YOKOGAWA PH71 User manual

User’s
Manual
IM 12B03D01-01E
Model PH71
Personal pH Meter
IM 12B03D01-01E
3rd Edition

1
Preface
IM 12B03D01-01E
3rd Edition: Aug. 2009 (YK)
All Rights Reserved, Copyright © 2004, Yokogawa Electric Corporation
Preface
Thank you for purchasing the Model PH71 Personal pH Meter. Please read this manual
thoroughly before using the meter.
The following symbol marks are used for safety precautions in this manual.
WARNING
: Indicates that serious injury may result, if the user fails to
follow instructions.
CAUTION : Indicates that minor injury to personnel, or damage to the
equipment, may result if the user fails to follow instructions.
WARNING
Do NOT use this instrument where there is a possibility of electrical shock.
Do NOT touch any part of the electrode immediately after using in very hot liquids —
otherwise, you may get burned.
CAUTION
Do not apply physical shock or excessive force to the glass sensor, or it may break.
If the meter will not be used for an extended period of time, be sure to remove the
batteries. Otherwise battery leakage may occur, causing damage to or malfunction of the
meter.
The contents of this manual are subject to change without prior notice.
Yokogawa Electric Corporation assumes no liability for damage, defects, or loss of the
product caused by any of the following:
Misuse by the user;
Inappropriate or out-of-specifications use of the product;
Use in an unsuitable environment;
Repair or modification of this or related products by persons other than Yokogawa-
authorized engineers.

IM 12B03D01-01E
2
Preface
Liquid Crystal Display (LCD) Characters
On the LCD alphanumeric characters are displayed as follows.
9
8
7
6
5
4
3
2
1
0
Z
Y
X
W
V
U
T
S
R
Q
P
O
N
M
L
K
J
I
H
G
F
E
D
C
B
A
Alphabet DisplayAlphabet Display DisplayNumerals
F00.EPS
All display segments
Note Regarding Panels Shown in this Manual:
Panels shown in this manual should be regarded as examples. Actual panel format may
vary depending on parameter settings and on type of connected sensor.
Flashing Displays
Flashing messages, numbers and digits on the display are indicated in gray in this
manual.
Flashing state: Lit state:

IM 12B03D01-01E 3
Preface
Warranty and Service
Yokogawa products and parts are guaranteed to be free from defects in workmanship and
materials under normal use and service for a period of (typically) 12 months from the
date of shipment from the manufacturer.
Individual sales units may offer different warranty periods, so the original purchase order
should be consulted for the conditions of sale. Damage caused by normal wear and tear,
inadequate maintenance, corrosion, or due to chemical processes, is excluded from this
warranty coverage.
In the event of a warranty claim, any items that are considered to be defective should be
sent (freight paid) for repair or replacement (at Yokogawa discretion) to the service
department of the relevant sales unit. The following information must be included in a
letter accompanying the returned items:
Model code and serial number
Copy of original purchase order showing the date
Length of time used, and the measuring environment
Fault symptoms, and circumstances of failure
Statement whether service under warranty or out-of-warranty service is requested
Complete shipping and billing instructions for return of goods, plus the name and
phone number of a contact person who can be reached for further information
Goods that have been in contact with process fluids must be decontaminated / disinfected
before shipment, and a statement to this effect should be included. Safety data sheets for
all process components that the goods have exposed to should also be included.

IM 12B03D01-01E
4
Contents
CONTENTS
Preface...................................................................................................................... 1-1
1. Outline ................................................................................................................. 1-1
1.1 Features ......................................................................................................................... 1-1
1.2 Specifications ................................................................................................................. 1-2
1.3 When You Receive the PH71 Meter Package .............................................................. 1-3
1.4 PH71 Meter Kit .............................................................................................................. 1-4
1.5 PH71 Meter — Part Names and Functions .................................................................. 1-5
1.6 Sensors — Types, Part Names and Functions............................................................. 1-6
1.7 Options (Available Separately) ...................................................................................... 1-7
1.8 Spare Parts .................................................................................................................... 1-8
2. Preparation.......................................................................................................... 2-1
2.1 Installing the Batteries ................................................................................................... 2-1
2.2 Connecting the Sensor Cable ....................................................................................... 2-2
2.3 Setting the Date and Time ............................................................................................ 2-3
2.4 Wetting Cap ................................................................................................................... 2-4
2.5 Manual Temperature Setting ......................................................................................... 2-4
2.6 pH Calibration ................................................................................................................ 2-5
3. Measurement ...................................................................................................... 3-1
3.1 Precautions .................................................................................................................... 3-1
3.2 Measurement Procedures ............................................................................................. 3-2
3.3 Measurement Display Panel.......................................................................................... 3-3
3.4 Saving a Measured Value ............................................................................................. 3-3
4. Calibration ........................................................................................................... 4-1
4.1 Automatic Calibration ..................................................................................................... 4-3
4.2 Manual Calibration ......................................................................................................... 4-6
5. Keypad and Display Functions ......................................................................... 5-1
5.1 Keypad Functions .......................................................................................................... 5-2
5.2 Display Items ................................................................................................................. 5-4
5.3 Function Mode ............................................................................................................... 5-5
6. Maintenance ........................................................................................................ 6-1
6.1 For Optimum Meter Performance .................................................................................. 6-1
6.2 pH Electrode Cleaning................................................................................................... 6-2
6.3 Sensor Replacement ..................................................................................................... 6-3
6.4 Rehydrating the Glass Electrode................................................................................... 6-3
6.5 Replenishing the Electrode with Filling Solution (KCl solution) .................................... 6-4
6.6 Cleaning and Drying Connectors .................................................................................. 6-5
6.7 Storage and O-ring/Gasket Replacement ..................................................................... 6-6
7. Troubleshooting ................................................................................................. 7-1
7.1 Causes of Abnormal Readings and Errors ................................................................... 7-1
7.2 Error Messages, Possible Causes, and Corrective Actions ......................................... 7-2
7.3 Causes of Abnormal Measured Values......................................................................... 7-5
7.4 Other Conditions ............................................................................................................ 7-6
8. Technical Information......................................................................................... 8-1
8.1 Measurement Principle of pH Meter (Glass Electrode Method) ................................... 8-1
8.2 Relationship between EMF of Glass Membrane and pH Value ................................... 8-2
8.3 Temperature Compensation .......................................................................................... 8-4
8.4 The Asymmetry Potential .............................................................................................. 8-5
8.5 The Alkaline Error .......................................................................................................... 8-6
8.6 The Acid Error ............................................................................................................... 8-7
8.7 Calibration Calculation ................................................................................................... 8-8
8.8 Wetted Part Materials of Sensors ................................................................................. 8-9

IM 12B03D01-01E 5
Contents
8.9 References..................................................................................................................... 8-9
Appendix ..................................................................................................................... 1
MSDS (Material Safety Data Sheet) ............................................................... MADS-1
Revision Record .......................................................................................................... i

IM 12B03D01-01E
6
Contents

IM 12B03D01-01E 1-1
1.Outline
1. Outline
The Model PH71 Personal pH Meter is a highly accurate, portable pH meter for
laboratory and field application. With its self-diagnostic function, the PH71 provides
precise measurement of pH. Measurement results can be stored and stored data can be
checked on the meter display any time. The PH71 meter is of waterproof construction so
that it can safely be used outdoors on a rainy day, and can also withstand being
accidentally dropped into water.
1.1 Features
Water resistant case
When this meter is used with its dedicated sensor, it meets the requirements of class IP67
according to “Degree of Protection Provided by Enclosure” in IEC 60529.
Simple calibration
Automatic calibration based on preprogrammed data of standard solutions or manual
calibration can be done through simple key operations.
Calendar and clock function
Internal clock functions allow “one-touch checking” of measurement date and time.
Data storage function
Up to 300 measured pH values along with their respective solution temperatures, dates
and times, can be stored and stored data can be checked on the display any time.
Auto power off function
The meter will turn off power automatically if not operated during a preset time period.
The auto power off time can be user configurable in the range of 1 to 120 minutes in
increments of 1 minute. The auto power off function can be disabled, where the meter
should be used with care to conserve the batteries.
Alarm clock function
The meter can issue an alarm signal at a specified time. Even when meter power is
turned off, the internal clock can issue an alarm signal.
Self-diagnostic function
A relevant error message will appear based on the self-diagnostic function.
Large, clear LCD
A measured pH value, solution temperature, date and time are clearly viewed on the
display.
Compact, lightweight, and handy
The meter fits comfortably your hand and also stands firm on the table.

IM 12B03D01-01E
1-2
1.Outline
1.2 Specifications
Measuring range: pH: 0 to 14 pH*1
Temperature: 0 to 1008C*2
Resolution: pH: 0.01 pH
Temperature: 0.18C
Repeatability (without sensor): pH: 60.01 pH 61 digit
Accuracy (Temperature): 60.78C (0 to 708C)
618C (above 708C)
Temperature compensation (glass electrode emf — temperature characteristics):
Automatic compensation (or manual compensation*1)
Solution temperature: 0 to 808C (or 0 to 1008C*3) (0 to 508C when a KCl replenish-
free type sensor and its sensor cable are immersed in water)
Solution conductivity: 50 mS/cm or more
Ambient temperature: 0 to 508C
Construction: Protection class IP67 (IEC 60529)
Power source: 2x AA batteries (LR6)
Auto power off function (time configurable: 1 to 120 minutes)
Battery life: Approximately 600 hours*4of continuous use (battery type and
operating condition dependent)
Dimensions: Approximately 150(H) x 61(W) x 42(D) mm (not including
connector part)
Weight: Approximately 220 g (including batteries)
EMC Compliance:
EMI (Emission): EN 61326-1 Class B
Test Item
Electromagnetic radiation disturbance
FrequencyRange
30 to1000 MHz
Basic Standard
CISPR16-1and 16-2
T0101.EPS
EMS (Immunity): EN 61326-1 Table 2 (For ise in industrial locations)
Test ItemNo.
1Electrostatic
discharge
Test SpecificationBasic Standard
IEC61000-4-2
Performance
Criteria*
*A:Normal performance withinthe specificationlimits:±20%ofthe measuredvalue.
B:Temporarydegrationorless offunctionorperformance which is self-recoverable.
** Displayvalue maybe affectedby strongelectromagnetic field.
A
4kV (contact)
8kV (air)
A
2.0to4.0GHz,
3V/m (unmodulated)
80%AM(1kHz)
2RF amplitude
modulated
electromagnetic field IEC61000-4-3
B**
80to1000 MHz,
10V/m (unmodulated)
80%AM(1kHz)
A
1.4to2.0GHz,
10V/m (unmodulated)
80%AM(1kHz)
T0102.EPS
*1: Display range is from -2 to 10 pH.
*2: Display range is from-10 to 1208C.
*3: When a needle type or test tube size pH sensor is used.
*4: When alkaline batteries are used.

IM 12B03D01-01E 1-3
1.Outline
1.3 When You Receive the PH71 Meter Package
Confirm that you received all package components of the PH71 meter you ordered
referring to the Model and Suffix Code and the item list in Section 1.4, “PH71 Meter
Kit.” Carefully inspect the meter and sensor, referring to Section 1.5, “PH71 Meter —
Part Names and Functions” and Section 1.6, “Sensors — Types, Part Names and
Functions.” Particular attention should be taken:
• Not to lose a wetting cap attached on the sensor tip. This cap is needed for
storage.
• Not to twist or pull the cable.
• Not to hit or drop the meter.
• Not to get connectors dirty.
• In handling of standard solutions and reagents. Solution bottles should be stored
in a cool, dark place and tightly capped after use. Once opened, the contents of a
bottle should be used early. Dispose of solutions in accordance with local
regulations.

IM 12B03D01-01E
1-4
1.Outline
1.4 PH71 Meter Kit
PH4 PH7
KCl
12 13
15
14
16
11
Instrument Card
78910
1
2
5
6
4
3
Quick Manual
Note:On the name plate of sensor,Modeland SuffixCode of sensor itself(PH72SN- -AA)
is indicated.(See Section 1.6.)
PersonalpH/ORPmeter
Without sensor
WithKCl replenish-free type combination pHsensor (cable length: 0.75m)
WithKCl replenish-free type combination pHsensor (cable length: 3m)
WithKCl refillable type combination pHsensor (cable length: 0.75m)
WithKCl refillable type combination pHsensor (cable length: 3m)
Withneedle type pHsensor (cable length: 0.75m)
Withtest tube size pHsensor (cable length: 0.75m)
Japanese
English
Always -AA
PH71
Sensors -00
-11
-13
-21
-23
-32
-33
Label-J
language -E
--AA
Specification1to6in common,plus:
None
7,11,12,13,14
7,11,12,13,14
8,11,12,13,14,15,16
8,11,12,13,14,15,16
9,11,12,13,14,15,16
10,11,12,13,14,15,16
Items Included
ModelSuffixCode
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
No. PersonalpHmeter
Drybatteries,2xAA batteries
User's Manualand Quick Manual
Non-slippads (2pcs)
Hand strap
Instrument Card
KCl replenish-free type pHsensor
KCl refillable type pHsensor
Needle type pHsensor
Test tube size pHsensor
Cotton swabs for sensor cleaning
pH4standard solution (50ml)
pH7standard solution (50ml)
Calibration bottles (2bottles)
KCl fillingsolution (3.3mol/l,50ml)
Syringe (5ml)
Item
F010401.EPS

IM 12B03D01-01E 1-5
1.Outline
1.5 PH71 Meter — Part Names and Functions
PERSONAL
pH METER
2004.
PH71
S1.0
E000001
MODEL
No.
STYLE
Sensorcable connector
Display
Keypad
O-ring
Connectiontoadedicated
pH sensor.
pH andtemperature
simultaneously.
Handstrap
attachment points
Nameplate
Batteryboxcover fixingscrew
F010501.EPS

IM 12B03D01-01E
1-6
1.Outline
1.6 Sensors — Types, Part Names and Functions
Sensors available for use with the Model PH71 Personal pH Meter are: general-purpose
pH sensors (KCl replenish-free and KCl refillable types), needle type pH sensor, and test
tube size pH sensor. Check the Model and Suffix Code on the name plate to identify the
type of your sensor.
pH sensor for Personal pH/ORP meter
For PH71, PH72;KCl replenish-free type combination pH sensor (cable length: 0.75 m)
For PH71, PH72;KCl replenish-free type combination pH sensor (cable length: 3 m)
For PH81, PH82;KCl replenish-free type combination pH sensor (cable length: 0.75 m)
For PH81, PH82;KCl replenish-free type combination pH sensor (cable length: 3 m)
For PH71, PH72;KCl refillable type combination pH sensor (cable length: 0.75 m)
For PH71, PH72;KCl refillable type combination pH sensor (cable length: 3 m)
For PH81, PH82;KCl refillable type combination pH sensor (cable length: 0.75 m)
For PH71, PH72;needle type pH sensor (cable length: 0.75 m)
For PH71, PH72;test tube size pH sensor (cable length:0.75 m)
For PH82;needle type pH sensor (cable length: 0.75 m)
For PH82;test tube size pH sensor (cable length:0.75 m)
Always -AA
*
1 : Part number of PH81, PH82 (previous models).
*
2 : Waterproofing is not guaranteed if you use PH82-type sensor in conjunction with PH71 meter.
PH72SN
-11
-13
-18
-19
-21
-23
-28
-32
-33
-38
-39
-AA
Specification
K9220YA
K9220YB
K9220YC
K9220YG
K9220YJ
RemarksModel SuffixCode
Example of Name Plate
Model and SuffixCode for pH Sensors
F010601.EPS
*
1
*
2
*
2
*
2
*
2
*
2
S1.0
000001-11-AA
STYLE
Made in Japan
MODEL
SUFFIX NO.
PH72SN
F010602.EPS
KCl replenish-free type combination pH sensor
Sensor body
Sensor grip
Sensor grip
Fill hole for KCl fillingsolution
Fill hole plug
Glass electrode
(Platinum electrode)
Glass electrode
Sensor cable
Waterproof cover
Connector
Name plate
KCl refillable type combination pH sensor
Wettingcap
Wettingcap
Sensor body
Sensor cable
Waterproof
cover
Connector
Name plate
Protective cover
Liquid
junction
Temperature element
Liquidjunction
Temperature element
Prevents water ingress
that may cause
insulation failure.
Measures pH
values.
Removedonly
duringcleaning.Measures solution temperature
andcompensates for temperature
effect on pH electrode.
Usedto prevent glass electrode from dyingout.Duringstorage this cap
with cotton wadmoistenedwith water shouldbe attachedto electrode tip.
Connection to pH
meter.Plastic body that can withstand
temperature up to 80°C.
Provides electrical contact
between internal reference
electrode andsample solution.
3.3mol/l KCl solution is used.
Prevents fillingsolution from
leakingfrom fill hole during
storage.Always unplugged
duringmeasurement.
Protective cover
*1
*1
*1
PH71- 21 - - AA
PH71- 23- - AA
PH71- 11 - - AA
PH71- 13- - AA
(PH72SN-11-AA,
PH72SN-13-AA )
*1
(PH72SN-21-AA,
PH72SN-23-AA )
*1:On the name plate of sensor,Model andSuffixCode of sensor itself (PH72SN- -AA)is indicated.(See Section 1.6.)

IM 12B03D01-01E 1-7
1.Outline
1.7 Options (Available Separately)
The following options are available for the Model PH71 Personal pH Meter for your
convenience. When ordering, specify the part number.
Sensor stand
(Part no. : K9220XN)
Soft carryingcase
(Part no. : B9269KJ)
pH 9 Standard solution
(Part no. : K9220XF)
Holds a sensor when pH meter
is used on the table. Made of
rustproofstainless steel.
Used for calibration when
anticipated pH value ofsample
solution is alkaline. (50ml)
Asoft blackcarryingcase holds
pH meter and sensor.
Unit: mm
Approx. 30
Approx. 140
Approx. 280
F010701.EPS

IM 12B03D01-01E
1-8
1.Outline
1.8 Spare Parts
O-ring and gasket set
(Part no. : K9654AY)
2gaskets for batterybox
2O-rings for connector
Capset
(Part no. : K9220ZY)
Used for sensor.
1protective cover
1wetting capF010801.EPS
pH9 Standard solution
(Part no. : K9084KH)
pH7Standard solution
(Part no. : K9084KG)
pH4 Standard solution
(Part no. : K9084KF)
Used for calibration. (250ml)
Used for calibration. (250ml)Used for calibration. (250ml)
Calibration bottle
(Part no. : K9220WW)
KClsolution
(Part no. : K9220XH)
Used during calibration. 210-ml
bottles.
Used to replenishKClrefillable
type sensor. 3.3mol/l,2bottles x
50ml

IM 12B03D01-01E 1-9
1.Outline
O-rings and gaskets are important parts to ensure that the PH71 meter is water resistant.
Replace these parts as required. Refer to Section 6.7, “Storage and O-ring/Gasket
Replacement” for replacement.

IM 12B03D01-01E
1-10
1.Outline

IM 12B03D01-01E 2-1
2.Preparation
2. Preparation
2.1 Installing the Batteries
Install the batteries first.
CAUTION
Select a relatively moisture-free location when installing batteries in the meter.
When installing batteries, observe correct polarity (battery orientation). Failure to do so
may damage to the meter.
Remove batteries from the meter if it is to be stored for an extended period of time.
Do not leave dead batteries in the meter. They may leak and cause meter failure or
erratic operation of the meter.
When replacing batteries, replace both batteries at the same time. If only one battery is
replaced, the new battery may discharge into the old battery, which may leak chemicals
and damage the meter.
If the battery box gasket is damaged or dirty then the unit may no longer be waterproof;
replace the gasket in this case.
F020101.eps
Press with
your fingers
Gasket
Batteries
(1) Loosen the screw holding the battery
box cover using a coin or similar
object.
(2) Remove the battery box cover, and
then install the batteries observing
polarity diagram inside.
(3) Make sure the gasket on the inside
rim of the battery box is free of
foreign material.
(4) Put the cover back on. Insert the tabs
on the top of the cover into the slots
at an angle of at least 458and lower
the cover into position.
(5) Press the both ends of the cover down
with your fingers and tighten the
screw to fix the cover onto the unit
using a coin or similar object.
Note:Do not attempt to tighten further
when you feel resistance before the
cover is fastened in place. Loosen
the screw once and retighten.
458or more

IM 12B03D01-01E
2-2
2.Preparation
2.2 Connecting the Sensor Cable
Connect the sensor cable.
CAUTION
Connect the sensor cable in a place free from moisture.
When connecting the sensor cable, tighten by turning only the silver locknut, do not turn
the cable or waterproof cover. Also take care not wet or contaminate the connector.
Sensors for the PH81 or PH82 meters can be connected. When used in conjunction with
the PH71 meter, however, water resistance is not guaranteed. This is due to the different
construction of the connector cover.
F020201.eps
O-ring
(1)Pull the waterproof cover along the
sensor cable away from the
connector to expose the locknut.
(2)Connect the connector to the meter
body*. Then tighten firmly by
turning only the locknut.
* Align the slots of the sensor cable
connector with the posts of the
connector on the meter.
(3)Move the waterproof cover toward
the connector until it contacts with
the O-ring* on the meter body.
* Make sure that the O-ring is free of
foreign material.
(4)Push and rotate the waterproof cover
1/4 turn (90 degrees) clockwise to
lock into place.
Locknut
(Silver)
Waterproof cover
(1)
(2)
(4)
(3)
Note: It is recommended that the sensor be kept connected to the meter to avoid
contamination of the connectors.

IM 12B03D01-01E 2-3
2.Preparation
2.3 Setting the Date and Time
After installing the batteries, set the date and time. Note that if the power is turned off
before completing minute setting, start with the date setting when you turn on the power
next time. By replacing the batteries, the date setting is not affected but the time setting
is. So the time must be reset.
Note: If a sensor cable is not connected to the meter, fluctuating readings or an error
message may appear. Before pressing
POWER
key, make sure that a sensor has
been connected.
• Setting Procedure
After installing the batteries, press and hold
POWER
key for at least one second. All
LCD segments appears momentarily and then the date setting display starts
automatically. Set year, month, day, hours, and minutes following the flowchart below.
Note: If you attempt to abort the setting procedure before completing, the meter will
beep three times and reject the attempt. Continue until the minute setting is
completed.
F020301.EPS
for at least 1sec.
Press
to set
to confirm
to set
to set
to confirm
to confirm
to set
to confirm
Year setting
Daysetting Hour setting (24-hour format)
Monthsetting
Minute setting
After
several
seconds
After
several
seconds
POWER
F/ENT
F/ENT F/ENT
F/ENT
to set to confirm
or
F/ENT