quick Start. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page ii

Introduction

Electrode Connector Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Batteries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

LCD Display. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Function Keys. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Electrodes

Preparing pH and Ion Selective Electrodes . . . . . . . . . . . . . . . . 4

Preparing Conductivity Cells. . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Connecting Electrodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Using and Storing Electrodes. . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

pH Electrodes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Solid-State FET Electrodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

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

Conductivity Cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Meter Operation

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

Standardizing and Measuring pH

pH StandardizatIon Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Standardizing and Measuring pH . . . . . . . . . . . . . . . . . . . . . . . 10

Clearing Buffers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Standardizing and Measuring mV

Relative mV Standardization Menu . . . . . . . . . . . . . . . . . . . . . 12

Clearing Relative mV Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Standardizing and Measuring Ion

Ion Standardization Menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Standardizing and Measuring Ion. . . . . . . . . . . . . . . . . . . . . . . 14

Clearing Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Standardizing and Measuring Conductivity

Conductivity Standardization Menu. . . . . . . . . . . . . . . . . . . . . 15

Standardizing and Measuring Conductivity,

Salinity,Resistivity or TDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Clearing Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Temperature Compensation. . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Determining Temperature Coefficients. . . . . . . . . . . . . . . . . . . 18

Datalogging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Appendix A: Power Station and Docking Station . . . . . . . . . . . . . 20

Appendix B: Error Conditions and Troubleshooting . . . . . . . . . . . 22

Appendix C: Basic pH Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Appendix D: Ion Selective Electrode Theory . . . . . . . . . . . . . . . . 26

Appendix E: Conductivity Theory . . . . . . . . . . . . . . . . . . . . . . . . . 27

Appendix F: Determining Isopotential Point . . . . . . . . . . . . . . . . . 28

Appendix G: Meter Specifications . . . . . . . . . . . . . . . . . . . . . . . . 30

Maintenance and Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

i

The following quickly steps you through meter operation.For
detailed instructions on each step,refer to the page(s) indicated.

Step Description Page

1. Install Batteries Install four AA alkaline batteries 1
into the rear battery compartment.

2. Connect Install electrode in the appropriate 5

Electrode connector input on top of the meter.

3. Turn Meter On Press On/Off. 3

4. Select Channel Make sure that the channel selected, 3
A (Twist-Lock input) or B (BNCinput),
matches the electrode connection.
Press channel and select. Note: If no
electrode is connected to channel A
Twist-Lock input,only channel B is
allowed.

5.Set Mode For the channel A Twist-Lock input, 3
the meter automatically recognizes
the electrode connected,and selects
the appropriate modes. For channel B
BNC input,any allowed mode can be
selected.Press mode and select.

6. Standardize Immerse the electrode into a buffer or 9 (pH)
standard and stir.Press std (standard- 13 (ion)
ize) and follow the prompts.Repeat 15 (Conductivity)
this step to enter buffers or standards.

5. Print Press Print to send the measurement 19
to the internal datalog and out to a
printer/computer ( if using the Docking
Station).

Warning: Use of this product in a manner not specified by the

manufacturer may impair any safety protection provid­ed by the equipment.

!

This manual explains the operation of
PHH-925 and PHH-950 meters for obtain­ing pH,mV, ion and conductivity (PHH-

950) measurements.Before beginning,we
recommend that you become familiar
with the various features of your meter:

Electrode Connector Inputs

Twist-Lock: Used for attaching pH/ATC,

FET pH/ATC,conductivity/ATC cells or
ATC (temperature) electrodes with the
waterproof Twist-Lock connector.
BNC: Used for attaching pH,ORP,or ISE
electrodes with BNC connector.
Reference: Used for attaching a sepa­rate reference probe.

Batteries

The meter requires four AA alkaline bat­teries (unless used with the optional
Power or Docking Station).To install bat­teries, slide the compartment cover open
by pressing in and down where indicat­ed.Position the batteries according to
the directional markings and insert.Slide
the cover closed.

Note: Nickel-cadmium rechargeable

batteries can be used,but their
operating life is half that of alkaline
cells, and they cannot be
recharged in the meter.

LCD Display

BNC

Reference Twist-Lock

1

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

Temperature: The meter displays
the measured temperature when
an electrode with ATC or separate
temperature probe is attached.
Shows M when a manually entered
temperature is being used.

Result: Current measurement.
BAT: Indicates that the meter has

10% of battery life remaining
(approximately 4 hours),or AC
indicates that the meter is con­nected to the Docking or Power
Station.

Channel: Indicates result is from A
(Twist-Lock input) or B (BNC input).

Manual Temperature: M indicates
that measurement is using a manu­ally entered temperature in place
of the automatic temperature.(See
page 13).

Date: The meter displays the cur­rent date,either in mm/dd/yy or
dd/mm/yy format.

Buffers/Standards: Shows individual
buffers or standards that have
been entered.

Stability symbols: S indicates the
reading is stable,U indicates an
unstable reading.

Mode: Indicates the meter is in pH,
mV, ion, rel mV,conductivity,resistivi­ty,salinity or TDS mode.

Time: Displays the current time in
either 12 hour AM/PM or 24 hour
format.

Function Keys

A

M 25.0°C

BAT

7.000

A M pH

4.00

7.00

10.00

1/24/97 11:52 AM

S

G

A

I

F

D

J

C

B

E

H

B

C

D

E

F

G

H

I

J

Single Channel Display

21.3°C

7.000

A pH

1.00

B M mg/L F­1/24/97 11:53 AM

Dual Channel Display

S

S

mode: Selects the mode (pH,mV, ISE

temperature,conductivity,resistivi­ty,salinity,or TDS) to use for the
currently selected channel (elec­trode input).

std: Initiates standardization process

for the currently selected mode to
enter pH buffers, ion standards or
conductivity standards.

channel: Selects the channel(s) (electrode

inputs) to display.

slope: Displays buffers or standards and

calibration data in slope display.
Press data to see the time and
date for each calibration point.

print: Outputs the current result or cali-

bration data to the Docking
Station RS232 interface and the
internal datalog.

setup: Calls the setup menu (see Setup).
Up/Down Scrolls when viewing stored data

Arrows: and sets the display contrast.
data: Enters the datalogging menu

(see Datalogging).

enter: Accepts numeric values,menu

selections or pending operations.

on/off: Turns the meter on and off.
clear: Clears an incorrect number entry

or cancels the current operation.

Numeric Enters number s for menu selec-
Keypad: tion, standard entry and other

operations.

+ Enters a negative value.

•: Enters a decimal point.
10X: Enters the exponential part of a

number.

1

4

7

2

5

8

3

6

9

0

+

.

10

x

mode

std channel

slope

print setup

data

enter

on/off

clear

3

Electrodes

The meter allows you to use a variety of
glass membrane (“glass”) pH/ATC elec­trodes,ion selective electrodes,the Field
Effect Transistor (FET) Solid-State pH/ATC
electrode (PHH-925 only),temperature
(ATC) probes,Conductivity/ATC cells (AP50
only),combination electrodes using a BNC
connector,or separate electrode pairs with
BNC connector and reference pin.The
glass pH,FET pH and conductivity cells with
Twist-Lock connector are automatically
detected and identified by the meter.

Preparing pH and Ion Selective Electrodes

Remove the protective end cover or the
soaker bottle 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 (4
Molar KCl solution) or in a buffer for pH
electrodes.Store and condition ISE’s in the
recommended solutions.

Preparing Conductivity Cells

Remove the protective end cover from the
cell.Rinse the cell with deionized or de­mineralized water.

To measure Use channel (connector)

pH A (Twist-Lock)

or

B (BNC)
ORP (mV) B (BNC)
FET pH A (Twist-Lock)
ISE B (BNC & Reference)
Conductivity A (Twist-Lock)
pH & ISE A (Twist-Lock pH)

and

B (BNC ISE)
pH & Conductivity A (Twist-Lock Cond.)

and

B (BNC pH)

Connecting Electrodes

Note: If you install an electrode with a

Twist-Lock connector,the meter
automatically senses it and selects
the appropriate mode and stan­dardize menus for that type of

electrode.

Glass pH/ATC, FET pH/ATC electrode, con­ductivity/ATC cell or ATC Probe (with
Twist-Lock connector):

Connect the electrode to the Twist-Lock
input located at the top of the meter.Line
up the white arrow and line on the elec­trode’s Twist-Lock connector and push
until it locks in place.To disconnect,twist
the connector ring in the arrow direction
and pull apart.

pH, ORP or ISE electrode (with BNC con­nector):

Connect the electrode to the BNC input
located at the top of the meter.Push in
and rotate the electrode’s BNC connec­tor until it locks in place.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.

BNC
Input

Twist Lock
Input

5

BNC
Input

Reference
Input

Using and Storing Electrodes

pH Electrodes

Provide moderate stirring for faster
electrode response.

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 moistening the cotton in
their end covers with electrode filling
solution and storing them with end
covers on,or by placing in their stor­age vials.

Keeping glass electrodes “wet”will
improve their performance.In the la b,
store electrodes in electrode filling solu­tion or storage solution (4M KCl).For
electrodes used in field applications,
occasionally leave them in solutions for
several hours.

Solid-State FET Electrode

The model PHH-925 allows 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 Twist-lock
input. Allow the FET about 2 minutes to
warm up and stabilize when first con­nected.The FET electrode can be
stored dry or in electrode storage solu­tion.If the FET electrode remains con­nected to the meter (and batteries are
in the meter),further warm up is not
necessary.

Ion Selective Electrodes

Add proper amount of Ionic Strength
Adjuster (ISA) to all standards and
samples.

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.

In the lab, follow the instruction sheets
for the individual electrode.Store as
recommended.

Conductivity Cells

Rinse the cell between each measure­ment with a portion of the next sample
or standard to be measured.

Immerse the cell fully into the standard
or sample to be measured,lift the cell
to allow the solution inside the cell to
drain,and immerse the cell again.
Repeat three times.

Stir briefly and tap the cell against the
container bottom to dislodge air
bubbles.

Clean any deposits from the cell body
by rinsing with deionized water and
store dry.

7

Setup Menu

Press setup to access the menu options.

1. Check batter y - Indicates the bat­tery power remaining.

2. Set sleep mode - Enter the time in

minutes before the meter auto­matically turns itself off (“sleeps”) if
no keystrokes have been pressed.
Enter a value of 0 to keep the
meter on continuously. The maxi­mum time allowed is 999 minutes.

3. Set sample ID# - Select a starting
value for the sample ID number.
Sample measurements will then
be identified by sequential sample
ID numbers. Each time the print
key is pressed the sample number
will be incremented.

4. Set time and date - Enter time and

format,and date and format.

5. Signal averag ing - Set the meter
to very slow (10 readings),slow
(8),medium (6),fast (4) and very
fast (2).The meter places each
new reading into a moving win­dow,from which it calculates the
average (displayed) and standard
deviation (for stability determina­tion).

6. Manual tempera ture - Enter a tem­perature to be used in the
absence of an ATC probe or with
manual temperature override.

7. Set contrast - Adjust the display
contrast.

8. Pr inter baud rate - Select the baud
rate for the RS232

input/output.

Pressing a number key causes that menu
selection to be chosen or that operation
to be executed.

Setup Menu

1 - Check battery
2 - Set sleep mode
3 - Set sample ID#
4 - Set time and date
5 - Signal averaging
6 - Manual temperature
7 - Set contrast
8 - Printer baud rate