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YOKOGAWA PH72, User Manual

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YOKOGAWA PH72 User Manual Download Page 6

IM 12B03D02-01E

Toc-1

Contents 

CONTENTS

Preface ..........................................................................................................................1
1. Outline ................................................................................................................ 1-1

1.1 Features ..........................................................................................................................1-1

1.2  Specifications

 ..................................................................................................................1-2

1.3  When You Receive the PH72 Meter Package ................................................................1-4

1.4  PH72 Meter Kit ................................................................................................................1-5

1.5  PH72 Meter — Part Names and Functions ....................................................................1-6

1.6  Sensors — Types, Part Names and Functions...............................................................1-6

1.7  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 ..............................................................................................2-2

2.4  Selecting pH or ORP Measurement................................................................................2-3

2.5  Wetting Cap .....................................................................................................................2-4

2.6  Manual Temperature Setting ...........................................................................................2-4

2.7  pH Calibration ..................................................................................................................2-4

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 ......................................................................................................4-2

4.2  Manual Calibration ..........................................................................................................4-4

5.  Keypad and Display Functions ........................................................................ 5-1

5.1  Keypad Functions ............................................................................................................5-1

5.2  Display Items ...................................................................................................................5-2

5.3  Function Mode .................................................................................................................5-4

6. Maintenance ....................................................................................................... 6-1

6.1  For Optimum Meter Performance ...................................................................................6-1

6.2  pH Electrode Cleaning ....................................................................................................6-1

6.3  Sensor Replacement .......................................................................................................6-3

6.4  Rehydrating the Glass Electrode ....................................................................................6-3

6.5  Point to note when performing calibration or measurement ...........................................6-3

6.6  Replenishing the Electrode with Filling Solution (KCl solution) ......................................6-4

6.7  Cleaning and Drying Connectors ....................................................................................6-5

6.8  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 .............................................................................................................7-5

8.  ORP Meter .......................................................................................................... 8-1

8.1  ORP Measurement ..........................................................................................................8-1

8.2  Maintenance of ORP Sensors.........................................................................................8-2

8.3  Checking the ORP Sensor ..............................................................................................8-2

9.  Technical Information ........................................................................................ 9-1

9.1  Measurement Principle of pH Meter (Glass Electrode Method) .....................................9-1

9.2  Relationship between EMF of Glass Membrane and pH Value .....................................9-2

9.3  Temperature Compensation ............................................................................................9-4

9.4  The Asymmetry Potential ................................................................................................9-5

Summary of Contents for PH72

Page 1: ...User s Manual IM 12B03D02 01E Model PH72 Personal pH ORP Meter IM 12B03D02 01E 5th Edition ...

Page 2: ...sult 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 sur...

Page 3: ...bet Display Alphabet Display Display Numerals F00 ai All display segments n 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 n Flashing Displays Flashing messages numbers and digits on the display are indicated in gray in this manual Flashing state Lit s...

Page 4: ...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 m...

Page 5: ...ained in ANNEX II in DIRECTIVE 2006 66 EC How to remove batteries safely Refer to subsection 2 1 Installing the Batteries n How to dispose this product This directive is valid only in the EU This product complies with the WEEE Directive marking requirement This marking indicates that you must not discard this electrical electronic product in domestic household waste Product Category With reference...

Page 6: ... 5 1 Keypad Functions 5 1 5 2 Display Items 5 2 5 3 Function Mode 5 4 6 Maintenance 6 1 6 1 For Optimum Meter Performance 6 1 6 2 pH Electrode Cleaning 6 1 6 3 Sensor Replacement 6 3 6 4 Rehydrating the Glass Electrode 6 3 6 5 Point to note when performing calibration or measurement 6 3 6 6 Replenishing the Electrode with Filling Solution KCl solution 6 4 6 7 Cleaning and Drying Connectors 6 5 6 8...

Page 7: ... Alkaline Error 9 5 9 6 The Acid Error 9 7 9 7 Calibration Calculation 9 7 9 8 ORP Oxidation Reduction Potential 9 8 9 9 Reference Electrode 9 9 9 10Wetted Part Materials of Sensors 9 11 9 11 References 9 12 Appendix App 1 Revision Record i ...

Page 8: ...tic 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 o...

Page 9: ...bration Automatic 1 or 2 point manual Ambient temperature 0 to 50 C Wetted Material KCl replenish free type combination pH sensor Polypropylene resin sensor body protective cover Glass glass electrode temperature sensor protection tube Ceramics liquid junction Silicon rubber sensor seal KCl refillable type combination pH sensor PVC cable rigid polyethylene grip ethylene propylene rubber grip and c...

Page 10: ...ification limits 20 of the measured value B Temporary degration or less of function or performance which is self recoverable Display value may be affected by strong electromagnetic field EMC Regulatory Arrangement in Australia and New Zealand RCM EN 61326 1 Class B Table2 Korea Electromagnetic Conformity Standard Class B 한국 전자파적합성 기준 B급 기기 가정용 방송통신기자재 이 기기는 가정용 B급 전자파적합기기로서 주로 가정에서 사용하는 것을 목적으로 하며...

Page 11: ...s 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...

Page 12: ...KCl refillable type ORP sensor cable length 3 m With KCl refillable type combination pH sensor cable length 0 75 m KCl refillable type ORP sensor cable length 0 75 m Meter pnly without sensor 1 With KCl refillable type combination pH sensor cable length 0 75 m 1 Japanese English Global except South Korea and Malaysia with batteries South Korea and Malaysia without batteries 2 PH72 Connecting 00 se...

Page 13: ...ously Hand strap attachment points Name plate Battery box cover fixing screw F010501 ai 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 ...

Page 14: ...able length 3 m Always AA OR72SN Type 41 43 48 49 AA Specification K9220YL Remarks Model Suffix Code 2 S2 0 000001 11 AA STYLE Made in Japan MODEL SUFFIX NO PH72SN F010602 ai KCl replenish free type combination pH sensor Sensor body Sensor grip Sensor grip Fill hole for KCl filling solution Fill hole plug Glass electrode Platinum electrode Glass electrode Sensor cable Waterproof cover Connector Na...

Page 15: ... 250 mL Used for calibration 250 mL Calibration bottle Part no K9220WW Quinhydrone reagent for ORP Check Part no K9024EC 3 3 M KCl solution Part no K9220XH Used during calibration 2 x 10 mL bottles Used to replenish KCl refillable type sensor 3 3 mol L 2 bottles x 50 mL Used to check ORP electrode 3 packs one pack for 250 mL solution Safety data sheet SDS https www yokogawa com library O rings and...

Page 16: ... 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 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 materia...

Page 17: ...nsor 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 conn...

Page 18: ...confirm to confirm to set to confirm Year setting Day setting Hour setting 24 hour format Month setting Minute setting After several seconds After several seconds POWER F ENT F ENT F ENT F ENT to set to confirm or F ENT 2 4 Selecting pH or ORP Measurement Upon completing the date and time setting the meter is ready for pH measurement The display shows a pH value with a pH unit to the left of the v...

Page 19: ...f the solution being measured and manually set the measured temperature into the PH72 meter for reliable measurement The procedure is described in Section 5 3 2 Manual temperature setting M tP panel Temperature compensation is performed based on a temperature shown on the display of the PH72 meter If a temperature shown on the display is different from the actual temperature of the sample being me...

Page 20: ...ve solutions such as a solution containing hydrofluoric acid 4 Remove stains from the PH72 meter body using a soft cloth or tissue If necessary use a neutral detergent 5 If an abnormal symptom occurs during measurement locate the cause of the problem and take corrective actions referring to Chapter 7 Troubleshooting 6 After measurement rinse off dirt or the sample solution from the sensor with wat...

Page 21: ...low Fill hole left open during measurement Protective cover Sample solution Level of sample solution KCl refillable type sensor must be immersed so filling solution level is above the level of sample solution Figure 3 2 How to Immerse the KCl Refillable Type Sensor Bubbles trapped in the glass electrode tip may interfere with accurate measurement Before taking measurements check the electrode tip ...

Page 22: ...el Clock panel MEAS MEAS MEAS day month year Solution temperature pH value or mV hour minute 3 4 Saving a Measured Value There are two ways to save a measured value holding temporarily and storing as a record in nonvolatile memory Measured values stored in nonvolatile memory are not deleted even by replacing the batteries 1 HOLD If HOLD key is pressed during measurement the currently measured valu...

Page 23: ...ill be displayed If is displayed before the data number has reached 300 run defrag referring to Section 5 3 15 Defrag memory DFLG panel This will free up memory occupied by deleted data allowing data to be stored newly To check stored data refer to Section 5 3 1 Display stored data dAt panel Pressing DATA or MEAS key while mark is flashing cancels data storage and returns the meter to measurement ...

Page 24: ...needed Otherwise saved calibration results may be changed 3 Temperature of standard solutions should be close to that of measuring solutions in normal condition The gap of temperature between those solutions may result in inaccurate measurement Before Calibration The following should be checked and set before calibration 1 Contamination of the sensor Make sure that no dirt or deposits are present ...

Page 25: ...utions being used and calibrates itself using values of Table 4 1 Two types of standard solutions are preprogrammed NIST solutions prepared in accordance with Japanese standards factory default and US solutions prepared in accordance with the U S standards If NIST is selected the meter recognizes standard solutions with pH 2 4 7 9 and 12 The meter recognizes standard solutions with pH 4 7 and 10 i...

Page 26: ...int is complete F ENT Auto calibration in progress 2nd point Auto calibration at 2nd point is complete Calibration at 2nd point F ENT Std sol Water Wash sensor with water thoroughly or wash in water in beaker Wait until reading stabilizes Wipe off washing water from sensor thoroughly and then immerse sensor in standard solution Std sol Water Wash sensor with water thoroughly Wait until reading sta...

Page 27: ... solution temperature Std sol Water Wait until reading stabilizes Wipe off washing water from sensor thoroughly and then immerse sensor in standard solution to select auto calibration AUto After a few seconds Thermometer Wash sensor with water thoroughly or wash in water in beaker For 2 point calibration continue the procedure in the same way as Example 1 The difference between Example 1 and 2 is ...

Page 28: ... standard solutions as the same calibration point That is the second calibration result will override the first calibration value resulting in 1 point calibration 2 When using alkaline standard solutions use the standard solution with lower pH for the first point calibration If not may appear l Procedure Example 3 Manual calibration F0403 ai POWER CAL Prompting F ENT F ENT Manual calibration is co...

Page 29: ...tion continue the procedure following the dotted line When using a sensor without a built in temperature element needle type or test tube size pH sensor enter the temperature of standard solution following the procedure described in Section 4 1 Example 2 ...

Page 30: ...lue Moves to function mode or confirms data entry Holds the currently measured value Stores the currently measured value in memory 5 1 Keypad Functions POWER Power On Off key Pressing and holding this key for at least one second when nothing is displayed on the LCD will turn the meter on The meter will be turned off by pressing and holding this key for at least two seconds when the meter is on If ...

Page 31: ...des will return the meter to measurement mode If you want to cancel any operation press this key to return to measurement mode Setting change keys Used to change settings F ENT Entry key Pressing this key during measurement moves the display to function mode refer to Section 5 3 Function Modes This key is also used to confirm data entry Beep sound When a key is pressed the meter acknowledges it us...

Page 32: ...st tube size pH sensor is connected to the meter refer to Section 2 6 Manual temperature setting 4 Data mode Appears when measured data are stored or when stored data are accessed refer to Section 5 1 Keypad Functions and Section 5 3 1 Display stored data dAt panel 5 HOLD mode Appears while measured data are being held temporarily refer to Section 5 1 Keypad Functions 6 Calibration mode Appears du...

Page 33: ...key anytime Table 5 1 Function Mode Item List Item Description Default 2 For details refer to dAt Display stored data no dAtA Item 1 M tP Manual temperature setting 25 C Item 2 PV U Set measurement unit pH Item 3 dEL A Delete all stored data Item 4 dAtE Date setting 2004 1 month 1 day Item 5 tIME Time setting 0 hour 0 minute Item 6 ALM Alarm time setting oFF Item 7 A oFF Set Auto Power Off time 20...

Page 34: ... flashing Use keys to switch to flashing and then press F ENT key The stored data with the number to the left of dEL will be deleted Data Numbering after Deletion The number displayed at the bottom left indicates the stored data number relative to the beginning of the data store This number does not necessarily represent the number of stored data If a data item is deleted item numbers of data that...

Page 35: ...F ENT F ENT F ENT F ENT F ENT DATA DATA DATA DATA DATA Stored measurement data to display other data Latest data Year data item was stored Day and month data item was stored Delete stored data panel Delete stored data Time data item was stored When no stored data ...

Page 36: ...re element The setting range is from 10 0 to 110 0 C F050302 ai to set to confirm F ENT F ENT 3 Set measurement unit PV U panel Used to set a pH unit for pH measurement or a mV unit for ORP measurement F050303 ai to toggle to proceed F ENT to confirm F ENT 4 Delete all stored data dEL A panel Used to delete all stored data Press F ENT key on the flashing dEL A panel will be flashing Use keys to se...

Page 37: ...the time and press F ENT key to confirm each entry F050306 ai Hour setting 24 hr clock Minute setting F ENT F ENT F ENT 7 Alarm time setting ALM panel Used to enable disable the alarm clock and set the alarm clock in minutes and seconds Use keys to select the desired alarm cycle 7 days everyday 5 days weekdays or once See Item 5 Time setting tIME panel for setting the time for alarm The alarm soun...

Page 38: ...sounds once at preset time F ENT F ENT F ENT 8 Set Auto Power Off time A oFF panel Used to set the automatic power off time The meter turns off power automatically if no key is pressed during this preset time The time range is from 1 to 120 minutes If 0 is set the Auto Power Off function will be disabled Use the meter taking care to conserve the batteries F050308 ai F ENT to set to confirm F ENT ...

Page 39: ...he type of standard solutions NIST or US The factory default is NIST When using standard solutions prepared in accordance with the Japanese standards use the meter with the factory default of NIST Select US only when using standard solutions prepared in accordance with the U S standards refer to Chapter 4 Calibration F050310 ai to toggle F ENT to confirm F ENT 11 Initialize calibration parameters ...

Page 40: ... but this individual deletion does not free up memory occupied by deleted data Therefore may be displayed even though less than 300 data are stored In such a case use the defrag function to consolidate data and free up the space occupied by deleted data thereby allowing up to 300 data to be stored While memory defrag is in progress do NOT turn off the power In addition before starting memory defra...

Page 41: ...IM 12B03D02 01E 5 12 5 Keypad and Display Functions F050314 ai to toggle to proceed F ENT to cancel F ENT to execute F ENT After a few seconds may not appear if deleted data amount is small ...

Page 42: ...ied standard solutions pH 2 4 7 9 10 or 12 Measurement Sample solution requirements pH range 0 to 14 pH Temperature 0 to 80 C 0 to 100 C when using needle type or test tube size pH sensor Maintenance After measurement rinse off remaining sample solution from the electrode thoroughly Storage Avoid a place with high temperature and humidity Keep the wetting cap moisten the cotton wad in the cap with...

Page 43: ...sing a Toothbrush l Chemical Contaminants Chemical contaminants can affect the electrode performance even though the electrode appears to be clean If appears on the display soak the electrode in dilute hydrochloric acid approximately 0 1 mol L 1 to 2 pH for 10 to 20 minutes this process is called acid cleaning Since an electrode deteriorates gradually in service its performance cannot be recovered...

Page 44: ...h is displayed replace the sensor 6 4 Rehydrating the Glass Electrode A dry glass electrode gives fluctuating pH readings If a glass electrode has dried up soak it in water tap water for 1 to 2 hours or longer to rehydrate The sensor will give stable pH readings 6 5 Point to note when performing calibration or measurement When the internal electrode Ag AgCl of the glass electrode is exposed to sun...

Page 45: ...n little by little during measurement When the level of filling solution drops to the level shown in Figure 6 3 replenish with a 3 3 mol L KCl solution supplied CAUTION A syringe tip is sharp Handle with care F0603 ai How to fill using syringe Fill hole for KCl solution Syringe supplied Filling solution level Protective cover Replenish when filling solution level drops to the level shown above 20m...

Page 46: ...lean the connector with a dry cloth or a cloth moistened with anhydrous alcohol If necessary use a dryer Wipe off stains and or moisture on meter connector with a dry cloth Check that there are no stains on the O ring O ring Hot air Use a dryer if necessary to remove moisture from connector of sensor cable F060601 ai CAUTION Use anhydrous alcohol to clean the connectors so no moisture remains Dry ...

Page 47: ...ining Contamination may cause deteriorated insulation of connectors or poor water resistance by the O ring 3 Do not place any object on top of the sensor or on the top of the PH72 meter F0604 ai Wetting cap Protective cover Attach wetting cap containing cotton wad moistened with a few drops of water For KCl refillable type sensor seal fill hole with plug Figure 6 4 Sensor Storage Condition l Stora...

Page 48: ...herwise water resistance may not be assured 1 Replacing the O ring Install the O ring on the cylindrical flat part of the connector as shown below O ring F060701 ai 2 Replacing the Gasket Install the gasket on the groove on the battery box so the raised part fits in place as shown below The gasket is symmetrical right to left and front to back Gasket Raised part PH72 meter top F060702 ai ...

Page 49: ...IM 12B03D02 01E 6 8 6 Maintenance ...

Page 50: ...les 3 Failure If any trouble occurs determine the cause and take corrective actions referring to Section 7 2 If the trouble cannot be fixed contact your nearest Yokogawa sales office Symptom Expired consumables Unstable reading Abnormal reading Error message Electrode Batteries Improper maintenance Improper calibration Stained electrode Dry glass electrode Deteriorated insulation of connectors Met...

Page 51: ... after 3 minutes has elapsed in calibration an Err1 message will appear Possible Causes Dry electrode Clogged liquid junction Insulation failure in electronics Sensor immersed improperly Corrective Actions Leave the sensor in a standard solution until the reading stabilizes and then try recalibration Remove dirt or deposits from the liquid junction see Section 6 2 Remove stain or moisture from the...

Page 52: ...erature Appears during calibration In the Model PH72 Personal pH ORP Meter standard solution data NIST and US are preprogrammed During automatic calibration the meter recognizes standard solutions being used based on these data If standard solutions other than the preprogrammed ones are used an Err3 message will appear It will also appear if the slope is outside the range of 65 to 125 Possible Cau...

Page 53: ...ter for 1 to 2 hours or longer to rehydrate see Section 6 4 Remove dirt or deposits from the sensor see Section 6 2 5 Err5Out of temperature measuring range Appears during measurement With the Model PH72 Personal pH ORP Meter a general purpose sensor can be used in the temperature range of 0 to 80 C and a needle type or test tube size sensor in the temperature range of 0 to 100 C If the operating ...

Page 54: ...wledge a key press can be enabled disabled Refer to Section 5 3 9 Set beep on off bZ o panel appears This indicates that the electrode has deteriorated The electrode may be used continuously even after this mark appears If a or message appears in addition to this mark however replace the sensor with a new one immediately This mark will also appear when deteriorated or poor quality standard solutio...

Page 55: ...e compensation assuming that the solution temperature is 25 C Therefore the bigger the difference between the actual temperature of the solution and 25 C the bigger the error between the displayed measured value and the true value For reliable measurement replace the sensor with a good one This mark will also appear if the sensor is not connected properly Make sure that the connectors are securely...

Page 56: ...pH ORP Meter is pH Press F ENT key and follow the procedure described in Section 5 3 3 Set measurement unit PV U panel to move to the display with mV unit F0801 ai Figure 8 1 Example of Displayed ORP Value Immerse the sensor in a sample solution and read after the reading has stabilized To hold a measured value press HOLD key Press DATA key to save a measured value see Section 3 4 Note Unlike pH s...

Page 57: ...e force to the glass sensor or it may break Replenishment of Electrode Filling Solution When the level of KCl filling solution drops replenish following the procedure in Section 6 6 8 3 Checking the ORP Sensor Use a check solution to verify that the ORP sensor operates properly The oxidation reduction potential of the check solution to be used should have been correctly determined by a normal ORP ...

Page 58: ...o 10 minutes 4 Read the mV value and solution temperature The mV reading at the solution temperature must be within the tolerance 640 mV shown in Figure 8 2 If it falls within the tolerance the sensor is normal If not clean the sensor following the procedure in Section 8 2 400 300 200 100 0 0 10 20 30 40 50 Temperature C Oxidation reduction potential mV Quinhydrone solution Tolerance F0802 ai Figu...

Page 59: ...IM 12B03D02 01E 8 4 8 ORP Meter ...

Page 60: ...tion A reference electrode has a constant potential irrespective of the pH of the test solution which is supported by potassium chloride KCl solution It prevents the reference electrode from making contact with the test solution but itself has electrical contact with the test solution through the liquid junction A voltmeter measures the potential difference between the electrodes As the membrane r...

Page 61: ...of the hydrated layer and of the solution This boundary potential e is expressed from the Nernst equation as follows R gas constant 8 3145 J mol K T absolute temperature t C 273 15 K F Faraday constant 9 6485 x 10 C mol C potential at interface between glass and internal solution C potential at interface between glass and sample solution e Where pH C internal solution side 2 3026 R T F 9 1 i i i e...

Page 62: ...hip between millivolt and pH can be determined thereby the pH can be directly derived from the membrane potential difference as shown in Figure 9 3 Internal solution side Sample solution side Hydrated layers on glass Boundary layers i e S e H H F0902 ai Figure 9 2 Diagram of Glass Membrane 400 500 pH 2 0 E mV 300 200 100 0 100 200 300 400 500 4 6 8 10 12 14 F0903 ai Alkaline error Figure 9 3 Relat...

Page 63: ... 11 95 73 05 30 60 15 65 67 10 100 74 04 Table 9 1 presents the relationship between the temperature and the emf per pH unit and the relationship between the pH and the emf at each temperature is shown in Figure 9 4 Measurement without temperature compensation will result in measured pH values including errors as shown in Table 9 2 The PH71 meter automatically modifies the calibration line accordi...

Page 64: ... some potentials CS Ci develop depending on the thickness of the glass membrane heat treatment process service history or other factors This is called the real asymmetry potential In addition to this potential the difference in single electrode potential between the inner electrodes of the glass electrode and of the reference electrode and a liquid junction potential are collectively referred to a...

Page 65: ...Characteristics of Glass Electrode Test solution pH 9 0 20 40 60 Alkaline error mV 10 11 13 14 F0906 ai 12 Solution temperature at 25 C 3mol L Na 3mol L K 3mol L NH4 Figure 9 6 Ion Type vs Alkaline Error Test solution pH 9 0 20 40 60 Alkaline error mV 10 11 13 14 F0907 ai 12 Solution temperature at 25 C 3mol L Na 1mol L Na 0 1mol L Na Figure 9 7 Ion Concentration vs Alkaline Error ...

Page 66: ...perature at 25 C H2SO4 H3PO4 HCl Figure 9 8 Acid Type vs Acid Error 9 7 Calibration Calculation The PH71 meter is calibrated at 2 points using 2 standard solutions The first calibration is done so a certain line is drawn through the calibration point Figure 9 9 The second calibration is done so a line is drawn through the first and second calibration points Figure 9 10 One point calibration is a s...

Page 67: ...lectrons transferred If an inert electrode not react with substances in a solution or not corroded by a solution e g platinum or gold is immersed in a solution where oxidized and reduced forms of substances are present the electrode will acquire the potential that corresponds the ratio of activities of both forms of substances and reaches its equilibrium This potential is called the oxidation redu...

Page 68: ...nce electrode The relationship between the Ag AgCl electrode and the standard hydrogen electrode can be derived from the Nernst equation based on the following cell scheme Electrode Pt H2 Electrolyte solution Liquid junction or salt bridge KCl m AgCl Ag The reaction formula is AgCl e Ag Cl If a represents the activity from equation 9 6 E oxidation reduction potential when potential of standard hyd...

Page 69: ...ained from equation 9 10 the potential of the Ag AgCl electrode filled with a 3 3 mol L KCl solution E AgCl has the temperature characteristic for the standard hydrogen electrode as shown in Figure 9 12 To convert E AgCl to the value for the standard hydrogen electrode E oxidation reduction potential when reference electrode is SHE E oxidation reduction potential when reference electrode is Ag AgC...

Page 70: ...ody protective cover Glass glass electrode temperature element protective tube Ceramics liquid junction Silicon rubber sensor seal When cable is immersed KCl replenish free type Rigid polyethylene sensor grip PVC sensor cable Ethylene propylene rubber sensor grip cable connection Needle type pH sensor Glass sensor Test tube size pH sensor Glass sensor ORP sensor Polypropylene resin sensor body pro...

Page 71: ...984 Methods for Determination of pH of Aqueous Solutions Moore W J Basic Physical Chemistry Prentice Hall Inc U S A 1983 Donald Andrzej Julian Electrochemistry for chemists 2nd Ed Maruzen 2003 Bates R G Determination of pH theory and practice 2nd Ed John Wiley Sons Inc 1973 ...

Page 72: ... are shown Refer to the corresponding section in the body of the manual for details F01 ai POWER F ENT F ENT F ENT F ENT F ENT When turn on power First time used or after replace batteries MEAS MEAS MEAS Toggle display type or or or HOLD HOLD MEAS Temporary hold F ENT MEAS DATA DATA Storing data ...

Page 73: ...IM 12B03D02 01E App 2 Appendix F ENT F02 ai F ENT F ENT DATA DATA DATA DATA F ENT Function Mode or Display stored data F ENT Manual temperature setting F ENT F ENT F ENT Set measurement unit ...

Page 74: ...lete all stored data F ENT F ENT F ENT F ENT Date setting F ENT F ENT F ENT Time setting F ENT F ENT F ENT Alarm time setting F ENT F ENT Set Auto Power Off time Switching to Function Mode Reverting to Measurement Mode Measurement status Measurement status F ENT MEAS ...

Page 75: ...Function Mode Function Mode F04 ai F ENT F ENT Set beep on off F ENT F ENT Standard solution setting F ENT F ENT Initialize calibration parameters F ENT Check version number F ENT F ENT Defrag memory F ENT F ENT Set temperature unit ...

Page 76: ...nel Auto calibration in progress Auto calibration is complete Standard solution temperature Prompting Manual calibration is complete Measurement status Measurement status Automatic calibration Manual calibration CAL Automatic calibration for needle type or test tube size pH sensor CAL Auto calibration in progress Auto calibration is complete 2 point calibration F ENT F ENT F ENT F ENT F ENT F ENT ...

Page 77: ...IM 12B03D02 01E App 6 Appendix ...

Page 78: ... Section 6 5 P 6 3 4th Mar 2020 Change of accessories deletion of optional accessories move MSDS SDS to site revision of specifications etc full review 3rd Aug 2009 Change of information on EMC compliance P 1 2 2nd Apr 2008 Addition of information on EMC compliance P 1 2 Addition of CAUTION P2 2 Correction P 1 1 2 1 6 2 1 2 5 3 1 5 4 6 1 7 6 8 3 9 4 9 6 9 7 1st Oct 2004 Newly published ...

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