Conductivity Monitor CM-P User Manual
Contents
1. 29 9 5 Operation 5 Operation 5 1 Setting the H t with buffer A Press 1 second 100 Press 1 second Fig 4 Setting the scale When the conductivity monitor is switched on it is in Run Mode and will display the measured conductivity To set the output range to the recorder the conductivity levels 100 and 0 can easily be set with the high and low conductivity buffers used for the gradient 1 Start the flow in the system with the high conductivity buffer we A set 2 When the conductivity reading stabilises esf for 1 second 3 Change to the low conductivity buffer and when the new conductivity level is set stable ws for 1 second The monitor is now ready for use The setting of the 10096 and 096 levels will remain in the transmitter until a new scale is set 10 Conductivity Monitor CM P User Manual 18 1101 29 5 Operation 5 2 Menu Set 100 Fig 5 Menu overview With the menu key more advanced functions can be programmed such as setting the conductivity to any range independent of the buffers and temperature compensation of the conductivity to reference temperature The menu key is also used to step between the functions Conductivity Monitor CM P User Manual 18 1101 29 11 5 Operation 5 3 Fixed scale setting 12 Set 100 125 mS Exits to Run Mode Fig 6 Fixed scale setting The 100 and 0 conductivity values can be s2. through or injected into the flow cell The voltage output to the recorderis set to 0 V for the measured conductivity id This key sets the 100 conductivity level with the high conductivity buffer The set 10096 key is pressed for 1 second while the high conductivity buffer is pumped through or injected into the flow cell The voltage output to the recorder is set to 1 V for the measured conductivity The menu is used to step between the functions below 1 Set 100 With this function any fixed conductivity value in mS cm can be set for the 100 level 2 Set 0 With this function any fixed conductivity value in mS cm can be set for the 0 value Conductivity Monitor CM P User Manual 18 1101 29 5 2 General description 2 3 Flow cell Y l Mode Set TC A temperature compensation factor for the conductivity can be set This can be necessary for high precision measurements The temperature compensation factor is expressed in percentage increase of conductivity per C increase in temerature If the temperature compensation factor is unknown a general approximate value for many common salt buffers used in chromatography applications When the temperature compensation is set to 0 it is inactive Set TRcf The temperature compensation factor must be realted to and adjusted to a set reference temperature in range 4 40 C The arrow down and arrow up keys are used to select numerical values in the menu setting
3. Conductivity Monitor CM P Conductivity transmitter CM P lt User Manual 18 1101 29 Edition AC Amersham e Biosciences Conductivity Monitor CM P User Manual 18 1101 29 Contents T Introduction eiie rh rr et ir casei save denna cess eren Nerea ead ate reee NTE EE AE EEEa 2 General Descriptlon 3 4 ertet eee ES EERE Re EEEE ENEA E MER Hoe SER gens ke tu dv 2 1 Principle of operation ccecccssseessecessecessceeeeeceeeecesseeeeeeeeeecceaeeceseeeeaeeesseeeees 2 2 TRANSMIT yes eee eee Rene EHE EE Rene HEY EE Ree e E YXTHE ER e ee ER Ee ER Eee ee E GRAS 2 2 Front Panel uccide eret tri eee e exirent reete uda Nar eee exter vie pde 3 Technical Specifications ccccesscesscesseccesseceseeeeeecceaceceaeeeeseeceseeceseeeeeeceeaeeenaeeeeeeees A InstalldtlOm ceca osito sie i vereri e e er eeu bte eru p e asennad eue eR i Ee 4 1 Connection of the flow cell ttr ene toe retorno 4 2 Transmitter set Up nce gite XE PEREAT EX AE Cree in name 3 Operation stole eatem a P o a a Oe eer D RE RO Feeds 5 1 Setting the scale with buffers sisser ia anie e Fees pe tap ts 5 3 Fixed scale Setting ereenn e ae EE e EE EN eir aee ree Ea gres Ga as 3 4 Temperature compernsatlOm 1 iet pe Eri Bha o Pie EE P eee e ERE eee 5 5 Summary of commands in menu sese eene eene G Maintenance Ee E 6 1 Cleaning the flow cell 1 1 eet tnter tree trier pee E ern 6 2 Calibration Mode ied tree tt
4. Through this communication the conductivity measurement is transmitted to UNICORN The electrical outputs are only used for a possible optional recorder The monitor has a very large dynamic range from 0 001 mS cm to 999 9 mS cm and therefore suitable for a wide range of applications ranging from reversed phase to hydrophobic interaction chromatography A unique design of the electronics is the microprocessor control of frequency variations within the working range This gives excellent linetary and eliminates the need for range settings Conductivity Monitor CM P User Manual 18 1101 29 3 2 General description 2 1 Principle of operation 2 General description Fig 1 The flow cell The flow cell has two cylindrical shaped titanium electrodes positioned in the flow path of the cell An alternating voltage is applied between the electrodes and the resulting current is measured and used to calculate the conductivity of the eluent The microprocessor controls the AC frequency and automatically increases it with increasing conductivity between 50 Hz and 50 kHz This unique design gives maxi mum lineatary and true conductivity values The monitor measures conductivity over the complete working range No range settings are required However to obtain a suitable output signal to the recorder and to get a relative conductivity value it is possible to set a O to 100 range This can be done with the buffers used or by selecti
5. crease in percentage per C can be used for most common salts used in liquid chromatography applications When the temperature compensation is set to 0 this function is inactive Conductivity Monitor CM P User Manual 18 1101 29 13 5 Operation 14 In the example below the temperature compensation factor is changed from a previosly set value of 2 1 to a new value of 2 0 The reference temperture is change from 23 5 C to 25 0 C 1 Press three times until the Set TC menu is displayed 2 Set the value of the temperature compensation factor to 2 0 using the A 3 Press d keys e 5 ej to accept the value Set to 2 096 is displayed 4 Press to set the temperature to which the conductivity values should be corrected Tref 23 5 C is displayed Use the ra and d keys to set the temperature to 25 0 C 5 Press to accept the temperature 6 Press again to exit to Run Mode Conductivity Monitor CM P User Manual 18 1101 29 5 Operation 5 5 Summary of commands in menu Set 100 tt 125 mS s Set TC E Set to 21 p 2 0 Set Tref faa Set to 23 5 C 25 0 C oot ES Exits to Run Mode Exits to Run Mode Exits to Run Mode Exits to Run Mode Fig 8 Summary of commands Conductivity Monitor CM P User Manual 18 1101 29 15 6 Maintenance 6 1 Cleaning the flow cell 6 2 Calibration Mode 16 6 Maintenance The Conductivity Monitor req
6. e temperature compensation factor to O None required Use a flow restrictor after the conductivity monitor flow cell Check for loose tubing connections Clean flow cell according to procedure described in section 6 1 Use temperature compensation factor Call a Amersham Biosciences service representative Conductivity Monitor CM P User Manual 18 1101 29 8 Accessories 8 Accessories Designation Code No Conductivity Flow Cell 19 1515 15 Trademarks Amersham and Amersham Biosciences are trademarks of Amersham plc Amersham Biosciences AB 2000 All rights reserved All goods and services are sold subject to the terms and conditions of sale of the company within the Amersham Biosciences group which supplies them A copy of these terms and conditions is available on request Amersham Biosciences AB Bj rkgatan 30 SE 751 84 Uppsala Sweden Amersham Biosciences UK Limited Amersham Place Little Chalfont Buckinghamshire HP7 9NA England Amersham Biosciences Inc 800 Centennial Avenue P O Box 1327 Piscataway New Jersey 08855 USA Amersham Biosciences Europe GmbH Postfach 5480 D 79021 Freiburg Germany Conductivity Monitor CM P User Manual 18 1101 29 23 goog av eiresddp YL Aq uepewg ul paud 2 Amersham e Biosciences Conductivity Monitor CM P User Manual 18 1101 29
7. ept the value 4 Press again to exit to Run Mode Conductivity Monitor CM P User Manual 18 1101 29 6 Maintenance 6 6 Summary of commands in Calibration Mode Warning Exits to Run Mode Set to Exits to 86 60 mS Run Mode Exits to Run Mode Constant Set to 41 0 cm 43 0 cm Exits to Run Mode Fig 14 Summary of commands Conductivity Monitor CM P User Manual 18 1101 29 21 7 Trouble Shooting 22 7 Trouble Shooting Problem Possible cause Remedy Baseline drift or noisy signal monitor described in The absolute conductivity value is wrong Ghost peaks appear in the gradient profile Conductivity measurements with the same buffer appear to The monitor does not respond to conductivity change Air in flow cell Dirty flow cell Column not equilibrated or dirty The electrical grounding of the electrode is influenced by another instrument Temperature compensation is on Charged sample detected e g protein Air bubbles passing through flow cell Dirty flow cell Room temperature has decreased Faulty flow cell or transmitter Use a flow restrictor after the conductivity flow cell Check for leaking tubing connections Clean flow cell according to procedure Maintenance 6 1 Equilibrate and or regenerate column Turn the flow cell so the end with the screws is electrode is influenced by facing the other instrument Set th
8. et to any value of your choice e g to extend the recorder full scale deflection and baseline to be slightly over and under the conductivity of the buffers In addition it might be easier to read the conductivity values for specific peaks in a chromatogram if the scale is in tens or hundred of mS cm In this example the conductivity scale is changed from a previously set 100 value of 125 mS cm to a new value of 150 mS cm the 0 value is changed from 3 5 mS cm to 0 00 mS 1 Press the previously set 100 value is displayed 2 Use E and He to set the conductivity value to 150 mS 3 Press to accept the value Set to 150 mS is displayed 4 Press again to set the 0 value 5 Set the value for 0 to 0 00 mS using the LC Jon M 6 Press to accept the setting Set to 0 mS is displayed 7 Press again to exit Run Mode Conductivity Monitor CM P User Manual 18 1101 29 5 Operation 5 4 Temperature compensation Set 100 125 mS Exits to Run Mode Fig 7 Temperature compensation setting Temperature variations may influence conductivity If high accuracy in the specific conductivity is required a temperature compenstion factor can be programmed togheter with a reference temperature All conductivity values will then automatically be converted to the set reference temperature If the temperature coefficient is unknown a recommended average temperature compenstion factor of 2 conductivity in
9. ng any fixed range between 0 001 mS cm and 999 9 mS cm The monitor displays the conductivity in mS The conductivity is automatically calculated by multiplaying the measured conductance by the flow cells cell constant The cell constant is pre calibrated on delivery but can be measured with a separate calibration procedure One of the electrodes has a small temperature sensor for measuring the temperature of the eluent in the flow path Temperature variations influence the conductivity and in some applications when highly precise conductivity values are required it is possilble to program a temperature compensation factor that recalucates the conductivity to a set reference temperature Conductivity Monitor CM P User Manual 18 1101 29 2 General description 2 2 Transmitter The microprocessor based transmitter communicates with the UNICORN controller over a serial interface using the optomux communication protocol The transmitter fits into a 19 industry standard rack 2 1 1 Front panel The front panel consists of an alphanumerical LCD display window and a keyboard with six membrane keys Conductivity transmitter Fig 2 The front panel Display mS Displays the actual conductivity value in mS mS cm and the relative conductivity in 96 Keyboard This key sets the 0 conductivity level eith the low coductivity buffer The set 0 keys is pressed for 1 second while the low conductivity buffer is pumped
10. s The keys can be held down for a faster scroll d The enter key is used to enter programmed values and to exit to Run The flow cell exterior is made of PEEK and the interior between the titanium electrodes of flouroplastics Both ends of the flow cell have female M6 fittings The signal cable which connects to the control unit has a 9 pole DSUB connector Coi ductivity Monitor CM P User Manual 18 1101 29 3 Technical Specifications 3 Technical Specifications Operating mode Sensitivity range Accuracy Noise Flow rate range Analogue output Power supply Operating conditions Power consumption Flow cell Type Cell constant Internal volume Maximum operating pressure Wetted parts Fittings Auto range conductivity in mS cm 0 001 mS cm 999 9 mS cm 2 full scale calibrated range or 0 01 mS cm whichever is greater in the range 0 001 300 mS cm 0 5 full scale calibrated range 0 100 ml min 0 1 V or 4 20 mA 24V DC 4 40 C 20 95 RH Atmospheric pressure 840 1060 mb 84 106 kPa 2W Flow through 50 cm nominal 14 Ill 5 MPa 50 bar 750 psi Fluoroplastics titanium M 6 6 mm metric Conductivity Monitor CM P User Manual 18 1101 29 7 4 Installation 4 Installation 4 1 Connection of the flow cell Fig 3 Connection of flow cell to UNICORN control box 1 Connect the signal cable from the cell to the socket Cond on the UNICORN Control box 4 2 Transm itter The transmitter i
11. s correctly set up on delivery of the system Set up parameters are saved in non volatile memory and do not need to be changed Make a note of the optomux communication parameters for your transmitter If a faulty transmitter is replaced with a new unit the optomux parameters for the new unit should be set to the same values as for the old transmitter To set parameters start the monitor in start up mode by pressing and simultaneosly as the power is switched on and keeping the buttons pressed for about 5 seconds The display is dark for 5 seconds then shows the program version for 5 seconds followed by the current optomux address e g Optomux addr 002 The addres is a number between 0 and 255 Refer to your system documetation for the correct address Press the arrow keys to change the address until the correct value is displayed then press enter The display now shows the communication rate e g Baudrate 38400 Permissible baud rates are 1200 2400 4800 9600 19200 and 38400 Normally 38 400 is used the correct setting is determinded by the optopux 8 Conductivity Monitor CM P User Manual 18 1101 29 4 Installation communication port setting in the controller Use the arrow keys to choose the correct communication baud rate then press enter The display now shows the accumulated operation time and the number of starts e g 00021 h 0003 st Press enter to continue Conductivity Monitor CM P User Manual 18 1101
12. se the ra and d keys to set the temperature on the control unit to 25 0 C the temperature shown on the thermometer 5 Press to accept the setting 6 Press again to exit the Calibration Mode Conductivity Monitor CM P User Manual 18 1101 29 17 6 Maintenance 6 4 Calibration of the cell constant 18 Warning 2 Set to 86 60 mS Constant 43 2 cm Exits to Run Mode Fig 11 Calibration of cell constant Normally it is not necessary to calibrate the flow cell as it is pre calibrated on deli very Calibration of the flow cell is only necessary when the monitor is to be used to determine specific conductivity with high accuracy In the example below the cell constant is changed by setting the conductivity value of a calibration buffer to theoretical value at an exact temperature 1 Prepare a calibration solution of 1 00 M NaCl 58 44 g l 2 Fill the flow cell with the calibration solution either via a syringe or by pumping at least 15 ml through the cell 3 Stop the flow and wait for 15 minutes until the temperature is constant in the range 20 30 C 4 Read the conductivity value displayed Note Make sure the Temperature Compensation is off 5 Press and simultaneously for 2 seconds to enter the Calibration Mode 6 Read the temperature in the Adj temp menu Compare the erlier displayed conductivity value with the theoretical value from the graph below at the tempera
13. ti ee vete er ee teer eA FER res aea 6 3 Calibration of the temperature sensor sess 6 4 Calibration of the cell constant sees 6 5 Replacing the flow cell eeesssessseeeseeeeeeee eene nene enne 20 6 6 Summary of commarnds in Calibration Mode sese 21 7 Trouble Shooting sen tette estie hes ee ota ea eaa E NNa ENERE EEEE 22 9 NCCeSSOTIOS kinansa ae on edes ev ves Pede be io rdi e d a Voc Peu Edi Here sey ESL Seve ve EE va EEEN raus 23 Conductivity Monitor CM P User Manual 18 1101 29 Conductivity Monitor CM P User Manual 18 1101 29 1 Introduction 1 Introduction The Amersham Biosciences Conductivity Monitor CM P is a high quality high precision on line monitor for conductivity measurements and gradient determination in liquid chromatography applications The monitor consist of two units the flow cell and the transmitter The flow cell contains the titanium electrodes used for conductivity measurement as well as a temperature sensor The small size of the flow call allows it to be posiotioned anywhere in the liquid path provided that the pressure specification for the cell is not exceeded The transmitter carries the six programming keys for the monitor An easy to read 16 digit alphanumeric display shows the conductivity measured in Siemens cm mS cm The transmitter communicates with the UNICORN controller over a serial interface using optomux protocol
14. ture of the calibration solution If the theoretical and the displayed value correspond no further action is required If the values duffer proceed as outlined below Conductivity Monitor CM P User Manual 18 1101 29 6 Maintenance 7 Press again until the display shows adjust cond Use the ra anal S keys to enter the theoretical value 8 Press to accept the value The new cell constant is automatically calculated 9 Press again and the new cell constant value will be displayed in the me Constant Note Do not change this value 10 Press to exit to run mode 97 95 we z m E EE iui P 80 77 Temperature C Fig 12 Conductivity of 1 M NaCl at 20 30 C Conductivity Monitor CM P User Manual 18 1101 29 19 6 Maintenance 6 5 Replacing the flow cell 20 AA Shown for 2 s Adj temp Adj cond EH Constant Set to 43 0 cm 41 0 cm Exits to Run Mode Fig 13 Changing the cell constant If the flow cell is replaced with a new flow cell the monitor must be calibrated with the new cell constant value The new cell constant is written on the package In the example below the cell constant is changed from 43 0 cm to 41 0 cm 1 Press and simultaneously for 2 seconds to enter the Calibration Mode 2 Press twice until Constant 43 0 cm is shown in the display Use the ra and d keys to set the cell constant to 41 0 cm 3 Press to acc
15. uires very little maintenance if precautions are taken to protect the flow cell Note When the flow cell is not in use rinse the cell with de ionised water do not leave buffers to dry in the cell When the monitor is stored for a longer period of time fill it with 20 ethanol The flow cell is designed to withstand cleaning in place with 1 M NaOH Warning Fig 9 Calibration Mode menu Conductivity Monitor CM P User Manual 18 1101 29 6 Maintenance 6 3 Calibration of the tem perature sensor Warning o3sec L Exits to Run Mode Adj temp Fig 10 Calibration of the temperature sensor The cell constant and the temperature sensor can be calibrated in the monitor calibration mode New monitors are factory calibrated and it is not recommended to change these values Calibration of the temperature sensor is only necessary if the monitor is used to determine absolute conductivity with high accurary In the example below the temperature is adjusted from 23 5 C to the measured temperature of 25 0 C 1 Place the flow cell together with a precision thermometer inside a box or beaker to ensure that they are not exposed to draft Leave them for 15 minutes to let the temperature stabilise 2 Read the temperature on the thermometer 3 Press and simultaneosly for 2 seconds to enter the Calibration Mode 4 The display shows Adjust temp 23 5 C U
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