Metrohm 6.00402.300 User manual

dAg ring electrode
6.00402.300
Sensor leaflet
8.0109.8008EN / 2021-09-23

Metrohm AG
Ionenstrasse
CH-9100 Herisau
Switzerland
[phone]
[email protected]
www.metrohm.com
dAg ring electrode
6.00402.300
Sensor leaflet
8.0109.8008EN /
2021-09-23

Technical Communication
Metrohm AG
CH-9100 Herisau
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.
Disclaimer
Deficiencies arising from circumstances that are not the responsibility of
Metrohm, such as improper storage or improper use, etc., are expressly
excluded from the warranty. Unauthorized modifications to the product
(e.g. conversions or attachments) exclude any liability on the part of the
manufacturer for resulting damage and its consequences. Instructions and
notes in the Metrohm product documentation must be strictly followed.
Otherwise, Metrohm's liability is excluded.

￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭ Table of contents
dAg ring electrode
￭￭￭￭￭￭￭￭ III
Table of contents
1 Overview 1
1.1 dAg ring electrode – Product description ........................... 1
1.2 dAg ring electrode – Overview ............................................ 1
2 Functional description 2
2.1 Ag metal electrode – Functional description ...................... 2
3 Delivery and packaging 3
3.1 Delivery .................................................................................. 3
3.2 Packaging .............................................................................. 3
3.3 Unpacking and checking the electrode .............................. 3
3.4 Storing the dAg ring electrode ............................................ 4
4 Installation 6
4.1 Preparing the dAg ring electrode ........................................ 6
4.2 Mounting the electrode ....................................................... 7
5 Maintenance 9
5.1 Metal electrode – Changing/refilling the electrolyte ......... 9
5.2 Assessing a metal electrode ................................................ 9
6 Troubleshooting 11
7 Electrode – Disposal 12
8 Technical specifications 13
8.1 Ambient conditions ............................................................ 13
8.2 Metal electrode – Dimensions ........................................... 13
8.3 Metal electrode – Housing ................................................. 13
8.4 Metal electrode – Connectors specifications ................... 13
8.5 dTrodes – Display specifications ........................................ 14
8.6 dAg ring electrode – Measurement specifications .......... 14

￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭ Overview
￭￭￭￭￭￭￭￭ 1
1 Overview
1.1 dAg ring electrode – Product description
The dAg ring electrode is a combined metal electrode for precipitation
titrations with alteration of the pH value. The dAg ring electrode is a
dTrode (digital electrode) for OMNIS.
1.2 dAg ring electrode – Overview
Figure 1 dAg ring electrode
1Protective cap 2Electrode head
3Filler opening 4Diaphragm
5Metal ring

Ag metal electrode – Functional description ￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭
2￭￭￭￭￭￭￭￭
2 Functional description
2.1 Ag metal electrode – Functional description
Ag metal electrodes have a bare metal surface that is exposed to the solu-
tion. If the sample solution contains ions of this metal, an equilibrium
develops on the surface of the metal that depends on the concentration
of the metal ions.
Metal ions are taken up by the metal surface and simultaneously released
into the solution. This concentration-dependent equilibrium is character-
ized by a corresponding potential (Galvani potential).

￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭ Delivery and packaging
￭￭￭￭￭￭￭￭ 3
3 Delivery and packaging
3.1 Delivery
Inspect the delivery immediately upon receipt:
￭Check the delivery against the delivery note to ensure completeness.
￭Check the product for damage.
￭If the delivery is incomplete or damaged, contact your regional Met-
rohm representative.
3.2 Packaging
The product and accessories are supplied in protective special packaging.
Keep this packaging to ensure safe transportation of the product. If a
transport locking device is present, keep this as well for future reuse.
3.3 Unpacking and checking the electrode
Required accessories:
￭Tool for fixed electrodes (included)
1Unpacking the electrode
Remove the electrode with storage vessel from the packaging.
2Removing the storage vessel
Figure 2 Releasing the electrode from the storage vessel

Storing the dAg ring electrode ￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭
4￭￭￭￭￭￭￭￭
￭Hold the electrode and storage vessel firmly in your hand so that
the electrode cannot slip away.
￭Position the tool between the storage vessel and SGJ sleeve.
￭Carefully push the tool to the side to release the electrode.
Do not tip the tool forwards!
NOTICE
Avoid applying excess pressure to the tool. Otherwise, the elec-
trode could be released too abruptly.
3Checking the electrode for proper function
￭Preparing the electrode:
Preparing the dAg ring electrode (see chapter 4.1, page 6)
￭Checking the electrode:
Assessing a metal electrode (see chapter 5.2, page 9)
NOTICE
Defective electrodes must be sent back for warranty processing
within two months (starting from the day of delivery).
3.4 Storing the dAg ring electrode
The electrode head must be stored as follows to protect it from water, sol-
vents, dust and mechanical influences:
1Screw the protective cap (1-1) onto the electrode head (1-2).
2Store the electrode in the storage vessel. When doing so, ensure that
the diaphragm (1-4) is immersed in the corresponding storage solu-
tion.
NOTICE
We recommend using the reference electrolyte as a storage solu-
tion.
3Close the filler opening (1-3).

￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭ Delivery and packaging
￭￭￭￭￭￭￭￭ 5
NOTICE
Always store the electrode in the storage solution.

Preparing the dAg ring electrode ￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭
6￭￭￭￭￭￭￭￭
4 Installation
4.1 Preparing the dAg ring electrode
1Filling with reference electrolyte
Open the closure of the filler opening (1-3) and, if necessary, fill ref-
erence electrolyte up to the filler opening.
2Cleaning the electrode
￭Rinse the electrode with distilled water.
￭If there is excess contamination on the metal ring, clean it with a
moist towel and toothpaste or with the polishing set
(6.2802.000).
￭If necessary, use a suitable solvent to degrease the electrode.
NOTICE
The electrode should be rinsed before each measurement.
Frequent abrasive cleaning is not recommended.
3Cleaning a diaphragm that is clogged with silver chloride
￭Close the filler opening (1-3).
￭Immerse the electrode in a concentrated ammonia solution or 7%
thiourea solution in 0.1 mol/L of HCl for approximately 2 hours.
￭Rinse the electrode with distilled water.
￭Refill with 1 mol/L of KNO3 as a reference electrolyte.
￭Immerse the electrode in 1 mol/L of KNO3 for several hours.
4Connecting the electrode
￭Unscrew the protective cap (1-1).
￭Position the cable connection on the electrode head such that the
slot in the cable connection is on the guide lug of the electrode
head.
￭Push the socket in the cable connection into the plug inside the
electrode head.

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￭￭￭￭￭￭￭￭ 7
￭Push the outer ring of the cable connection over the electrode
head.
Ensure that the guide lugs in the electrode head are in the
grooves of the cable connection.
￭Push the cable connection onto the electrode head until it stops
and rotate the outer ring until it snaps in place.
NOTICE
To remove the cable, first release the outer ring and then carefully
pull the cable connection from the electrode head.
When doing so, be sure not to pull on the cable itself but the cable
connector instead.
4.2 Mounting the electrode
The electrode must sit securely in the titration head.
NOTICE
For automatic procedures, ensure that the cables have enough room
to move.
During the titration, it is important that the solution is mixed well. The stir-
ring rate should be high enough to form a small vortex. If the stirring rate

Mounting the electrode ￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭
8￭￭￭￭￭￭￭￭
is too high, then air bubbles will be aspirated. These may result in incor-
rect measured values. If the stirring rate is too low, then the solution is
only mixed slowly and the reaction time or titration time increases accord-
ingly.
In order for the measurement to be taken in a well-mixed solution after
the addition of the titrant, the titration tip should be positioned where tur-
bulence is high. Furthermore, the distance between the addition of the
titrant and the electrode should be as large as possible. Therefore, take
into account the stirring direction (counterclockwise or clockwise) when
positioning the electrode and titration tip.
1
2
3
1
2
3
a) b)
Figure 3 Diagrams showing rod stirrer, electrode and titration tip dur-
ing a titration. a) clockwise stirring direction, b) counterclock-
wise stirring direction.
1Rod stirrer 2Electrode
3Titration tip

￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭ Maintenance
￭￭￭￭￭￭￭￭ 9
5 Maintenance
5.1 Metal electrode – Changing/refilling the electrolyte
1Open the filler opening.
2Use a plastic pipette to empty the electrode.
3Rinse the inside of the electrode with the new electrolyte.
4Fill the electrode with electrolyte up to the filler opening.
5Close the filler opening if the electrode is not used immediately.
6Immerse the electrode in electrolyte solution overnight.
Then, the electrode is ready for use again.
5.2 Assessing a metal electrode
Carrying out a standard titration
1Fill a 100-mL beaker with 50 mL of deionized water.
2Add 2 mL of hydrochloric acid (c=0.1 mol/L).
3While stirring this mixture, titrate it with silver nitrate (c=0.1 mol/L)
under the following conditions:
Method DET U
Dosing rate Max.
Signal drift 50 mV/min
Min. waiting time 0 s
Max. waiting time 26 s
Measuring point dis-
tance
4
Min. increment 10.0 µL

Assessing a metal electrode ￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭
10 ￭￭￭￭￭￭￭￭
Dosing rate Max.
Stop volume 3 mL
Stop EP 9
Filling rate Max.
EP criterion 5
EP recognition All
4Compare the measurement result with the following specifications:
￭Consumption (EP) [mL]:
1.95–2.05
￭Potential jump [mV]:
deltaU90–110% > 70 mV
￭Titration time [s]:
approx. 150
NOTICE
If the measurement result does not correspond to the specifica-
tions, clean the electrode and run the test again. If titration
times are excessive, the stirring rate and the arrangement of the
stirrer, pipetting tip and electrode should be checked.

￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭ Troubleshooting
￭￭￭￭￭￭￭￭ 11
6 Troubleshooting
Problem Cause Remedy
Slow response The Ag layer is passivated
by the deposition of silver
halide, silver sulfide and sil-
ver oxide.
Clean the metal ring with toothpaste or a pol-
ishing set (6.2802.000) or immerse the elec-
trode in concentrated NH3.

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12 ￭￭￭￭￭￭￭￭
7 Electrode – Disposal
This product is covered by European Directive, 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.
Proceed as follows to dispose of the electrode:
1Draining the electrolyte
Use a plastic pipette to remove the electrolyte from the electrode.
2Disposing of the electrolyte
Dispose of the electrolyte in accordance with the legal provisions.
3Disposing of the electrode
Put the electrode in electronic waste recycling.
More details about the disposal of your old product can be obtained from
your local authorities, from waste disposal companies or from your local
dealer.

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￭￭￭￭￭￭￭￭ 13
8 Technical specifications
8.1 Ambient conditions
Nominal function range +5 to +45 °C at
max. 80%
relative humidity, non-
condensing
Storage +5 to +45 °C
8.2 Metal electrode – Dimensions
Measurements
Shaft diameter 12 mm
Maximum installation length 125 mm
8.3 Metal electrode – Housing
Materials
Shaft material Glass
8.4 Metal electrode – Connectors specifications
Connector Metrohm plug-in head
Q

dTrodes – Display specifications ￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭
14 ￭￭￭￭￭￭￭￭
8.5 dTrodes – Display specifications
Status display LED green-red
8.6 dAg ring electrode – Measurement specifications
pH range 0–14
Temperature range 0–70 °C
Minimum immersion depth 20 mm