Metrohm 884 Professional VA Manual - Short Instructions Download Page 58

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3.3 Equipping the RDE measuring head

￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭

￭￭￭￭￭￭￭￭

884 Professional VA

Figure 34

Connecting the gas inlet

3.3.2

Preparing electrodes and inserting them in the RDE measuring
head

The 884 Professional VA uses the potentiostatic three-electrode principle.
The following electrodes are used:

￭

Rotating disk electrode (RDE) as working electrode (WE)

￭

Reference electrode (RE)

￭

Auxiliary electrode (AE)

NOTE

Please also observe the notes contained in the electrode leaflets sup-
plied with the electrodes. In addition, you can learn how to best handle
the electrodes from the multimedia guide (A.717.0002).

NOTE

If you are using the instrument for voltammetric applications, the gas
inlet has to be connected beforehand

(see Chapter 3.3.1, page 48)

. If

the instrument is only going to be used for CVS applications, the gas
inlet does not have to be connected.

Summary of Contents for 884 Professional VA

Page 1: ...884 Professional VA Manual Short Instructions 8 884 8002EN 2017 06 30 ...

Page 2: ......

Page 3: ...Metrohm AG CH 9100 Herisau Switzerland Phone 41 71 353 85 85 Fax 41 71 353 89 01 info metrohm com www metrohm com 884 Professional VA Manual Short Instructions 8 884 8002EN 2017 06 30 mb ...

Page 4: ...techcom metrohm com This documentation is protected by copyright All rights reserved This documentation has been prepared with great care However errors can never be entirely ruled out Please send comments regarding possible errors to the address above ...

Page 5: ...6 7 Recycling and disposal 9 2 Overview of the instrument 10 2 1 Front 10 2 2 Rear 11 2 3 MME measuring head 13 2 3 1 MME measuring head overview 13 2 3 2 Measuring head connector plate and measuring head insert 14 2 3 3 Tubing connector measuring head arm 17 2 4 RDE measuring head 19 2 4 1 RDE measuring head overview 19 2 4 2 Measuring head connector plate and measuring head insert 20 2 4 3 Tubin...

Page 6: ...ng instruments electrically 58 3 4 1 Connecting the instrument to the power grid 58 3 4 2 Connecting the 884 Professional VA 58 4 Start up 61 5 Operation and maintenance 64 5 1 Replacing the measuring head 64 5 2 Performing a Dummy cell test 67 6 Troubleshooting 69 6 1 List of faults 69 6 1 1 General problems 69 6 1 2 884 Professional VA for VA trace analysis 70 6 1 3 884 Professional VA for CVS 7...

Page 7: ...l 37 Figure 21 Connecting a reference electrode 38 Figure 22 Structure of the auxiliary electrodes 39 Figure 23 Connecting the auxiliary electrode 41 Figure 24 Do not touch the drive disk 42 Figure 25 Inserting the measuring head 42 Figure 26 Gas washing glass 43 Figure 27 Installing the measuring head cover 44 Figure 28 Inserting the stopper in the pipetting opening 45 Figure 29 Do not touch the ...

Page 8: ......

Page 9: ...nt Together with the viva computer software it forms a measurement system specially designed for VA trace analysis with the MME measuring head and the CVS determination of additives in gal vanic baths with the RDE measuring head In combination with an MME measuring head the instrument makes it possible to verify or quantita tively determine materials in low concentrations using voltammetry polar o...

Page 10: ...you can automate the addition of reagents and auxiliary solutions by using dosing devices of the type 800 Dosino The 884 Professional VA instrument must be started operated and con trolled via the viva computer software The data transfer between the measuring instrument and the PC takes place via a USB connection At the end of every determination the data voltammogram results etc is saved in a dat...

Page 11: ...sis of electroplating baths for the quantitative determination of organic additives The main fields of applica tion are the following electroplating bath types Acidic copper baths Tin baths Tin lead baths Alkaline zinc baths Nickel baths This instrument is suitable for processing various chemicals and flammable samples Therefore the use of the 884 Professional VA requires the user to have basic kn...

Page 12: ...ent displayed in the figures also applies the same to the other measuring head 1 5 2 Further information and literature You can find further information regarding the 884 Professional VA in the following publications CVS tutorial 8 103 8010XX VA tutorial 8 103 8033XX Electrodes in Voltammetry multimedia guide A 717 0002 Online help for the viva computer software Voltammetric analysis methods in el...

Page 13: ...on to a possible biological hazard CAUTION This symbol draws attention to possible damage to instruments or instrument parts NOTE This symbol highlights additional information and tips 1 6 Safety instructions 1 6 1 General notes on safety WARNING This instrument may only be operated in accordance with the specifica tions in this documentation This instrument has left the factory in a flawless stat...

Page 14: ... The electrical safety when working with the instrument is ensured as part of the international standard IEC 61010 WARNING Only personnel qualified by Metrohm are authorized to carry out service work on electronic components WARNING Never open the housing of the instrument The instrument could be damaged by this There is also a risk of serious injury if live components are touched There are no par...

Page 15: ...e you set up or disconnect electrical plug connections at the rear of the instrument 1 6 4 Personnel safety WARNING Handling hazardous substances Hazardous substances may result in injuries Wear protective glasses and work clothes suitable for laboratory work WARNING Uncontrolled splashing of reagents Splashing reagents may result in injuries Operate the 884 Professional VA only with the measuring...

Page 16: ...r work involving mercury well ventilated Use amalgamation to bind any spilled mercury Never use a broom or vacuum Only have mercury disposed of by a professional Never dispose of mercury in household or domestic waste NOTE For detailed information observe the Mercury Handling Guidelines 8 000 5054XX 1 6 6 Tubing and capillary connections CAUTION Leaks in tubing and capillary connections are a safe...

Page 17: ...prevent negative effects on the environment and public health More details about the disposal of your old instrument can be obtained from your local authorities from waste disposal companies or from your local dealer The MME pro Multi Mode Electrode pro contains toxic mercury never dispose of it in domestic waste For more information on the recycling and disposing of mercury observe the Mercury Ha...

Page 18: ... 884 Professional VA front 1 Status LED Continuously on instrument ready for oper ation Blinking regularly instrument operat ing Blinking pattern LED on a long time off a short time on a long time off a short time etc Standby potential is being applied to the electrodes Do not remove the electrode cables 2 On LED Illuminated if the 884 Professional VA is con nected to the power supply ...

Page 19: ...glass 6 2405 030 For wetting the inert gas 7 Decanting glass 6 2405 030 For the deposition of solid materials that may be present such as electrode mercury in fully automated mode 8 Holder for drip pan For positioning the drip pan 2 2 Rear 1 2 3 4 5 6 7 8 9 Figure 2 884 Professional VA rear 1 Temperature sensor connector Temp For connecting a temperature sensor of the type Pt1000 Two B sockets 2 m...

Page 20: ... arm See Chapter 2 3 3 Page 17 6 USB connectors USB 1 and USB 2 type A For connecting barcode readers keyboards etc 7 Controller connector For connecting to a PC with the viva com puter software installed Mini DIN 8 pin 8 MSB connectors MSB 1 to 4 Metrohm Serial Bus For connecting dosing devices 800 Dosino and Remote Boxes Mini DIN 8 pin 9 Power socket ...

Page 21: ...re 3 MME measuring head Overview 1 Measuring head insert With openings for inserting electrodes and tubing connections see Figure 5 page 16 2 Measuring head connector plate For connecting the MME measuring head to the connector plate of the measuring head arm 1 4 For connecting the electrodes and tubing see Figure 4 page 14 ...

Page 22: ...r plate 1 M6 threaded opening 3 For adding or aspirating solutions Can be connected to one of the openings 24 27 FEP tubing from 6 1829 070 2 M6 threaded opening 2 For adding or aspirating solutions Can be connected to one of the openings 24 27 FEP tubing from 6 1829 070 3 M6 threaded opening N2 For connecting the inert gas supply N2 Connected directly to the working electrode The tubing comes pre...

Page 23: ...ectrode cables for connecting elec trodes 8 Threaded opening PURGE For tubing connection to opening 19 gas inlet in the measuring solution 9 Flexible drive shaft for the stirrer 10 M6 threaded opening N2 For connecting the inert gas supply N2 Connected directly to the working electrode The tubing comes pre installed 11 M6 threaded opening OUT With preinstalled tubing connection to opening 18 gas o...

Page 24: ...the stirrer 16 Threaded opening With preinstalled screw nipple and stopper Can be equipped with a four way micro dos ing tip 6 1824 000 17 M6 threaded opening With preinstalled tubing connection to threaded opening 12 TAP gas inlet to the tapping mechanism 18 Opening With preinstalled tubing connection to threaded opening 11 OUT gas outlet 19 Opening For tubing connection to threaded opening 8 PUR...

Page 25: ...1 2 3 or WASTE FEP tubing from 6 1829 070 27 Opening For adding or aspirating solutions Can be connected with threaded opening 1 2 3 or WASTE FEP tubing from 6 1829 070 28 Opening For the automatic sample addition Must be connected to threaded opening 5 SMP PEEK capillary 6 1831 020 29 Opening for sensor For inserting a temperature sensor Pt1000 30 Opening For feeding through the temperature senso...

Page 26: ... 5 M6 threaded opening 1 For connecting tubing for aspirating or add ing solutions 6 M6 threaded opening WASTE For connecting tubing for aspirating the measuring solution 7 M6 threaded opening OUT For pressure compensation in the measuring vessel ...

Page 27: ...re 7 RDE measuring head Overview 1 Measuring head insert With openings for inserting electrodes and tubing connections see Figure 9 page 22 2 Measuring head connector plate For connecting the RDE measuring head to the connector plate of the measuring head arm 1 4 For connecting the electrodes and tubing see Figure 8 page 20 ...

Page 28: ...re 8 Measuring head connector plate 1 M6 threaded opening 3 For adding or aspirating solutions Can be connected to one of the openings 24 27 FEP tubing from 6 1829 070 2 M6 threaded opening 2 For adding or aspirating solutions Can be connected to one of the openings 24 27 FEP tubing from 6 1829 070 3 M6 threaded opening N2 With preinstalled stopper Not applicable to RDE applications 4 M6 threaded ...

Page 29: ...uring solution For voltam metric applications not applicable to CVS analyses 9 Drive shaft for rotating disk electrode RDE 10 M6 threaded opening N2 With preinstalled stopper Not applicable to RDE applications 11 M6 threaded opening OUT With preinstalled tubing connection to opening 18 gas outlet For voltammetric applications not applicable to CVS analy ses 12 M6 threaded opening TAP With preinsta...

Page 30: ...ith a four way micro dos ing tip 6 1824 000 17 M6 threaded opening With preinstalled tubing connection to threaded opening 12 TAP gas inlet to the tapping mechanism For voltammetric appli cations not applicable to CVS analyses 18 Opening With preinstalled tubing connection to the threaded opening 11 OUT gas outlet For voltammetric applications not applicable to CVS analyses 19 Opening For tubing c...

Page 31: ...or adding or aspirating solutions Can be connected with threaded opening 1 2 3 or WASTE FEP tubing from 6 1829 070 27 Opening For adding or aspirating solutions Can be connected with threaded opening 1 2 3 or WASTE FEP tubing from 6 1829 070 28 Opening For the automated sample addition Must be connected to threaded opening 5 SMP PEEK capillary 6 1831 020 29 Opening for sensor For inserting a tempe...

Page 32: ... 32 threaded opening SMP For connecting a PEEK capillary for the auto mated sample addition 5 M6 threaded opening 1 For connecting tubing for aspirating or add ing solutions 6 M6 threaded opening WASTE For connecting tubing for aspirating the measuring solution 7 M6 threaded opening OUT For pressure compensation in the measuring vessel ...

Page 33: ...e of vibrations and which provides protection against corrosive atmosphere and contamination by chemicals The instrument should be protected against excessive temperature fluctua tions and direct sunlight Do not place the instrument in the vicinity of an air conditioning unit outlet 3 2 Equipping the MME measuring head The openings and connections on the measuring head of the 884 Profes sional VA ...

Page 34: ...to be removed first Proceed as follows to do this 1 Remove the stopper 3 5 from the pipetting opening Figure 11 Removing the stopper from the pipetting opening 2 Pull the slide lock 3 4 on the top of the measuring head cover towards you and at the same time tilt the measuring head cover to an angle of approx 45 and remove it 1 2 Figure 12 Removing the measuring head cover ...

Page 35: ...suring head arm again CAUTION The measuring head insert see Figure 5 page 16 is made of PTFE Do not use sharp objects around it to ensure the material is not damaged 3 2 1 Preparing the MME measuring head 1 Connecting the gas inlet Insert the PTFE tubing for adding gas to the solution 6 1829 030 through the opening 5 19 Pull the transparent inner tubing through as far as it will go Ensure that the...

Page 36: ...E measuring head 28 884 Professional VA Figure 13 Inserting the gas inlet Connect the tubing to the PURGE threaded opening 4 8 and tighten it handtight Finally tighten the tubing nipple using the wrench provided 6 2739 000 ...

Page 37: ...ile fastening the flexible shaft push it through as far as it will go Tighten the flexible shaft To do so screw the clamping screw for the flexible shaft into the stirrer using two wrenches 6 2739 000 In the process ensure that the flexible shaft is not bent Figure 15 Screwing in the flexible shaft Insert the stirrer into the opening 5 15 and press it down as far as it will go ...

Page 38: ...the flexible shaft through so that it creates a smooth curve The flexible shaft may be damaged or become unusable if a kink forms or the flexi ble shaft is put under tension Screw the clamping screw for the flexible shaft to the drive shaft using two wrenches 6 2739 000 In the process ensure that the flexible shaft is not kinked Figure 16 Inserting and connecting the stirrer ...

Page 39: ...lue in the figure have a smaller diam eter than the others Keep this in mind when inserting the stop pers Figure 17 Inserting stoppers 3 2 2 Preparing electrodes and inserting them in the MME measuring head The 884 Professional VA uses the three electrode principle The following electrodes are used Multi Mode Electrode pro MME pro as the working electrode WE Reference electrode RE Auxiliary electr...

Page 40: ...de WE Preparing and inserting the working electrode Proceed as follows 1 Preparing the working electrode Prepare the working electrode in accordance with the instructions in the Multi Mode Electrode pro document 8 110 8018XX In prepa ration carry out the following tasks Mount the capillary Insert the needle Topping up the mercury 2 Inserting the working electrode into the measuring head insert Pla...

Page 41: ...TION The electrode cables for the reference working and auxiliary elec trode are identical Observe the markings on the plugs because the three cables must not be mixed up Plug the electrode cable 4 7 with the WE marking on the plug onto the metal contact of the working electrode ...

Page 42: ...3 2 Equipping the MME measuring head 34 884 Professional VA Figure 18 Connecting the working electrode ...

Page 43: ...nert gas inlet N2 4 10 in the connection 19 2 for the MME pro NOTE Observe see Chapter 3 2 4 page 42 for information on con necting the inert gas supply 5 Adjusting the needle valve Adjust the needle valve in accordance with the instructions in the Multi Mode Electrode pro document 8 110 8018XX and the Elec trodes in VA multimedia guide A 717 0002 6 Testing the electrode function Test the electrod...

Page 44: ... from the storage vessel The reference electrode that is part of the accessories is already filled with reference electrolyte c KCl 3 mol L 2 Fill the electrolyte vessel with bridge electrolyte e g c KCl 3 mol L in accordance with the information in the electrode leaflet 3 Allow the bridge electrolyte to react in the electrolyte vessel until the diaphragm is soaked with bridge electrolyte 4 Place ...

Page 45: ...Insert the installed reference electrode into the opening 5 20 of the measuring head insert 7 CAUTION The electrode cables for the reference working and auxiliary elec trode are identical Observe the markings on the plugs because the three cables must not be mixed up Plug the electrode cable 4 7 with the RE marking on the plug onto the metal contact of the reference electrode ...

Page 46: ... AE Pt auxiliary electrode 6 0343 100 Included in standard delivery Electrode holder 6 1241 120 and glassy carbon rod 6 1247 000 Together form the optionally available glassy carbon auxiliary electrode The Pt auxiliary electrode 6 0343 000 included in standard delivery can be inserted directly into the measuring head The optionally available GC auxiliary electrode has to be put together first ...

Page 47: ...247 000 Assembling the GC auxiliary electrode Proceed as follows to assemble the optionally available GC auxiliary elec trode 1 CAUTION Glassy carbon is a brittle very fragile material proceed with cau tion when inserting it into the electrode holder and handling it In the event the GC rod breaks the remaining part in the holder can be removed by pulling out the retaining ring 22 6 Insert the glas...

Page 48: ... into the measuring head 1 Insert the auxiliary electrode into the opening 5 23 of the measur ing head insert 2 CAUTION The electrode cables for the reference working and auxiliary elec trode are identical Observe the markings on the plugs because the three cables must not be mixed up Plug the electrode cable 4 7 with the AE marking on the plug onto the metal contact of the auxiliary electrode ...

Page 49: ...asuring head Once the MME measuring head has been fully equipped it can be inser ted on the measuring head arm Proceed as follows to do this 1 Tilt the measuring head arm up 2 CAUTION Do not apply pressure to the drive disk on the connector plate of the measuring head arm as this could damage the stirrer motor ...

Page 50: ...with an audible click Figure 25 Inserting the measuring head 3 2 4 Connecting the inert gas supply Generally nitrogen N2 is used as the inert gas for deaerating the measur ing solution and for operating the MME pro Only nitrogen of sufficient purity may be used for this For general polarography voltammetry 4 5 w N2 99 995 For analyses in organic solvents for determinations that result in very high...

Page 51: ...e buffer solution add the base electrolyte For measurements in organic solvents add the solvent being used Screw the gas washing glass back onto the measuring head arm Figure 26 Gas washing glass 2 Connecting the inert gas inlet Connect one end of the PVC tubing 6 1801 080 on the N2 nip ple of the 884 Professional VA Connect the other end of the PVC tubing 6 1801 080 to the inert gas bottle connec...

Page 52: ...measuring head cover at an angle of approx 45 in the guide bolt in the front part of the measuring head insert 2 WARNING If the measuring head cover is installed without due care this may result in injury to the hand Make sure that your fingers do not get caught between the meas uring head cover and the measuring head Fold back the measuring head cover and gently push it in place The measuring hea...

Page 53: ...DE measuring head directly on the meas uring head arm Preparing the measuring head The measuring head is supplied with a measuring head cover mounted in place The measuring head must first be placed on the measuring head arm Proceed as follows 1 Tilt the measuring head arm up 2 CAUTION Do not apply pressure to the drive disk on the connector plate of the measuring head arm as this could damage the...

Page 54: ...one hand to hold the measuring head arm on the rear and use the other hand to insert the measuring head into the connector plate of the measuring head arm The measuring head must snap into place with an audible click Figure 30 Inserting the measuring head 3 Remove the stopper from the pipetting opening ...

Page 55: ...ving the stopper from the pipetting opening 4 Pull the slide lock on the top of the measuring head cover towards you and at the same time tilt the measuring head cover to an angle of approx 45 and remove it 1 2 Figure 32 Removing the measuring head cover ...

Page 56: ...rument housing Lower the measuring head arm again CAUTION The measuring head insert is made of PTFE Do not use sharp objects around it to ensure the material is not damaged 3 3 1 Connecting the gas inlet 1 Connecting the gas inlet Insert the PTFE tubing for adding gas to the solution 6 1829 030 through the opening Pull the transparent inner tubing through as far as it will go Ensure that the green...

Page 57: ...ation 884 Professional VA 49 Figure 33 Inserting the gas inlet Connect the tubing to the PURGE threaded opening 4 8 and tighten it hand tight Finally tighten the tubing nipple using the wrench provided 6 2739 000 ...

Page 58: ...orking electrode WE Reference electrode RE Auxiliary electrode AE NOTE Please also observe the notes contained in the electrode leaflets sup plied with the electrodes In addition you can learn how to best handle the electrodes from the multimedia guide A 717 0002 NOTE If you are using the instrument for voltammetric applications the gas inlet has to be connected beforehand see Chapter 3 3 1 page 4...

Page 59: ...from the electrode tip Figure 35 Removing the protective cap from the electrode tip 2 Assembling the working electrode Hold the driving wheel by the driving axle and tighten the electrode tip to the driving axle Figure 36 Tightening the electrode tip to the driving axle 3 Inserting the working electrode into the measuring head insert Insert the working electrode into the opening 9 21 of the measur...

Page 60: ...belt 6 1244 050 over the drive shaft 8 9 guide it on both sides over the guide roller 8 13 from below pull it over the working electrode and fasten it in the driving wheel of the driving axle Figure 38 Fastening the drive belt NOTE Make sure that the drive belt does not rub against the driving axle or surrounding components tubing cables etc ...

Page 61: ...the three cables must not be mixed up Plug the electrode cable 8 7 with the WE marking on the plug onto the metal contact of the driving axle Figure 39 Connecting the working electrode 3 3 2 2 Reference electrode RE The reference electrode consists of the following two articles Reference electrode filled with reference electrolyte e g 6 0728 130 Electrolyte vessel filled with bridge electrolyte e ...

Page 62: ...electrolyte e g c KNO3 1 mol L in accordance with the information in the electrode leaflet 3 Allow the bridge electrolyte to react in the electrolyte vessel until the diaphragm is soaked with bridge electrolyte 4 Place the reference electrode in the filled electrolyte vessel and screw it in place The electrolyte solution that is displaced in the electrolyte vessel is forced out of the deaeration o...

Page 63: ...e measuring head insert 7 CAUTION The electrode cables for the reference working and auxiliary elec trode are identical Observe the markings on the plugs because the three cables must not be mixed up Plug the electrode cable 8 7 with the RE marking on the plug onto the metal contact of the reference electrode ...

Page 64: ...electrode Proceed as follows 1 Insert the auxiliary electrode into the opening 9 23 of the measur ing head insert 2 CAUTION The electrode cables for the reference working and auxiliary elec trode are identical Observe the markings on the plugs because the three cables must not be mixed up Plug the electrode cable 8 7 with the AE marking on the plug onto the metal contact of the auxiliary electrode...

Page 65: ... 3 Installation 884 Professional VA 57 3 3 3 Installing the measuring head cover For the procedure see Chapter 3 2 5 page 44 ...

Page 66: ...nly personnel who have been issued Metrohm qualification may perform service and repair work on electrical and electronic parts Connecting the power cord Accessories Power cord three core with IEC 60320 instrument plug type C13 Con ductor cross section 1 mm2 18 AWG Power plug according to customer requirement 6 2122 XX0 Do not use a not permitted power cord 1 Plugging in the power cord Plug the po...

Page 67: ...ion feature If you wish to pull out the plug you first need to pull back the outer plug sleeve 2 Connect the USB plug of the controller cable to an available USB connector on the PC Initializing the 884 Professional VA in viva Proceed as follows 1 Start viva The following dialog window is displayed 2 Click on Yes The following dialog window is displayed ...

Page 68: ... instruments electrically 60 884 Professional VA 3 Change the suggested instrument name if required 4 Confirm with OK The instrument will be automatically listed in the device table of the Configuration program part ...

Page 69: ... VA only with the measuring head in place and the measuring head arm lowered 1 Insert the measuring head as described in Preparing the measuring head page45 2 Equip the measuring head with the electrodes see Chapter 3 3 2 page 50 3 Insert the measuring vessel into the holder 1 3 4 WARNING If the measuring head arm is lowered without due care this may result in injuries to the hands Make sure that ...

Page 70: ...he detailed man ual In viva proceed as follows 1 Select the 884 Professional VA in the device table of the Configura tion section of the program 2 In the device table click on the Edit button and select Properties 3 Open the Calibrator tab 4 Click on Activate calibrator and then on OK The set to work date of the calibrator and the calibrator s serial num ber are displayed on the Calibrator tab aft...

Page 71: ...n certificate is available online Go to http www metrohm com en support and service certificate finder and enter the serial number of the calibrator and download the certifi cate 5 If required adjust the settings on the Calibrator tab e g Message or Action ...

Page 72: ...N LED blinking pattern indicates standby potential The electrodes may be damaged Check the blinking pattern of the Status LED The measuring head may not be removed while standby potential is being applied to the electrodes blinking pattern on for a long time off for a short time CAUTION Stirrer motor is in operation The stirrer motor may be damaged Switch off the stirrer motor before you remove or...

Page 73: ...ference electrode must be removed from the measuring head and stored separately Observe the notes on maintenance and care in the electrode leaflet 4 Figure 42 Rear WASTE connector When using a Multi Mode Electrode pro along with additional auto mated aspiration of the measuring solution watch for traces of mer cury in the indicated connector WASTE when removing the MME measuring head Remove any tr...

Page 74: ... the rear of the measuring head arm and use the other hand to insert the new measuring head into the connector plate of the measuring head arm The measuring head must snap into place with an audible click 6 WARNING If the measuring head arm is folded down without due care this may result in injuries to the hands Make sure that your fingers do not get caught between the meas uring head arm and the ...

Page 75: ...mmy cell test method template in viva 2 Plug the three electrode cables onto the contacts of the dummy cell 6 2813 050 Observe the correct assignment of the electrode cables WE RE and AE 3 Place the measuring head cover and the stopper 7 5 onto the measuring head 4 Start the determination at the prompt select the name of the 884 Professional VA being used from the list and wait until the measure m...

Page 76: ...test 68 884 Professional VA Figure 44 Dummy cell test Ideal curve progression 5 If the resulting curve is not consistent with this representation and the problems with the determinations persist contact the local Met rohm Service ...

Page 77: ...nnected Check the electrode cable connections One or several electrodes are defective Perform maintenance in accordance with the electrode leaflet You can find more detailed information at http va electrodes met rohm com The measuring vessel con tains too little solution or is empty Check the fill level in the measuring vessel and add solution if necessary The measured val ues are widely scat tere...

Page 78: ...tenance procedure for the reference electrode in accordance with the electrode leaflet You can find more detailed information at http va electrodes met rohm com One or more of the solu tions in use water electro lyte VMS etc has become contaminated Apply fresh solution use water from a differ ent source 6 1 2 884 Professional VA for VA trace analysis Problem Cause Remedy A peak is not found in eit...

Page 79: ...position time for stripping voltammetry is too short In the voltammetry command DP SQW increase the deposition time under Potentio static pretreatment A slight hissing noise can be heard at the measuring head The measuring head is not correctly locked in place on the instrument This can allow nitrogen to escape at the connection Remove the measuring head and put it back in place until it clearly c...

Page 80: ...ring solution Ensure the compatibility of the chemistry Replace the bridge electrolyte if necessary such as using a NaCl or KNO3 solution in place of KCl Curves have a large amount of noise with DME SMDE The electrode drips at irreg ular intervals Check the tapping of the dripping on the MME pro If necessary center the capillary in the MME pro or readjust the anchoring of the capillary using the w...

Page 81: ...massively increase the chloride concen tration Formation of sparingly soluble compounds e g Fe III in a neutral or alka line solution Optimize the measuring solution e g Use a different electrolyte for a different pH value Add a complexing agent such as citrate No spiking all elec trode types The wrong standard solu tion has been used or the concentration is too low Increase the volume of the stan...

Page 82: ...ough the pipetting opening Instead of manual pipetting automatically add standard solution using an 800 Dos ino Pipetting standard solutions has to be car ried out by the same person or with the same instrument and the same pipette Use the pipetting unit correctly If necessary have the pipettes calibrated GLP Organic constituents inter fere with analysis Carry out UV digestion or equivalent sample...

Page 83: ...ase current and Curves have a large amount of noise The peak is in the uppermost mA range all electrode types The concentration of the ion to be determined is too high Reduce the sample volume run the analysis again The peak is in the uppermost mA range with HMDE The deposition time in the viva method in the vol tammetry command under Potentiostatic pretreat ment is too long Reduce the deposition ...

Page 84: ...ion have shifted The wrong peak is evalu ated in the sample all of the electrode types The standard solution is too heavily acidulated Reduce the pH value of the standard solution The buffer capacity of the electrolyte is not sufficient Increase the electrolyte volume The electrolyte solution is too old Produce new electrolyte solution Organic additives may only last 1 day or less Unstable or abno...

Page 85: ...eedle and capillary If necessary replace the capillary or needle see the Multi Mode Electrode pro docu ment 8 110 8018XX The tapping mechanism on the VA stand base is not functioning correctly Check the positioning of the capillary in the MME pro The capillary has to be centered in the retaining screw The retaining screw is too loose or tight ened too tightly Use the wrench for the MME 6 1247 220 ...

Page 86: ...ee the Multi Mode Electrode pro document 8 110 8018XX The tapping mechanism is not functioning correctly Check the tapping of the drops 6 1 3 884 Professional VA for CVS Problem Cause Remedy Conditioning takes a long time The reference electrode has not yet reached equili brium After maintenance of the reference electrode wait for at least 20 min before starting a meas urement The working electrod...

Page 87: ... acid for 1 to 2 seconds and then thoroughly rinse with distilled water An incorrect potential was applied because the meas uring vessel contains too little measuring solution All three electrodes must be immersed in the measuring solution Dip the electrode tip of the working elec trode and or the auxiliary electrode into concentrated nitric acid for 1 to 2 seconds and then thoroughly rinse with d...

Page 88: ...not decrease in spite of suppressor addition No chloride is contained in the Cu VMS Check the preparation of the Cu VMS and modify it if required The wrong dosing unit is being used for the addition of standard solution or the dosing unit contains the wrong solution Check the automatic solution addition The concentration of the standard solution or the sample is too low Add a larger volume or use ...

Page 89: ...onnector 1 Connector 1 6 1805 550 250 2 00 Connector 2 Connector 2 6 1805 550 250 2 00 Connector 3 Connector 3 6 1805 550 250 2 00 Connector SMP Connector SMP 6 1831 020 220 0 75 Connector WASTE Connector WASTE 6 1805 050 and 6 1805 540 210 and 80 2 00 Connector OUT Connector OUT 6 1805 550 250 2 00 7 2 Status LED Various instrument statuses The Status LED on the front of the instrument indicates ...

Page 90: ...Under Find products accessories and applications by enter the article number e g 2 884 XX10 The search result is displayed 3 Under Products click on More information Detailed information regarding the product is shown on various tabs 4 On the Included parts tab click on Download the PDF The PDF file with the accessories data will be created NOTE When you receive your new instrument we recommend do...

Page 91: ...disk 41 45 Tubing connector 23 Measuring head cover Install 44 Remove 26 47 MME measuring head Also see MME measuring head 13 Parts 13 MME measuring head arm Tubing connector 17 MME measuring head connector plate Detail view 14 MME measuring head insert Detail view 16 P Power connection 58 R RDE See also Working electrode 32 51 RDE measuring head Parts 19 See also RDE measuring head 19 RDE measuri...

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