background image

Instruction Manual

765 Laboratory pH Meter

Summary of Contents for 765

Page 1: ...Instruction Manual 765 Laboratory pH Meter ...

Page 2: ... Meßgeräte GmbH Co P O Box 37 04 15 D 14134 Berlin Germany Tel 49 0 30 80191 0 Fax 49 0 30 80191 200 www knick de knick knick de Warranty Defects occurring within 3 years from delivery date shall be remedied free of charge at our works carriage and insurance paid by sender Accessories 1 year ...

Page 3: ...cription 1 2 Operation 2 Meter design 2 General information 3 Power on and start up 6 Parameter level 10 Calibration level 18 Diagnostics level 21 Trueline recorder output 30 Serial interface 31 Standard settings for ZU 0244 Lab Printer 32 Command set for the serial interface 32 3 Troubleshooting 41 Error messages 41 Appendix 45 Product line 45 Specifications 46 Buffer tables 49 Glossary 55 Index ...

Page 4: ...n safety Failure to follow these instructions may result in injuries Notes provide important information that should be strictly followed when using the device Typical representations Display example A gray representation of the display text indicates a flashing display Keys whose functions are described Markings in the text Keys are represented by bold faced text e g on standby ...

Page 5: ...ent of an opened device under voltage shall be carried out only by a skilled person who is aware of the hazards involved Remember that the voltage across accessible parts of the open device may be dan gerous to life Whenever it is likely that the protection has been impaired the device shall be made inoperative and secured against unintended operation The protection is likely to be impaired if for...

Page 6: ...rchtheCE markng wasaffixed L anneed apposition du marquage CE Knick ElektronischeMessgeräteGmbH Go KG Beuckestr 22 D 14163 Berlin erklären in alleiniger Verantwortung daßdiesesProdukt dieseProdukte declareunderoursoleresponsibility thatthe product products d6clarons sousnotreseuleresponsabilitÖ quele produit lesproduits Labor pH Meter 765 Opt Produktbezeichnung Product identification Designation d...

Page 7: ...ns of eleven different selectable buffer sets are provided for calibration Buffer rec ognition is automatic via Calimatic The calibration timer alerts you when the preset interval between two calibrations has expired Sensoface electrode monitoring checks the con nected electrode and provides information on the electrode condition Knick Fullcheck device self test checks the device functions at the ...

Page 8: ...Operation 2 Operation Meter design 1 2 Electrode connection 3 4 Temperature probe connection 5 DS connection 6 7 Recorder output 8 Interface connection 9 Power input 10 Sensoface display 11 13 Displays 12 14 Measurement symbols ...

Page 9: ...In the VIEW menu you can view all parameters In the EDIT menu you can also edit the parame ters Pressing opens the Diagnostics level On the Diagnostics level you can get information on the electrode condition view the current electrode data and perform a complete device self test The Sensoface menu lists the individual param eters of Sensoface automatic electrode monitor ing with the corresponding...

Page 10: ...t a complete record of the data stored Pressing or in measuring mode selects the measured variable for the left or right display respectively The corresponding measurement symbol appears on the right side of the display On the function levels these keys are used to select parameters When entering numerical parameters they are used to increment or decrement a numeral Pressing in the EDIT menu of th...

Page 11: ...aluated dur ing calibration Impedance dry out and the calibration timer are evaluated during measurement and in standby mode A summary of the individual results is expressed by three face symbols The electrode is in good condition The electrode is still usable but should be cali brated The electrode urgently requires calibration If the display does not change after calibration replace the electrod...

Page 12: ...simulator Power on and start up Mains supply The pH meter is designed for 230 VAC supply Option 363 115 V AC Connect the power input of the pH meter to a mains outlet using the included power cord If the pH meter is disconnected from mains clock and calibration timer are not affected reserve power approx 1 year Settings calibration and diagnostics data remain permanently stored Electrode connectio...

Page 13: ...ually selected temperature The deci mal point of the temperature display flashes If you use double platinum electrodes for voltamet rical indication of titrations Connect the banana plugs of the double platinum electrode to sockets 1 and 2 To connect the 10 µA polarization current to the double platinum electrode connect socket 5 with the inner pole of socket 1 e g using a banana plug with cross h...

Page 14: ...ostics data remain permanently stored The interface is deactivated Pressing switches the meter to mea suring mode At power on the meter performs a short check Simultaneous lighting up of all display segments measurement symbols and Sensoface displays Display of model name PH 765 Display of software version Display of nominal buffer values of selected buffer set Memory test To stop the short check ...

Page 15: ... is shown on the right side of the display You can choose any of the following vari ables pH value Electrode potential mV Temperature C Time A flashing point on the temperature display indi cates that no temperature probe is connected The meter now uses the manually selected tempera ture If you have connected a printer pressing in the measuring mode gives you a printout of the cur rently measured ...

Page 16: ...esponding submenu The VIEW menu automatically displays all parame ters Settings cannot be changed however To hold the display press To scroll one line forwards or backwards press or respectively In the EDIT menu you can view and edit all param eters Select the parameter you want to edit using or Press to start parameter editing To indicate that the parameter can now be edited the right display fla...

Page 17: ...uffer solutions to DIN 19 267 calibration buffer set 03 Therefore you must select buffer set 03 on the Parameter level Press to access the Parameter level Press to select the EDIT menu Press to open the EDIT menu Select buffer set parameter BUFF using Now press to change the buffer set The right display will flash Select buffer set 03 technical buffers to DIN 19 267 using par enter ...

Page 18: ...following the individual parameters and their possible settings will be explained Manual temperature 50 to 150 C If no temperature probe is connected the meter uses the manually selected temperature In this case the decimal point of the temperature display will flash in measuring mode Sensoface off on Display of Sensoface electrode monitoring can be turned on or off If Sensoface display is turned ...

Page 19: ... decimal point When the value changes slowly only the last digit will be suppressed When the value has stabi lized all digits will be displayed Only for meters with Option 346 Setting the nominal electrode zero point and slope Nominal zero pH 0 00 to 14 00 For special electrodes with differing nominal zero The entered zero point is taken as reference for Calimatic The exact zero point will be dete...

Page 20: ...rrors BUFF 00 Knick technical buffers pH 2 00 4 01 7 00 9 21 25 C BUFF 01 Mettler Toledo technical buffers correspond to Ingold technical buffers pH 2 00 4 01 7 00 9 21 25 C BUFF 02 Merck Riedel pH 2 00 4 00 7 00 9 00 12 00 20 C BUFF 03 DIN19267 pH 1 09 3 06 4 65 6 79 9 23 12 75 25 C BUFF 04 DIN19266 and NIST NBS pH 1 679 4 006 6 865 9 180 12 454 25 C BUFF 05 Merck Riedel pH 1 00 3 00 6 00 8 00 10...

Page 21: ...ext due calibration After approx 80 of the preset interval have expired the timer sets the Sensoface display from to After the total interval has expired the display is set to The timer is reset by calibration To turn off the timer enter 0 as interval time Recorder output pH mV C PRNT The recorder output can output pH value mea sured voltage or temperature With PRNT selected the recorder output se...

Page 22: ... You can directly print out measured values and records To connect the meter to a computer PC select PC The pH meter will be completely computer control lable All measured values and parameters will be retrievable via computer Print interval timer 0 1 to 999 9 min This step only appears if you have set the interface for printer control The print interval timer presets an interval for printout of c...

Page 23: ...Operation 17 Time Date Year End of VIEW menu End of EDIT menu ...

Page 24: ...You can stop calibration at any time by pressing The meter can only operate properly when the buffer solutions used correspond to the buffer set selected on the Parameter level Other buffer solu tions even those with the same nominal values may demonstrate a different temperature behavior This leads to measurement errors Immerse the electrode and temperature probe in the first buffer solution This...

Page 25: ...4 sec a mark is added to the tally beside the clock Stability check can be stopped by pressing However this reduces calibration accuracy Calibration with the first buffer is terminated Take the electrode and temperature probe out of the solution and rinse them thoroughly If you only want to perform a one point calibra tion press to stop calibration or select CAL2 NO using and press to exit the Cal...

Page 26: ... for the electrode Display of slope determined for the electrode End of calibration Printing calibration record If you have connected the meter to a printer you can print out a record of the last calibration Press to open the Calibration level Press to print out the complete record of the last calibration The meter will automatically return to measuring mode print ...

Page 27: ...n of the Diagnostics level using or Pressing gives access to the corresponding sub menu The Sensoface menu shows the states of the cri teria that control Sensoface display The Electrode Data menu shows the electrode data calculated during last calibration the calibration timer count and the electrode statistics The Knick Fullcheck menu provides a complete device self test to check the operability ...

Page 28: ...improvement can only take place after a calibration Here the Sensoface display provides information on zero and slope of the electrode For the exact zero and slope values refer to the Electrode Data menu Zero and slope of the electrode are okay Zero and slope of the electrode are still okay How ever the electrode should be replaced soon Zero and or slope of the electrode have reached values which ...

Page 29: ...can reduce the gel layer of the glass membrane This results in a longer response time The electrode gets sluggish The electrode promptly adjusts to the measured value The electrode adjusts slowly You should consider replacing it It may be possible to achieve an improvement by cleaning or in the case of an elec trode stored dry by watering The electrode adjusts very slowly to the measured value Cor...

Page 30: ...bration interval is still running Over 80 of the calibration interval have run out The calibration interval has been exceeded End of Sensoface menu Sensoface was specially designed for monitoring pH electrodes Since ORP electrodes have com pletely different characteristics they provoke in valid Sensoface displays Therefore you should disable Sensoface for ORP measurements Sensoface display can als...

Page 31: ...next calibration is requested by the timer The electrode statistics include the electrode zero slope and response time of the last three calibra tions with corresponding date and time In addition the data of the first calibration see Pg 15 per formed on this electrode are provided This allows you to evaluate electrode behavior over its whole life span Since the data are very comprehensive they sho...

Page 32: ...mined during last calibration Electrode zero determined during second last cali bration Electrode zero determined during third last calibra tion Electrode zero determined during first calibration Slope determined during last calibration Slope determined during second last calibration Slope determined during third last calibration Slope determined during first calibration ...

Page 33: ... play and keypad are checked and each result is displayed The tests run automatically Only during keypad testing you have to press the requested keys Longer testing periods are indicated by a little running clock on the right display Successful testing is confirmed by OK on the right display RAM test EPROM test EEPROM test Amplifier linearity test Using an integrated high precision reference the c...

Page 34: ...rcuit Amplifier linearity test is terminated The device takes a few seconds to bumplessly reconnect the electrode to the amplifier Display test All Sensoface indicators all seg ments of the two LED displays and all measure ment symbols light up Check whether really everything is lighting During keypad testing you are prompted to press the corresponding key Press Press Press Press Press Press ...

Page 35: ...ess End of device test Printing diagnostics record If you have connected the meter to a printer you can print out a record of the diagnostics Press to open the Diagnostics level Press to print out the complete diagnostics record print ...

Page 36: ...ent input variables If pH has been selected as output variable the out put voltage zero is at pH 7 For meters with Option 346 Nominal electrode zero and slope user defined the output voltage zero is at the selected nominal zero point If the recorder output has been set for printer con trol a voltage of approx 1 5 V lies across its output By short circuiting current approx 1 5 mA e g using a foot s...

Page 37: ...s are made on the Parameter level Baud rate 600 1200 2400 4800 9600 Bd Data format Protocol No protocol XON XOFF bidirectional handshake If not ready to accept data the meter transmits XOFF 13 H if ready to accept data XON 11 H Pin assignment The pH meter has a 9 pin D SUB connector con nector with pin contacts The metallic connector shell is connected to signal ground via a capacitor and provides...

Page 38: ...he pH meter Read commands always return a response Device function is not affected Write commands start with W They send com mands and parameters to the pH meter A write command modifies device settings or parameters The meter does not return a response Acknowl edgement of write commands can be enabled with the WPMSR1 command Then the meter will return CR carriage return 0D H after each write comm...

Page 39: ...int or comma floating or without Exponent E indicates exponent beginning or sign 1 to 3 digits Exponent may be omitted Example 1234567E 123 Exponent Numerical digits Sign Exponent beginning Mantissa Numerical digits Sign Reading measured values or results Com mand Response Unit Description RV0 xx xx pH pH value RV1 xxxxE 3 V Electrode potential RV2 xxx x C Pt100 Pt1000 temperature RVTRT xxxx hhmm ...

Page 40: ... 03 C range 50 to 150 C exceeded 04 Zero range pH 6 00 to 8 00 exceeded 05 Slope range 47 0 to 67 0 mV pH exceeded 09 Buffer cannot be identified 10 Identical buffers 20 Interface error 90 System failure Com mand Re sponse Description RSP xx Operating states 00 Measuring mode 01 Parameter mode 02 Calibration mode 08 Diagnostics mode Com mand Re sponse Description RSES x Sensoface display RSEZS x Se...

Page 41: ...te RSTERR x RAM test RSTERP x EPROM test RSTERE x EEPROM test RSTERA x Amplifier test RSTERI x Impedance test RSTERDI x Display test RSTERKY x Keypad test List of test results 0 ok display test executed 1 Test not executed 2 Defective Command Response Unit Description RSCPT xxxx hhmm Last calibration time RSCPD xxxxxx ddmmyy Last calibration date RSCPS xx Buffer set RSCP1NB xx xx pH Buffer 1 nomina...

Page 42: ...pe RSSTTR3 xxxx s Electrode response Record 2 second last calibration RSSTT2 xxxx hhmm Calibration time RSSTD2 xxxxxx ddmmyy Calibration date RSSTZ2 xx xx pH Electrode zero point RSSTS2 xxxxE 3 V pH Electrode slope RSSTTR2 xxxx s Electrode response Record 1 third last calibration RSSTT1 xxxx hhmm Calibration time RSSTD1 xxxxxx ddmmyy Calibration date RSSTZ1 xx xx pH Electrode zero point RSSTS1 xxx...

Page 43: ...0 Off 1 On RPDIDA x Displaymatic on off 0 Off 1 On RPAINA x Assignment for recorder output 0 pH 1 mV 2 Temperature 8 Input for printer control RPCASA xx Calibration buffer set 00 Knick technical buffers 01 Mettler Toledo technical buffers 02 Merck Titrisol buffers 03 Techn buffers to DIN 19 276 04 Standard buffers to DIN 19 266 05 Merck Titrisol buffers 06 Merck buffers ready to use 07 Ciba 94 08 ...

Page 44: ... meters with Option 346 Only for meters with Option 346 Nominal electrode zero and slope user defined Com mand Response Unit Description RPCA0NZ xx xx pH Nomminal zero RPCA0NS xxxxE 3 V pH Nominal slope RPCA0U xxxxE 3 V V iso isothermal potential ...

Page 45: ...on off 0 Off 1 On WPDIDA x Displaymatic on off 0 Off 1 On WPAINA x Assignment of recorder output 0 pH 1 mV 2 Temperature 8 Input for printer control WPCASA xx Calibration buffer set 00 Knick techn buffers 01 Mettler Toledo technical buffers 02 Merck Titrisol buffers 03 Techn buffers to DIN 19 276 04 Standard buffers to DIN 19 266 05 Merck Titrisol buffers 06 Merck buffers ready to use 07 Ciba 94 0...

Page 46: ... WCOM00 Switch to measuring mode WCCASTI Set first calibration only for Option 347 WCCAA1 Start calibration with 1st buffer WCCAA2 Start calibration with 2nd buffer WCDISLA0 Left display indicate pH WCDISLA1 Left display indicate mV WCDISLA2 Left display indicate temperature WCDISLATRT Left display indicate time WCDISRA0 Right display indicate pH WCDISRA1 Right display indicate mV WCDISRA2 Right di...

Page 47: ...ossible causes Electrode defective Too little electrolyte in electrode Electrode not connected Break in electrode cable Incorrect electrode connected e g ORP electrode The measured electrode potential is 1999 mV or 1999 mV Possible causes Electrode defective Electrode not connected Break in electrode cable The measured temperature is 50 C or 150 C Possible causes Temperature probe defective ...

Page 48: ...tion The meter identified two identical buffer solutions This message is only momentarily displayed during calibration Possible causes Same or similar buffer solution used for second calibration step Buffer solutions contaminated Electrode defective Electrode not connected Break in electrode cable Calibration was canceled after approx 2 minutes because the electrode drift was too large This mes sa...

Page 49: ...perature selected for manual temperature compensation Used electrode has different nominal zero point The electrode slope determined during calibration is out of range The electrode slope is 47 0 mV pH or 61 0 mV pH for Option 346 at 7 mV pH from nominal slope This message is displayed in mea suring mode after a calibration It can only be reset by a new calibration Possible causes Electrode worn o...

Page 50: ...erference during transmission System error message When a system error is found during the self test an error message is displayed Error in the configuration or calibration data or in the factory settings Possible causes Clock defective EPROM EEPROM or RAM defective Error in factory settings This error message normally should not occur as the data are protected from loss by multiple safety functio...

Page 51: ...C cable ZU 0152 Sensors and buffer solutions Combination pH Pt 1000 electrode glass with integrated Pt 1000 temp probe 0 to 80 C pH 0 to 14 SE 100 Combination pH electrode glass without temperature probe 0 to 100 C pH 0 to 14 SE 103 Pt 1000 temperature probe for fast response temperature measurements stainless steel 10 to 100 C ZU 6959 Calibration buffer set with Knick technical buffer solutions 2...

Page 52: ...c Accuracy 1 count pH 0 01 mV 0 1 0 3 mV C 0 3 K Input DIN 19 262 Input resistance 1 1012 Ohms Input current 1 10 12 A 20 C 45 C factor 10 Temperature coefficient 0 1 count K Electrode standardization Calimatic automatic calibration and buffer recognition German patent 29 37 227 For buffer tables see Apppendix Calibration ranges Zero pH 6 to 8 Slope 47 to 61 mV pH 25 C Option 346 Nominal zero slope...

Page 53: ...complete measurement elec tronics including recorder output segment and keypad test in Diag nostics mode automatic short check at power on Records Parameter record Calibration record Diagnostics record Records for QM documentation to ISO 9000 and GLP retrievable via interface printer or display Good Laboratory Practice Displaymatic Digit suppression according to signal change can be disabled Tempe...

Page 54: ...ibration data storage Automatic storage of calibration data self contained Data retention Parameters statistics and factory set tings 10 years EEPROM Clock Reserve power 1year battery backed Electrode statistics Storage of zero and slope of first cali bration as well as data of last three calibrations with time and date self contained output via interface to printer or computer EMC 2004 108 EC Emit...

Page 55: ...m w x h x d Weight Approx 2 kg C pH 0 2 03 4 01 7 12 9 52 5 2 02 4 01 7 09 9 45 10 2 01 4 00 7 06 9 38 15 2 00 4 00 7 04 9 32 20 2 00 4 00 7 02 9 26 25 2 00 4 01 7 00 9 21 30 1 99 4 01 6 99 9 16 35 1 99 4 02 6 98 9 11 40 1 98 4 03 6 97 9 06 45 1 98 4 04 6 97 9 03 50 1 98 4 06 6 97 8 99 55 1 98 4 08 6 98 8 96 60 1 98 4 10 6 98 8 93 65 1 99 4 13 6 99 8 90 70 1 99 4 16 7 00 8 88 75 2 00 4 19 7 02 8 8...

Page 56: ...8 93 65 1 99 4 13 6 99 8 90 70 1 99 4 16 7 00 8 88 75 2 00 4 19 7 02 8 85 80 2 00 4 22 7 04 8 83 85 2 00 4 26 7 06 8 81 90 2 00 4 30 7 09 8 79 95 2 00 4 35 7 12 8 77 C pH 0 2 01 4 05 7 13 9 24 12 58 5 2 01 4 04 7 07 9 16 12 41 10 2 01 4 02 7 05 9 11 12 26 15 2 00 4 01 7 02 9 05 12 10 20 2 00 4 00 7 00 9 00 12 00 25 2 00 4 01 6 98 8 95 11 88 30 2 00 4 01 6 98 8 91 11 72 35 2 00 4 01 6 96 8 88 11 67...

Page 57: ...8 88 11 43 75 1 11 3 04 4 73 6 77 8 86 11 31 80 1 12 3 05 4 75 6 78 8 85 11 19 85 1 12 3 06 4 77 6 79 8 83 11 09 90 1 13 3 07 4 79 6 80 8 82 10 99 95 1 13 3 08 4 82 6 81 8 81 10 89 C pH 0 1 666 4 010 6 948 9 464 13 423 5 1 668 4 004 6 951 9 395 13 207 10 1 670 4 000 6 923 9 332 13 003 15 1 672 3 999 6 900 9 276 12 810 20 1 675 4 001 6 881 9 225 12 627 25 1 679 4 006 6 865 9 180 12 454 30 1 683 4 0...

Page 58: ... 7 90 9 82 12 41 45 1 01 2 98 6 05 7 88 9 78 12 28 50 1 01 2 97 6 06 7 85 9 74 12 15 55 1 02 2 97 6 08 7 84 9 71 11 95 60 1 02 2 97 6 10 7 83 9 67 11 75 65 1 02 2 97 6 11 7 82 9 65 11 68 70 1 02 2 97 6 12 7 80 9 62 11 61 75 1 02 2 97 6 14 7 79 9 59 11 50 80 1 02 2 97 6 17 7 78 9 55 11 39 85 1 02 2 97 6 20 7 77 9 52 11 27 90 1 02 2 96 6 24 7 75 9 49 11 15 95 1 02 2 96 6 28 7 74 9 46 11 03 C pH 0 4 ...

Page 59: ... 93 9 73 55 2 05 4 05 6 91 9 68 60 2 08 4 10 6 93 9 66 65 2 075 4 105 6 925 9 615 70 2 07 4 11 6 92 9 57 75 2 045 4 135 6 925 9 545 80 2 02 4 15 6 93 9 52 85 2 03 4 175 6 95 9 475 90 2 04 4 20 6 97 9 43 95 2 05 4 225 6 99 9 385 C pH 0 4 00 7 12 10 32 5 4 00 7 09 10 25 10 4 00 7 06 10 18 15 4 00 7 04 10 12 20 4 00 7 02 10 06 25 4 00 7 00 10 01 30 4 01 6 99 9 97 35 4 02 6 98 9 93 40 4 03 6 98 9 89 4...

Page 60: ...765 Laboratory pH Meter 54 Appendix ...

Page 61: ...ation level the meter is adjusted for the connected electrode calibration You can con duct either a one or a two point calibration Calibration record Printout of all relevant data of the last calibration for documentation to GLP Start printout by pressing and Calimatic Automatic buffer recognition Prior to first calibra tion the used buffer set must be activated once on the Parameter level The pat...

Page 62: ...d wear enter Key for confirming entries First calibration During first calibration the electrode data are stored as reference values for electrode statistics GLP Good Laboratory Practice Guidelines for perfor mance and documentation of measurements in the laboratory Isothermal potential The isothermal potential is the potential at which the calibration curves for different temperatures in tersect ...

Page 63: ...slope value is retained Only one buffer solution is required for a one point cali bration par Key for activating the Parameter level Parameter level The Parameter level is divided into two submenus VIEW menu and EDIT menu The VIEW menu al lows to display all parameters without editing them The EDIT menu allows to view and edit all parame ters Parameter record Printout of all stored parameter setti...

Page 64: ...pedance and dry out of the electrode and the cal timer count Slope See Electrode slope Trueline The Trueline recorder output provides a pH cali brated analog output signal without disturbing volt age steps Two point calibration Calibration that takes account of zero point and slope of the electrode Two buffer solutions are re quired for two point calibration Zero point See electrode zero point ...

Page 65: ... messages 41 List of 34 F First calibration Activation 15 I Interface cable 32 K Keypad 3 L Lab printer ZU 0244 Standard settings 32 M Mains supply 6 Measuring mode 9 Menu structure 5 N Nominal electrode slope setting for Option 346 13 Nominal electrode zero setting for Option 346 13 O One point calibration 19 Operation Meter design 2 Option 346 13 P Package contents 1 Parameter record 12 Paramete...

Page 66: ...e 31 S Safety information III Sensoface 5 Sensoface menu 21 22 Sensor monitoring 5 Setting Remote interface 16 Short check at power on 8 Short description 1 Specifications 46 Standby mode 8 T Trueline recorder output 30 Two point calibration 19 V VIEW menu 10 ...

Reviews: