Knick 765 Instruction Manual

Knick 765 Instruction Manual

Laboratory ph meter

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Instruction Manual
765 Laboratory pH Meter

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Summary of Contents for Knick 765

  • Page 1 Instruction Manual 765 Laboratory pH Meter...
  • Page 2 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).
  • Page 3: Table Of Contents

    EC Declaration of Conformity ..........IV 1 The 765 Laboratory pH Meter Package contents .
  • Page 4: Information On This Instruction Manual

    765 Laboratory pH Meter Information on this instruction manual Warnings and notes Instructions marked with this sign must be strictly observed for reasons of your own safety! Failure to follow these instructions may result in injuries. Notes provide important information that should be strictly followed when using the device.
  • Page 5: Safety Information

    Safety information Be sure to read and observe the following instructions! Before connecting the device to the power supply, make sure that the voltage corre- sponds with the rating given on the rating plate of the device. Opening the device exposes live parts. Therefore, it shall not be opened. If a repair should be required, return the device to our factory.
  • Page 7: The 765 Laboratory Ph Meter

    • Power cord • This instruction manual Short device description • The Model 765 is used for pH and ORP measure- ments in the laboratory. • Temperature compensation is automatic using a Pt 100 or Pt 1000 temperature probe or manual by entering the temperature.
  • Page 8: Operation

    765 Laboratory pH Meter 2 Operation Meter design 1, 2 Electrode connection 3, 4 Temperature probe connection DS connection 6, 7 Recorder output Interface connection Power input ® Sensoface display 11, 13 Displays 12, 14 Measurement symbols Operation...
  • Page 9: General Information

    ® • With the Knick Fullcheck menu, a complete device self-test is performed. Operation...
  • Page 10 765 Laboratory pH Meter Pressing stores an entered parameter. If you have not made any changes, pressing enter selects the next parameter (instead of Pressing exits a function level and returns meas you to measuring mode. Pressing in measuring mode prints out the...
  • Page 11 Menu structure ® ® Sensoface automatic Sensoface automatic electrode monitoring pro- vides information on the electrode condition. Zero electrode monitoring point, slope and response time are evaluated dur- ing calibration. Impedance, dry-out and the calibration timer are evaluated during measurement and in standby mode.
  • Page 12: Power-On And Start-Up

    765 Laboratory pH Meter More detailed information on the indicated elec- trode condition and the individual parameter evalu- ations is given in chapter ”Diagnostics level” (see Pg. 21). ® Sensoface was specially designed for monitoring pH electrodes. Since ORP electrodes have com- pletely different characteristics, they provoke ®...
  • Page 13 Connection Socket Combination electrode Single sensing electrode Single reference electrode Temp probe of combination electrodes (Electrodes with integrated temp probe) Separate temperature probe 3, 4 If no temperature probe is connected, the meter uses the manually selected temperature. The deci- mal point of the temperature display flashes.
  • Page 14 • 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 • Memory test To stop the short check, press Do not disconnect the meter from mains if you do not use it.
  • Page 15 Measuring mode In measuring mode both displays indicate the respectively selected measured variable. The vari- able for the left display is selected using , for the right display using . The corresponding mea- surement symbol is shown on the right side of the display.
  • Page 16: Parameter Level

    765 Laboratory pH Meter Parameter level On the Parameter level all variable device parame- ters are set. Parameters are set in dialog mode using different menus. Activating parameter setting Press to exit measuring mode and access the main menu of the Parameter level. To exit Parame- ter level, press .
  • Page 17 Typical setting procedure The meter is factory set to calibration buffer set 01 (Mettler Toledo technical trade buffers). However, you want to calibrate using the technical buffer solutions to DIN 19 267, calibration buffer set 03. Therefore, you must select buffer set 03 on the Parameter level.
  • Page 18 765 Laboratory pH Meter Press to confirm your choice. Buffer set 03 enter will be stored and the next parameter displayed. Press to exit Parameter level. meas Printout of parameter record If you have connected the pH meter to a printer, you can print out all stored parameter settings.
  • Page 19 ® Sensoface was specially designed for monitoring pH electrodes. Since ORP electrodes have com- pletely different characteristics, they provoke ® invalid Sensoface displays. Therefore, you should ® disable Sensoface for ORP measurements. Sen- ® soface display can also be degraded when you use a pH simulator.
  • Page 20 765 Laboratory pH Meter Calibration buffer set (00 to 10) Select the buffer set with the buffer solutions you are using. The meter has stored eleven different calibration buffer sets. (see Buffer sets Pg. 49). BUFF –00– Knick technical buffers 2.00...
  • Page 21 First calibration (no / yes) With YES, all statistics data will be erased with the next calibration, and the new electrode data will be stored as First Calibration data. After calibration, this parameter will automatically reset to NO. You should always perform this step when replac- ing the electrode so that a new statistic is started for the new electrode.
  • Page 22 765 Laboratory pH Meter Baud rate (600 / 1200 / 2400 / 4800 / 9600) Here, you can select the interface transmission rate. Data format (8 NO / 7 EV / 7 OD) You can choose between: Data word length...
  • Page 23 Time Date Year End of VIEW menu. End of EDIT menu. Operation...
  • Page 24: Calibration Level

    Parameter level. The patented Calimatic then automatically recognizes the buffer solution in use, calculates zero point and slope of the electrode and adjusts correspondingly. In addition, the Model 765 measures the electrode response time during cali- bration. Activating calibration...
  • Page 25 During buffer recognition CAL 1 is flashing. The right display reads the measured temperature. When you use manual temperature compensation, the entered temperature is displayed. This is indi- cated by a flashing decimal point. The nominal value of the identified buffer solution is displayed for approx.
  • Page 26 765 Laboratory pH Meter Display of nominal buffer value for approx. 5 sec Check of electrode stability and response time Display of zero point determined 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.
  • Page 27: Diagnostics Level

    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 of the indi- vidual device components.
  • Page 28 765 Laboratory pH Meter ® ® Sensoface menu In the Sensoface menu you see the criteria that ® control Sensoface display. Each criterion is dis- played separately with the corresponding evalua- tion. This gives you important information on the ®...
  • Page 29 ® The Sensoface display provides information on the electrode’s response time. This is the time the electrode requires for delivering a stable measured value. The value determined during calibration. Wear and aging, but also wrong treatment (such as dry storage) can reduce the gel layer of the glass membrane.
  • Page 30 765 Laboratory pH Meter On the Parameter level, the calibration timer allows to preset a time interval for the next due calibration. The calibration timer keeps running in standby mode and with mains supply disconnected. The calibration interval is still running.
  • Page 31 Electrode Data menu The Electrode Data menu shows the values for zero and slope of the electrode calculated during the last calibration, the cal timer count, and the electrode statistics. Display of electrode zero determined during last calibration. Display of electrode slope determined during last calibration.
  • Page 32 765 Laboratory pH Meter Time of last calibration Time of second last calibration Time of third last calibration Time of first calibration Electrode zero determined during last calibration Electrode zero determined during second last cali- bration Electrode zero determined during third last calibra-...
  • Page 33 End of Electrode Data menu. ® ® Knick Fullcheck menu With the Knick Fullcheck menu, a complete device self-test is performed. The complete measuring cir- cuitry, measured value processing, memories, dis- play and keypad are checked and each result is displayed.
  • Page 34 765 Laboratory pH Meter Linearity test at -1500 mV Linearity test at -750 mV Linearity test at 0 mV Linearity test at +750 mV Linearity test at +1500 mV Test of impedance measuring circuit Amplifier linearity test is terminated. The device takes a few seconds to bumplessly reconnect the electrode to the amplifier.
  • Page 35 Press Press Press Press 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 print record.
  • Page 36: Trueline Recorder Output

    ® The Trueline recorder output was developed for ® the 765 Laboratory pH Meter. Trueline supplies an analog output signal without disturbing voltage steps, but being calibrated to pH. Galvanic output isolation is standard. Connected recorders and data acquisition systems thus do not have to be floating.
  • Page 37: Serial Interface

    Serial interface The Model 765 comes with an RS 232 interface. The interface is user-definable for direct control of a printer with serial input or for direct connection to a computer. The pH meter is completely computer controllable and all values and parameters can be read out.
  • Page 38: Standard Settings For Zu 0244 Lab Printer

    765 Laboratory pH Meter Interface cable Knick offers as accessory: • ZU 0245 interface cable for connecting the pH meter to the ZU 0244 Lab Printer. • ZU 0152 interface cable for connecting the pH meter to a computer (PC):...
  • Page 39 Message terminator Message terminators for read and write • Read: The pH meter terminates the string by ”CR” (carriage return <0D> H). • Write: The pH meter expects ”CR” or ”LF” (line feed <0A> H) or any combination of these as mes- sage terminator.
  • Page 40 765 Laboratory pH Meter Reading error messages Com- Response Description mand RSF1 First error message RSFA xx;xx;xx;... All active error messages List of error messages (xx): List of error messages (xx): pH range –2.00 to +16.00 exceeded mV range -2000 to +2000 mV exceeded °C range –50.
  • Page 41 Query keypad Com- Description mand sponse Query keypad Reading results of Knick ® Fullcheck self test Command Unit Description sponse RSTET xxxx [hhmm] Last Fullcheck/ time RSTED xxxxxx [ddmmyy] Last Fullcheck/date RSTERR RAM test RSTERP EPROM test RSTERE EEPROM test RSTERA Amplifier test...
  • Page 42 765 Laboratory pH Meter Command Response Unit Description RSCP2NB ± xx.xx [pH] Buffer 2: nominal value RSCP21 ± xxxxE–3 Buffer 2: electrode potential RSCP22 ± xxx.x [°C] Buffer 2: temperature RSCP2TR xxxx Buffer 2: response time Reading electrode statistics Com-...
  • Page 43 RPAINA Assignment for recorder output Temperature Input for printer control RPCASA Calibration buffer set Knick technical buffers Mettler Toledo technical buffers Merck Titrisol buffers Techn. buffers to DIN 19 276 Standard buffers to DIN 19 266 Merck Titrisol buffers...
  • Page 44 765 Laboratory pH Meter Only for meters with Option 346: Only for meters with Option 346: Nominal electrode zero and slope user-defined Com- Response Unit Description mand RPCA0NZ ± xx.xx [pH] Nomminal zero RPCA0NS ± xxxxE–3 [V/pH] Nominal slope RPCA0U ±...
  • Page 45 WPAINA Assignment of recorder output Temperature Input for printer control WPCASA Calibration buffer set Knick techn. buffers Mettler Toledo technical buffers Merck Titrisol buffers Techn. buffers to DIN 19 276 Standard buffers to DIN 19 266 Merck Titrisol buffers...
  • Page 46 765 Laboratory pH Meter Only for meters with Option 346: Nominal electrode zero and slope are set as fol- lows: Command Parameter Unit Description WPCA0NZ Num. par. [pH] Nominal zero point WPCA0NS Num. par. [V/pH] Nominal slope WPCA0U Num. par.
  • Page 47: Troubleshooting

    3 Troubleshooting Error messages Range exceeded If a measured value is out of range, an error mes- sage is displayed instead of the value measured. The measured pH value is < –2 or > +16. Possible causes: • Electrode defective •...
  • Page 48 765 Laboratory pH Meter Calibration error messages When errors occur during calibration or when the determined electrode data are out of range, an error message will be displayed. The meter cannot identify the buffer solution in use. This message is only momentarily displayed during calibration.
  • Page 49 The electrode zero determined during calibration is out of range. Electrode zero is < pH 6 or > pH 8 (for Option 346: at ± 1 pH unit from nominal zero) This message is displayed in measuring mode after a calibration. It can only be reset by a new calibra- tion.
  • Page 50 765 Laboratory pH Meter Interface error message When errors occur during transmission via inter- face, an error message is displayed. The meter has received an invalid interface com- mand. Possible causes: • Syntax error in interface command • Too many characters in one string •...
  • Page 51: Appendix

    ZU 6956 power pack Power pack for immersion stirrer ZU 6956 Lab Printer ZU 0244 Interface cable for connecting the Model 765 ZU 0245 to a printer (ZU 0244) Interface cable for connecting the Model 765 ZU 0152 to a computer (special EMC cable)
  • Page 52: Specifications

    765 Laboratory pH Meter Specifications Ranges –2.00 to +16.00 –1999 to +1999 °C: –50.0 to +150.0 Display Alphanumeric, 2 x 4 digits, 14-segment LED, Character height 13 mm Parameters: pH/mV/°C/time 3 status indicators for electrode con- dition Measuring cycle Approx. 1/sec <...
  • Page 53 Electrode condition displayed as good/average/poor, can be disabled ® Knick Drycheck Monitors electrode impedance for dry-out, glass breakage and defec- tive connections, also in standby mode Calibration timer monitors a preset calibration interval ®...
  • Page 54 765 Laboratory pH Meter Remote interface RS 232 without control lines, galvani- cally isolated, user defined as printer or computer interface Baud rate: 600/1200/2400/4800/ 9600 Data formats: 7 bits even/odd 8 bits without parity Protocol: None, XON/XOFF Stop bits: Isolation...
  • Page 55: Buffer Tables

    IP 54 protection, ready for connection of ZU 6954 attachment stand Dimensions 244 x 95 x 255 mm (w x h x d) Weight Approx. 2 kg Buffer tables Buffer set 00 Knick technical buffers °C 2.03 4.01 7.12 9.52 2.02 4.01 7.09 9.45...
  • Page 56 765 Laboratory pH Meter Buffer set 01 Mettler-Toledo technical buffers (correspond to Ingold technical buffers) °C 2.03 4.01 7.12 9.52 2.02 4.01 7.09 9.45 2.01 4.00 7.06 9.38 2.00 4.00 7.04 9.32 2.00 4.00 7.02 9.26 2.00 4.01 7.00 9.21 1.99...
  • Page 57 Buffer set 03 Technical buffer solutions to DIN 19 267 °C 1.08 3.14* 4.67 6.89 9.48 13.95* 1.08 3.12* 4.67 6.87 9.43 13.63* 1.09 3.10 4.66 6.84 9.37 13.37 1.09 3.08 4.66 6.82 9.32 13.16 1.09 3.07 4.65 6.80 9.27 12.96 1.09 3.06...
  • Page 58 765 Laboratory pH Meter Buffer set 05 Merck Titrisol buffers and ready-to-use buffer solutions, Riedel Fixanal buffers and ready-to-use buffer solutions °C 0.96 3.05 6.04 8.15 10.26 13.80 0.99 3.05 6.02 8.10 10.17 13.59 0.99 3.03 6.01 8.07 10.11 13.37 0.99...
  • Page 59 Buffer set 07 Ciba (94) Nominal value: 2.06, 4.00, 7.00, 10.00 °C 2.04 4.00 7.10 10.30 2.09 4.02 7.08 10.21 2.07 4.00 7.05 10.14 2.08 4.00 7.02 10.06 2.09 4.01 6.98 9.99 2.08 4.02 6.98 9.95 2.06 4.00 6.96 9.89 2.06 4.01 6.95...
  • Page 60 765 Laboratory pH Meter Appendix...
  • Page 61: Glossary

    Glossary Buffer set Contains selected buffer solutions which can be used for automatic calibration with the Knick Cali- ® matic . The buffer set must be selected prior to the first calibration. Buffer solution Solution with an exactly defined pH value for cali- brating a pH meter.
  • Page 62 765 Laboratory pH Meter ® Diagnostics record Printout of criteria for Sensoface display, all rele- vant electrode data, electrode statistics and results ® of Fullcheck device self test for documentation to GLP. Start printout by pressing Electrode slope Specified in mV/pH. It is different for each electrode and changes with age and wear.
  • Page 63 Nominal electrode Nominal value of electrode zero point. For commer- zero point cial electrodes, the nominal electrode zero point is at pH 7. Special electrodes can have a different zero point. If you want to use such an electrode, your meter must be equipped with Option 346.
  • Page 64 765 Laboratory pH Meter ® ® Sensoface Automatic electrode monitoring. The Sensoface display provides information on the electrode con- dition. It evaluates zero point, slope, response time, impedance and dry-out of the electrode and the cal timer count. Slope See Electrode slope.
  • Page 65: Index

    Device self-test 27 Operation Diagnostics Meter design 2 Diagnostics level 21 Option 346 13 Electrode Data menu 21 Knick Fullcheck menu 21 Sensoface menu 21, 22 Package contents 1 Diagnostics record 29 Parameter record 12 Displaymatic 13 Parameter setting Double platinum electrode 7...
  • Page 66 Parameters 31 Short check (at power-on) 8 Pin assignment 31 Short description 1 Printer 32 Specifications 46 RS 232 interface 31 Standby mode 8 Safety information III Trueline recorder output 30 Sensoface 5 Two-point calibration 19 Sensoface menu 21, 22 Sensor monitoring 5 Setting VIEW menu 10...

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