Metrohm 806 Manual
Metrohm 806 is a versatile buret unit that can be operated with various Metrohm dosing devices or titrators. The 806 Exchange Unit is suitable for simple dosings or titrations. Specifications concerning the exchange unit and the reagent can be stored in the integrated data chip. This data can be read out and updated by a suitable instrument.
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806 Exchange Unit
Manual
8.806.8003EN / 2019-09-26
Metrohm AG
CH-9100 Herisau
Switzerland
Phone +41 71 353 85 85
Fax +41 71 353 89 01 [email protected]
www.metrohm.com
806 Exchange Unit
Manual
8.806.8003EN / 2019-09-26
Technical Communication
Metrohm AG
CH-9100 Herisau [email protected]
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.
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Table of contents
Table of contents
1
About the documentation ................................................... 1
Symbols and conventions ........................................................ 1
Safety instructions ................................................................ 2
Tubing and capillary connections ............................................. 2
Flammable solvents and chemicals ........................................... 2
Filling the dosing cylinder ........................................................ 3
Recycling and disposal ......................................................... 3
2 Construction of the 806 Exchange Unit
4
Total view .............................................................................. 4
Components of the 806 Exchange Unit .............................. 6
9
Setting up the instrument .................................................... 9
Packaging ................................................................................ 9
Checks .................................................................................... 9
Location .................................................................................. 9
Start-up .................................................................................. 9
Preparing the exchange unit .................................................... 9
Attaching the exchange unit .................................................. 10
Filling the tubings .................................................................. 12
Buret tips ............................................................................... 13
Removing the exchange unit ................................................. 14
Mounting the components ................................................ 14
Mounting the thermostat casing ............................................ 14
Mounting the flat stopcock ................................................... 16
Mounting the tubings on the flat stopcock ............................ 17
Filling the dosing cylinder and dosing .............................. 19
Care and upkeep ................................................................. 21
Disassembling the exchange unit ........................................... 21
Cleaning the cylinder and piston ............................................ 22
Assembling the exchange unit ............................................... 23
Flat stopcock blocked ............................................................ 24
Chemical resistance and materials .................................... 25
Solutions ............................................................................... 25
Body ...................................................................................... 25
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Table of contents
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Materials ............................................................................... 25
GLP - Validation .................................................................. 26
Problems .............................................................................. 27
Buret data ........................................................................... 30
Dosing accuracy .................................................................. 30
Typical measurement deviation .............................................. 30
The ISO/EN/DIN standard 8655-3 ........................................... 31
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Table of figures
Table of figures
806 Exchange Unit ............................................................................ 4
806 Exchange Unit - Components ..................................................... 6
Thermostat casing ........................................................................... 15
Flat stopcock ................................................................................... 16
Dosing/Filling .................................................................................. 19
806 Exchange Unit
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1 Introduction
1 Introduction
The 806 Exchange Unit is a versatile buret unit which can be operated with various Metrohm dosing devices or titrators. The 806 Exchange Unit is suitable for simple dosings or titrations.
Specifications concerning the exchange unit and the reagent can be stored in the integrated data chip. This data can be read out and updated by a suitable instrument.
1.1 About the documentation
1.1.1 Symbols and conventions
The following symbols and styles are used in this documentation:
Method
File ▶ New
[Next]
Cross-reference to figure legend
The first number refers to the figure number, the second to the instrument part in the figure.
Instruction step
Carry out these steps in the sequence shown.
Dialog text , parameter in the software
Menu or menu item
Button or key
Warning
This symbol draws attention to a possible life hazard or risk of injury.
Warning
This symbol draws attention to a possible hazard due to electrical current.
Warning
This symbol draws attention to a possible hazard due to heat or hot instrument parts.
Warning
This symbol draws attention to a possible biological hazard.
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1.2 Safety instructions
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Caution
This symbol draws attention to a possible damage of instruments or instrument parts.
Note
This symbol marks additional information and tips.
1.2 Safety instructions
1.2.1 Tubing and capillary connections
CAUTION
Leaks in tubing and capillary connections are a safety risk. Tighten all connections well by hand. Avoid applying excessive force to tubing connections. Damaged tubing ends lead to leakage. Appropriate tools can be used to loosen connections.
Check the connections regularly for leakage. If the instrument is used mainly in unattended operation, then weekly inspections are mandatory.
1.2.2 Flammable solvents and chemicals
WARNING
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All relevant safety measures are to be observed when working with flammable solvents and chemicals.
Set up the instrument in a well-ventilated location.
Keep all sources of flame far from the workplace.
Clean up spilled liquids and solids immediately.
Follow the safety instructions of the chemical manufacturer.
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1.2.3 Filling the dosing cylinder
CAUTION
1 Introduction
If a buret tip is clogged, then it could happen that no liquid will be aspirated when the dosing cylinder is being filled. A vacuum can arise as a result.
If you then remove the exchange unit from the instrument, the piston could destroy the dosing cylinder.
Do not fail to loosen the tubing connections on the dosing cylinder first, before you remove the exchange unit. This will eliminate the vacuum.
1.3 Recycling and disposal
This product is covered by European Directive 2012/19/EU, WEEE – Waste
Electrical and Electronic Equipment.
The correct disposal of your old instrument will help to 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.
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2.1 Total view
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2 Construction of the 806 Exchange Unit
2.1 Total view
4
5
6
7
8
1
2
3
13
14
15
16
10
11
12
17
1 Tubing connection (6.1805.080)
4 ￭￭￭￭￭￭￭￭
9
Figure 1 806 Exchange Unit
2 Threaded stopper (6.1446.080)
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3 Bottle attachment (6.1602.105)
Of PFA/PP, thread GL45
5 PCTFE/PTFE flat stopcock (6.1542.020)
Or ceramic stopcock 6.1542.010
7 Plate holder (6.2046.070)
For name plates
9 Data chip
On the underside of the buret
11 SGJ clip (6.2023.020)
Of POM
13 Bottle with thread (6.1608.23)
Amber glass, thread GL45
15 Link stopper (6.1446.030)
17 Body (6.1576.XXX)
.110 for 1 mL cylinder
.150 for 5 mL cylinder
.210 for 10 mL cylinder
.220 for 20 mL cylinder
.250 for 50 mL cylinder
2 Construction of the 806 Exchange Unit
4 Tubing connection (6.1805.010)
Length 13 cm (6.1805.050 with 1 mL cyl.)
6 Storage vessel (6.1228.000)
For buret tips or electrodes
8 Nominal volume
10 Adsorber tube (6.1619.010)
Adsorber tube 6.1619.010
12 Tubing connection (6.1805.100)
Length 40 cm
14 Antidiffusion tip (6.1543.200)
Of ETFE/FEP, for titrations
16 Storage vessel (6.1228.000)
For buret tips or electrodes
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2.2 Components of the 806 Exchange Unit
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2.2 Components of the 806 Exchange Unit
Figure 2 806 Exchange Unit - Components
1 Tubing connection (6.1805.080)
Length 25 cm
3 Tubing connection (6.1805.010)
Length 13 cm (6.1805.050 with 1 mL cyl.)
5 Torque key (6.2739.000)
For loosening tubing nipples
7 Insert for key (6.2739.030)
For loosening the light protection
2 Tubing connection (6.1805.100)
Length 40 cm
4 Threaded stopper (6.1446.080)
6 Paraffin fat (6.2803.010)
For dosing pistons, 2 g
8 Light protection (6.1563.030)
Of PETG
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9 Mounting ring for the cylinder
(6.2045.XXX)
.000 for 5, 10 mL cylinder
.010 for 20 mL cylinder
.020 for 50 mL cylinder
11 Dosing cylinder (6.1518.XXX)
Clear glass
.113 1 mL cylinder
.150 5 mL cylinder
.210 10 mL cylinder
.220 20 mL cylinder
.250 50 mL cylinder
13 Plate holder (6.2046.070)
For name plates
15 Storage vessel (6.1228.000)
For buret tips or electrodes
17 Adsorber tube (6.1619.010)
Adsorber tube 6.1619.010
19 SGJ clip (6.2023.020)
Of POM
21 Canula (6.1819.020)
Of FEP, thread M6
23 Holding clamps (6.2043.005)
For reagent bottles
25 PTFE piston (6.1556.XXX) with coupling
.110 for 1 mL cylinder
.150 for 5 mL cylinder
.210 for 10 mL cylinder
.220 for 20 mL cylinder
.250 for 50 mL cylinder
2 Construction of the 806 Exchange Unit
10 Name plates (6.2244.020)
For labeling the reagent, 10 x
12 Flat stopcock
PCTFE/PTFE 6.1542.020
Ceramic 6.1542.010
14 Switching lever
For switching the flat stopcock
16 Nominal volume
18 Adapter NS14 for adsorber tube
Of ETFE
20 Bottle attachment (6.1602.105)
Of PFA/PP, thread GL45
22 Bottle with thread (6.1608.23)
Amber glass, thread GL45
24 Storage vessel (6.1228.000)
For buret tips or electrodes
26 Antidiffusion tip (6.1543.200)
Of ETFE/FEP, for titrations
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2.2 Components of the 806 Exchange Unit
27 Dosing tip open (6.1543.060) of ETFE/FEP, for dosings
29 Body (6.1576.XXX)
.110 for 1 mL cylinder
.150 for 5 mL cylinder
.210 for 10 mL cylinder
.220 for 20 mL cylinder
.250 for 50 mL cylinder
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28 Link stopper (6.1446.030)
30 Data chip
On the underside of the buret
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3 Installation
3 Installation
3.1 Setting up the instrument
3.1.1 Packaging
The instrument is supplied in protective packaging together with the separately packed accessories. Keep this packaging, as only this ensures safe transportation of the instrument.
3.1.2 Checks
Immediately after receipt, check whether the shipment has arrived complete and without damage by comparing it with the delivery note.
3.1.3 Location
The instrument has been developed for operation indoors and may not be used in explosive environments.
Place the instrument in a location of the laboratory which is suitable for operation and free of vibrations and which provides protection against corrosive atmosphere and contamination by chemicals.
The instrument should be protected against excessive temperature fluctuations and direct sunlight.
3.2 Start-up
3.2.1 Preparing the exchange unit
Proceed as follows:
1 Mount the holding clamps in such a way that the reagent bottle rests safely on the exchange unit.
2 Check whether the reagent bottle contains solvent.
3 Fill the adsorber tube with a suitable adsorber material.
CO
2
adsorption: Soda lime
KF reagent: Molecular sieve
If no special adsorber material is necessary, the adsorber tube may also be used as dust filter when filled with cotton.
4 Attach the filled adsorber tube onto the reagent bottle.
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3.2 Start-up
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5 Control, whether the tubing connections are fastened. Tighten the tubing connection with the 6.2739.000 key if necessary.
NOTICE
Do not use any other aids! The threads of the tubing nipples and the tubing openings may not be deformed.
6 Write the name of the solvent in the reagent bottle on a colored plate.
7 Slide the plate into the labeling holder.
8 Store the buret tip or the electrode in the two storage vessels.
Usage of original reagent bottles
You may eventually need a special bottle attachment or a thread adapter in addition to the supplied 6.1602.105 standard bottle attachment:
Bottle attachment
Bottles with GL45 thread
Bottles with S40 thread
Bottles with GL32 thread
Bottles with 28 mm thread
Standard
Order number
6.1602.115
6.1602.105 / 6.1618.000
6.1602.105 / 6.1618.010
3.2.2 Attaching the exchange unit
Attach an 806 Exchange Unit as follows:
1 Before attaching the exchange unit, check whether the stopcock can be switched manually by the switching lever.
For attaching, the switching lever must be directed to the right (stopcock in dosing position). The arrow marking must point upwards.
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3 Installation
2 Check the position of the piston rod on the underside of the exchange unit.
The recess of the piston rod must be tight with the buret base and the smooth surface with the opening must be directed to the rear.
3 Correct the position of the piston rod with the 6.2739.010 key if necessary.
NOTICE
In case of carelessly handling the 6.2739.010 key, the data chip of the exchange unit may be damaged. Avoid touching the white ceramic holder of the data chip!
4 Attach the exchange unit from the front onto the control device and push all the way to the rear, so that it snaps in and the LED Status flashes slowly.
It must snap in audibly.
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3.2 Start-up
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5 If the exchange unit does not snap in, check the following:
Position of the piston rod
Stopcock position of the exchange unit
The switching lever must be directed to the right (stopcock in dosing position). The arrow marking must point upwards ( see step 1 ).
If the exchange unit is attached correctly, its initialization is being activated by a micro switch which is triggered by the guide bolts of the exchange unit. It is being recognized and the data is being read automatically from the data chip.
The control device automatically rotates the stopcock and returns the stopcock in dosing position.
After this, the LED Status on the control device lights up constantly.
3.2.3 Filling the tubings
The proceeding during the filling of the tubings of the exchange unit depends on the control device and control software. Consult the corresponding manual for manual dosing and filling.
The function Preparing or PREP of the control software is used to rinse the cylinder and tubings of the exchange unit and fill them air bubble-free.
You should carry out this function before the first determination or once per day.
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3 Installation
3.2.4 Buret tips
The following buret tips are included in the standard equipment of the dosing unit:
6.1543.060
6.1543.200
Open dosing tip 6.1543.060
For tasks during which the top is not immersed, e.g. dosings.
The buret tip can be stored in the same solvent as the one contained in the reagent in order to prevent reagent crystallization.
We recommend that the storage vessel be filled with solvent and that the buret tip be placed inside it. In the event that KF reagent is used as the titrant, use methanol or ethanol for storing the dosing tip.
Antidiffusion tip 6.1543.200
It is used for work requiring the immersion of the tip, e.g. titrations.
This tip prevents the diffusion of liquids into the buret tip.
The pressure of the surrounding liquid and the internal stress of the membrane press on the tubing end, thus sealing off the opening.
The backpressure of the dosed liquid is overcome during the dosing process. The membrane opens up the tubing end. The tubing end is sealed off again automatically after the dosing is completed.
CAUTION
Do not disassemble the antidiffusion tip.
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3.3 Mounting the components
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3.2.5 Removing the exchange unit
To remove the exchange unit, proceed as follows:
1 Carry out the 'Filling' function on the control device.
NOTICE
Do not try to remove the exchange unit when the piston of the exchange unit or the piston rod of the drive is in zero position.
2 Carefully remove the exchange unit to the front.
If it is not possible to remove the exchange unit, check the status of the control device.
3 If the control device is still busy, press the key <STOP> and wait until the device is ready.
4 If the control device is overloaded and a corresponding error message is displayed, switch it off and on again.
5 If the device is displaying that it is busy with filling the cylinder but apparently nothing happens, the filling rate is maybe set too low. Try to increase the filling rate and wait until the device is ready.
3.3 Mounting the components
3.3.1 Mounting the thermostat casing
If a solvent with a constant temperature is necessary for a titration, the
6.1563.040 thermostat casing is used. Water with a certain temperature is pumped through the thermostat casing and this way the temperature of the content in the dosing cylinder is kept constant.
The thermostat casing may only be used with a thermostat equipped with a pressure and suction pump (the feeding pressure must not be too high).
The thermostat casing may only be used in a temperature range from
15...50 °C.
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3 Installation
806 Exchange Unit
Figure 3 Thermostat casing
Mount the thermostat casing as follows:
1 Loosen the tubing connection to the glass cylinder.
2 Unscrew the light protection.
3 Screw out the glass cylinder with holder.
4 Loosen the screw nipple on the glass cylinder.
5 Roll the O-ring out of the groove and upwards on the glass nozzle.
Do not use any hard items to remove the O-ring, otherwise the edge of the glass nozzle may chip off!
6 Replace the union nut of the cylinder by the sealing ring of the thermostat casing (threaded side upwards).
7 Slightly grease the O-ring and attach it on the glass nozzle.
8 Fasten the sealing ring with the screw nipple.
9 Insert the glass cylinder with holder into the thermostat casing and press firmly.
10 Tighten the thermostat casing with the cylinder in the body.
11 Connect the thermostat tubings.
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3.3 Mounting the components
3.3.2 Mounting the flat stopcock
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Figure 4 Flat stopcock
Mount the flat stopcock as follows:
1 Check whether the flat stopcock can be moved. Twist the lower and upper part of the flat stopcock against each other. For mounting the stopcock, move the lower part to the right as far as the limit stop, i.e.
in clockwise direction.
2 Check whether the switching lever on the exchange unit is directed to the right.
3 Insert the stopcock into the holder
.
The rectangular recess of the stopcock is to be directed to the groove on the edge (on the left side) of the holder.
4 Check whether the stopcock can be moved by the switching lever.
5 Rotate the switching lever to the right to the dosing position.
6 Attach the exchange unit onto the control device.
Types of flat stopcocks
There is a PCTFE/PTFE stopcock (6.1542..020, standard equipment) and a
6.1542.010 ceramic stopcock available, which can be ordered separately.
Generally, the ceramic stopcock is to be preferred if hard crystals can precipitate out of the solution. If only soft crystals precipitate or for reagents only occasionally used, we recommend the PCTFE/PTFE stopcock. The
PCTFE/PTFE stopcock is subject to a certain wearing. This stopcock has to be replaced more often than the ceramic stopcock.
We especially recommend the following type of flat stopcocks:
806 Exchange Unit
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3 Installation
Solution
Alkaline, aqueous
EDTA, complexone
HClO4 in glacial acetic acid
Iodine solution
Karl Fischer reagent
KOH in ethanol
Organic solvents
Permanganate, KMnO4
Acids, aqueous
Silver nitrate, AgNO3
TBAOH
Thiosulphate, Na2S2O3
PCTFE/PTFE
6.1542.020
•
•
•
•
•
•
•
•
•
•
•
•
3.3.3 Mounting the tubings on the flat stopcock
Mounting the tubings on the flat stopcock
Ceramic
6.1542.010
•
•
•
•
•
6.1805.100
6.1805.080
6.1805.010
806 Exchange Unit
1 Fasten the 6.1805.080 tubing on the flat stopcock and on the bottle attachment of the reagent bottle.
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3.3 Mounting the components
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2 Fasten the 6.1805.010 tubing on the flat stopcock and on the dosing cylinder.
3 Fasten the 6.1805.100 tubing on the flat stopcock.
4 Fasten the buret tip on the 6.1805.100 tubing.
5 Tighten the tubing connection by hand or with the 6.2739.000 key if necessary.
NOTICE
Do not use any other aids! The thread of the tubing nipple and the tubing openings may not be deformed.
6 Carry out 'Filling'.
7 Fill the tubings by several dosings and fillings of the cylinder or with the PREP/Prepare function.
By the several dosings and fillings, the air bubbles are driven out. It is important that the tubing connection between the buret and the flat stopcock is bubble-free. If necessary, knocking against the tubings helps to remove the bubbles remained.
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4 Mode of operation
4.1 Filling the dosing cylinder and dosing
4 Mode of operation
1 5
6
7
2
3
4
Figure 5 Dosing/Filling
1 Filling tube
For aspirating the solvent out of the reagent bottle.
3 Dosing piston
For ejecting and aspirating a solution.
5 Dosing tubing
For dosing the solvent via the dosing tip.
2 Dosing cylinder
Contains the solution for dosing. Volume
1 mL , 5 mL , 10 mL , 20 mL or 50 mL .
4 Piston rod
With coupling. For moving the dosing piston in the dosing unit.
6 Flat stopcock
For switching between filling and emptying the dosing cylinder.
7 Switching lever
For manually switching the flat stopcock.
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4.1 Filling the dosing cylinder and dosing
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When ejecting the titrant, the piston rod of the drive moves upwards the dosing piston in the dosing cylinder. The flat stopcock is in dosing position. The switching lever is directed to the right. The liquid in the cylinder is pushed trough the flat stopcock into the dosing tubing.
After switching the flat stopcock, i.e. rotating the flat stopcock (switching lever is directed to the left), liquid is aspirated out of the filling tubing as a result of the dosing piston being pulled downwards by the piston rod of the drive.
Because of the fact that the exchange units are interchangeable, the coupling of the piston rod exhibits a low mechanical tolerance which has an effect on the accuracy of the dosing when the dosing piston changes its direction of movement. This tolerance is mechanically compensated by the drive during automated procedures.
The piston movements are controlled by the precise electronic fine mechanics of the drive. Independent of the cylinder volume, it exhibits a resolution of 20'000 increments across the entire piston stroke.
The rate, at which a solution is to be dosed and the rate, at which the cylinder is to be filled, depend on the cylinder volume of the exchange unit.
The maximum and minimum filling and dosing rates are:
Cylinder volume (mL) max. filling- dosing rate
(mL/min) min. filling- dosing rate ( µ L/ min)
1
3
5
15
10
30
20
60
10 (depending on device)
50
150
NOTICE
Enter lower rates for high-viscosity liquids.
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806 Exchange Unit
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5 Handling and maintenance
5 Handling and maintenance
5.1 Care and upkeep
The exchange unit needs appropriate care.
NOTICE
Exchange units must be monitored regularly and cleaned from time to time.
Monthly inspections are called for in the event that alkaline, corrosive or high-concentration reagents are used. If non-problematic reagents are used, then the inspection intervals can be extended to several months.
5.1.1 Disassembling the exchange unit
It is recommended to disassemble and clean the exchange unit when replacing the reagent.
At the same time, the dosing piston and cylinder of the exchange unit can be checked. When using alkaline, corrosive or high-concentration reagents, it should be checked whether the glass cylinder has been attacked by e.g. aggressive alkalis or whether solids have crystallized out of the solution.
WARNING
Do not disassemble the exchange unit if it is still on the drive! Remove the exchange unit from the control device before loosening the tubing connections. Escaping reagents may access the inside of the device.
Proceed as follows:
1 Eject the reagent as far as possible without have the cylinder newly filled.
2 Loosen the tubing connection on the reagent bottle.
3 Move the piston to zero position, i.e. carry out 'Filling'.
4 Remove the exchange unit from the drive.
806 Exchange Unit
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5.1 Care and upkeep
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5 Remove all tubings.
6 Unscrew and remove the cylinder unit with light protection or the thermostat casing. If necessary for loosening the light protection, use the 6.2739.010 key (standard equipment of the dosing device or titrator) with the insert (6.2739.030).
7 Remove the cylinder holder with cylinder out of the light protection.
Press above on the screw connector.
8 Remove the holder of the glass cylinder upwards.
9 Thoroughly empty the cylinder with the 6.2739.010 key and carefully remove the piston.
5.1.2 Cleaning the cylinder and piston
Proceed as follows:
1 Check the leak-tightness of the dosing piston and cylinder.
If there is liquid under the piston, the dosing cylinder is not or not thoroughly greased. Inspect the dosing piston for deformations or damage to the sealing lips. The piston and the cylinder must be replaced in the event that any changes are discovered.
2 Clean the dosing cylinder and piston with a liquid cleaning agent.
Do not use any abrasive cleaning powder which could scratch the cylinder.
3 Afterwards, rinse the individual parts with plenty of deionised (or distilled) water.
4 Degreasing the piston and the glass cylinder is part of the cleaning procedure. Use a suitable cleaning agent or solvent and eventually an ultrasonic bath. Note the recommendations of the cleaning agent manufacturer.
5 Slightly grease the piston with paraffin grease (6.2803.010) on the sides. Wipe off the edge of the piston to avoid that the reagent will be in contact with the grease. Wipe off excess grease with a soft, lint-free cloth. Do not grease the piston for pipettings.
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5 Handling and maintenance
6 Check the piston and cylinder for any changes once more before assembling the exchange unit. If the dosing cylinder should exhibit scratches or rough areas, then it must be replaced.
5.1.3 Assembling the exchange unit
Mounting the cylinder
806 Exchange Unit
Proceed as follows:
1 Insert the greased piston (see above) carefully into the cylinder for approx. 1 cm.
2 Slide the cylinder holder from above over the cylinder (O-ring must be on the upper side) and press firmly.
3 Insert the cylinder with holder into the light protection and press firmly.
4 Attach the exchange unit onto the control device.
5 Dose manually until the piston rod of the drive protrudes just out of the body of the exchange unit.
6 Insert the cylinder with light protection from above into the cylinder holder.
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5.1 Care and upkeep
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7 Couple the piston rod with the push rod of the drive. The clamp of the push rod must tightly fit into the opening of the piston rod, see picture.
8 Carefully push the light protection downwards and tighten in the thread of the body. Thereby the dosing piston is pressed into the cylinder.
9 Dose manually and move the piston upwards to the limit stop.
5.1.4 Flat stopcock blocked
1 Check whether the stopcock is in dosing position. The switching lever must be directed to the right.
2 Loosen the flat stopcock out of the holder. Rotate the plate holder to the left and slightly lift the clip on the side of the holder with a finger nail or a sharp object. Then the flat stopcock can easily be removed from the holder.
3 Put the stopcock into a solvent.
with aqueous solutions – hot water with non-aqueous solutions – suitable solvent (see chapter 8) with KF reagent - methanol, then water, then methanol.
4 Eventually clean the stopcock with a suitable solvent (see above) in an ultrasonic bath and let it dry afterwards.
5 When the stopcock can be moved again, it can be inserted back into the exchange unit, see above.
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806 Exchange Unit
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5 Handling and maintenance
5.2 Chemical resistance and materials
5.2.1 Solutions
With the 806 Exchange Unit various solutions can be dosed. The materials of the individual components used have been selected for maximum resistance to chemicals and functionality.
It can however not be assumed that all types of aggressive or high-concentration solutions can be conveyed without difficulty. It is the responsibility of the user to determine the resistance of the various individual components to specific, aggressive media.
Many problems involving aggressive media can be prevented by regular cleaning and inspections.
5.2.2 Body
Metrohm exchange units are designed for usage with aqueous solutions and the most common solvents.
The temperature of the dosing material may not exceed 50°C. The exchange unit and its components cannot be autoclaved. The sterility of a germ-free dosing material cannot be guaranteed.
The body is made of polybutylene terephthalate. It is only partly resistant to chemicals.
Good resistance Acids, organic solvents
Limited resistance Alkalis (with a conc. > 1 M)
The exchange unit is not dishwater-safe. In most cases, the exchange unit is to be cleaned with lukewarm water and dishwashing detergent.
5.2.3 Materials
Body
Dosing piston
Dosing cylinder
Flat stopcock
Light protection
PBT (polybutylene terephthalate)
PTFE (polytetrafluoroethylene)
Borosilicate 3.3
PCTFE/PTFE or ceramic
PETG (polyethylene terephthalate, glycol-modified) or PVDF
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5.3 GLP - Validation
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5.3 GLP - Validation
Every drive and every dosing unit manufactured by the Metrohm Co. is subjected to rigorous quality controls prior to shipment. Every dosing unit is issued a quality certificate attesting conformance with the strict quality criteria of Metrohm. GLP ( G ood L aboratory P ractice) requires, among other things, periodic inspection of analytical measuring devices with respect to precision and correctness on the basis of standard operating procedures S tandard O perating P rocedure, SOP ). This may also include an inspection of dosing accuracy.
Recommended literature
￭
￭
Metrohm brochure "Quality management with Metrohm", detailed information concerning the principles and procedural methods of
Good Laboratory Practice
Metrohm Applications Bulletin 283/1 Validation of Metrohm burets
The validation of burets is carried out by the Metrohm service with special software.
The Metrohm agents worldwide offer the possibility of on-site inspections and certifications of dosing units and Dosinos with respect toaccuracy. It is recommended that an accuracy inspection be performed when the dosing cylinders and dosing pistons of a dosing unit are replaced.
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6 Troubleshooting
6 Troubleshooting
6.1 Problems
Problem
Air bubbles in the cylinder or in the dosing tubing
An incorrect volume is dosed
Data of the dosing unit cannot be read.
Exchange unit recognized either not at all or incorrectly.
Cause
Leaking connection
The reagent degasses excessively, e.g. released air forms bubbles.
The exchange unit has not correctly been attached.
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￭
￭
Remedy
Check the ends of the tubing, in particular that of the aspiration tubing.
Tighten all of the tubing connections with the wrench 6.2739.000.
Check the locking mechanism of the housing. Suggestion: Remove the housing and then reattach it.
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￭
￭
Carry out [PREP] / [Preparing]
Reduce the filling rate.
Suggestion: Degas the reagent with ultrasound, nitrogen or in a vacuum.
Wear
[PREP] / [Preparing] is not carried out or false parameters-
Dosing unit either mounted or assembled incorrectly.
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￭
Replacing piston and cylinder.
Carry out [PREP] / [Preparing]
Correct tubing length and diameter.
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￭
Remove the dosing unit and then reattach it.
Check whether the nominal volume on the housing and the effective cylinder volume match one another.
Data chip of the dosing unit mechanically damaged or impaired by chemicals.
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￭
￭
Remove the dosing drive and set it up again.
Clean the data chip and the contact surfaces.
Have the data chip replaced by the
Metrohm Service Dept.
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￭
￭
￭
Remove the exchange unit and set it up again.
Check the correct placing of the exchange unit.
Check the piston and flat stopcock position.
Switch the instrument off and on again.
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6.1 Problems
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Problem
No dosing takes place at all
Cause
Tubing connections are blocked or dosing unit is not assembled correctly.
￭
Remedy
If necessary contact the Metrohm Service
Dept.
￭
￭
￭
￭
￭
￭
Check whether the dosing tip is blocked.
Check whether the dosing tubing is connected to the correct port.
Check whether the dosing port is sealed off with a stopper.
Check whether the VENT port is sealed off with a stopper (vacuum in the supply bottle!). The VENT port must be open for pressure compensation.
Remove the dosing drive and check whether the dosing piston is connected to the dosing drive. The piston stopper must be flush with the upper side of the housing.
Check whether the connection cable is attached to the dosing drive.
Switch the flat stopcock manually to the exchange position (lever switch directed to the right).
Switch the piston rod to the right position.
It is not possible to attach the exchange unit.
The flat stopcock of the exchange unit is not in the exchange position.
The piston rod in the exchange unit is not in the right position.
It is being dosed or filled and/or the Titrando is not in the exchange position.
The exchange unit can not be removed and the "Status"
LED is flashing slowly.
Die "Status" LED does not light up, even though an exchange unit is attached.
The "Status" LED flashes rapidly.
The exchange unit has not correctly been attached.
The dosing drive is overloaded because the stopcock is blocked.
Stop the run or carry out a "filling".
Remove the exchange unit and attach it again until it snaps in. The LED flashes during data is read from an intelligent exchange unit and lights up constantly if the exchange unit has correctly been recognized.
Switch off the Touch Control or exit PC Control. Check wether the exchange unit can be removed. If it cannot be removed, check wether the flat stopcock still can be turned.
Switch it manually to the exchange position turning it to the right. Remove the exchange
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Problem
6 Troubleshooting
Cause
The dosing drive is overloaded because the piston is blocked.This error is displayed by the software
(Touch Control or PC Control / tiamo).
The data of the exchange unit cannot be read because the data chip has been damaged mechanically or by chemicals.
Remedy unit and proceed as described in the manual for the exchange unit.
Switch the control device off and then on again. The dosing device is being initialized during switching on. Remove the exchange unit and clean it as described in the manual for the exchange unit in chapter "Care and maintenance". Contact the Metrohm service if removing the exchange unit is not possible.
Have the data chip being replaced by the
Metrohm service.Until the data chip is being replaced you can remove the data chip yourself in order to be able to still use the exchange unit. The cylinder volume is automatically recognized nevertheless, but no data can be read from the exchange unit or be saved on it anymore.
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7.1 Buret data
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7 Appendix
7.1 Buret data
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￭
￭
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The 806 Exchange Unit is equipped with a data chip which contains the specifications for the exchange unit, the tubing connections and the reagent used.
Indications on exchange unit / tubing connections
Order number of the exchange unit
Serial number of the exchange unit
Serial number of the dosing cylinder
Length and diameter of the tubings on the dosing ports
Validation date etc.
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￭
￭
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Indications on the reagent
Name of the reagent
Titer of the reagent
Concentration of the reagent
Production and expiry date of the reagent etc
The 806 Exchange Unit makes it possible to read and overwrite data with the aid of a suitable device (e.g. Titrando). Consult the respective manual in order to determine whether the Metrohm device which you are using is capable of accomplishing this.
7.2 Dosing accuracy
Every exchange unit is subjected to a strict quality inspection prior to shipment. Every exchange unit is issued a quality certificate attesting conformance with the quality criteria of Metrohm.
7.2.1 Typical measurement deviation
The accuracy of exchange units can be seen in the following table. The values listed are to be regarded as typical values which can be achieved with a Titrando.
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7 Appendix
Table 1 Typical measurement deviation of Metrohm exchange units
Cylinder volume
1 mL
5 mL
10 mL
20 mL
50 mL max. systematic deviation
± 3 µ L
± 15 µ L
± 20 µ L
± 30 µ L
± 50 µ L
7.2.2 The ISO/EN/DIN standard 8655-3
The Metrohm exchange units fulfil the requirements of the ISO/EN/DIN standard 8655-3 Volume measurement instruments with pistons –
Part 3: Piston burets . Metrohm guarantees that its exchange units are in compliance with the following limit values at the time of shipment:
Table 2 Permissible limit values as per ISO/EN/DIN 8655-3
Cylinder volume
1 mL
5 mL
10 mL
20 mL
50 mL max. systematic measurement deviation
± 0.6 %
± 0.3 %
± 0.2 %
± 0.2 %
± 0.2 %
±
±
6 µ
15
L
µ L
± 20 µ L
± 40 µ L
± 100 µ L
±
±
± max. permissible measurement deviation
0.1 %
0.1 %
0.07 %
± 0.07 %
± 0.05 %
±
±
1
5
µ
µ
L
L
± 7 µ L
± 14 µ L
± 25 µ L
The Metrohm agents worldwide offer the possibility of on-site exchange unit inspections and certifications with respect to accuracy. We recommend that an accuracy inspection be performed when the dosing cylinders and dosing pistons of an exchange unit are replaced.
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8 Accessories
Up-to-date information on the scope of delivery and optional accessories for your product can be found on the Internet. You can download this information using the article number as follows:
Downloading the accessories list
1 Enter https://www.metrohm.com/ into your Internet browser.
2 Enter the article number (e.g. 806 ) into the search field.
The search result is displayed.
3 Click on the product.
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 is created.
NOTICE
Once you have received your new product, we recommend downloading the accessories list from the Internet, printing it out and keeping it together with the manual for reference purposes.
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Index
Index
A
Accuracy .................................. 26
Antidiffusion tip ........................ 13
B
Bottle attachment .................... 10
Buret data ................................ 30
Buret tip ................................... 13
Crystallizing ........................ 13
Storage .............................. 13
C
Certification .............................. 26
Crystallizing .............................. 13
D
Data chip ..................... 11, 29, 30
Data exchange ......................... 30
Dosing accuracy ....................... 26
Dosing cylinder ......................... 19
Material .............................. 25
Dosing piston ........................... 19
Material .............................. 25
Dosing position .......................... 9
Dosing tip
Open .................................. 13
Dosing tubing ........................... 19
E
Exchange unit ........................... 29
F
Filling tube ............................... 19
Flat stopcock ............................ 19
of ceramic .......................... 16 of PCTFE/PTFE ..................... 16
Function
PREP ................................... 12
Preparing ............................ 12
G
GLP .......................................... 26
Good Laboratory Practice ......... 26
L
LED
Status ..................... 11, 12, 28
Light protection
Material .............................. 25
O
Order number .......................... 30
P
PETG ........................................ 25
Piston blocked .......................... 29
Piston rod ....................... 9, 11, 19
Production date ........................ 30
Q
Quality certificate ..................... 26
Quality control .......................... 26
R
Reagent
Concentration .................... 30
Crystallizing ........................ 13
Expiry date ......................... 30
Name ................................. 30
Production date .................. 30
Titer ................................... 30
S
Serial number ........................... 30
SOP .......................................... 26
Stopcock
Material .............................. 25
Stopcock blocked ..................... 28
Storage vessel ........................... 13
Switching lever ............... 9, 10, 19
T
Thread ...................................... 10
Tubing diameter ....................... 30
Tubing length ........................... 30
V
Validation ................................. 26
Validation date ......................... 30
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Key features
- Versatile buret unit.
- Suitable for simple dosings or titrations.
- Integrated data chip for storing exchange unit and reagent specifications.
- Data can be read out and updated by a suitable instrument.
