1. Metrosensor electrodes
Precision is not accidental, but brought about by
design!

2. 2

3. Table of contents
Which electrode for which application?
Electrode recommendations for pH measurement
6-7
6
How is a Metrosensor made? 78-79
3
Electrode recommendations for titration 7 Theoretical fundamentals 80-101
1. Fundamentals of potentiometry 80-
Electrode catalog 8-69 1.1. Measuring setup 80
iTrodes 8-9 1.2. From potential to ion concentration –
Separate pH electrodes 12-13 the Nernst equation 80-81
Electrodes for pH measurement 14-17 1.3. Measuring electrodes 82
Electrodes for pH titration 18-21 1.3.1. pH glass electrodes 82-86
Special electrodes for pH measurement/pH titration 22-25 1.3.2. Metal electrodes 86-88
Separate metal and carbon electrodes 28-29 1.3.3. Ion-selective electrodes 88-90
Titrodes 30-31 1.4. Reference electrodes 90
Combined metal electrodes 32-33 1.4.1. Silver/silver chloride reference system 90
Electrodes for voltammetry 34-37 1.4.2. Metrosensor «Long Life» reference system 91
Electrodes for Karl Fischer titration 38-41 1.4.3. Diaphragms 91-94
Ion-selective electrodes and accessories 44-47 1.4.4. Reference electrolytes and
Surfactant electrodes and accessories 48-51 bridge electrolytes 95
Reference electrodes 54-57 2. Fundamentals of conductometry 96-100
Conductometric measuring cells 60-65 2.1. General 96-99
Temperature sensors 66-67 2.2. Conductivity measurement in accordance
Sensors for photometry 68-69 with USP and Pharm. Europe (EP) 99-100
3. Temperature measurement 101
Accessories 71-77
Electrode components and other accessories 72-73 Appendix 102-106
Ion standards, buffer solutions, electrolytes 74-75 Technical specifications 102-106
Electrical connections 76-77

4. 4 Metrohm stands for 65 year’s experience in ion analysis
– why should you wrack your brains, when we've already
done the thinking for you?
Metrohm Application Bulletins – instructions that
are guaranteed to work.
Pharm PAC – the most important methods for the
Metrohm PACs (Potentiometric Analysis Collections) determination of pharmaceutical ingredients in
contain ready-to-use methods, which are right up to accordance with European and US pharmacopeias.
date and always in compliance with the respective stand-
ards and regulations. Wine PAC – the most important methods in wine
analysis.
Surf PAC – the most important methods in sur-
factant analysis. Plate PAC – the most important methods for the
analysis of galvanic baths.
Oil PAC – the most important methods for the
analysis of petroleum products. Food PAC – the most important methods in food
analysis.
Get your know-how from the market leader!
www.metrohm.com

5. Electrode catalog
The illustrations of the articles are, unless specified other-
wise, approximately in original size.
Materials abbreviations:
EP Epoxide
5
PCTFE Polychlortrifluoroethylene
Unless otherwise specified, all combined pH electrodes PE Polyethylene
are filled with the referenced electrolytes c(KCl) = 3 mol/L PEEK Polyetheretherketone
(Order number 6.2308.020). PMMA Polymethyl metacrylate
POM Polyoxymethylene
The abbreviation «LL reference system» stands for the PP Polypropylene
Metrosensor «Long Life» reference system. More detailed PTFE Polytetrafluoroethylene
information on this can be found in the theoretical PVC Polyvinyl chloride
section, Chapter 1.4.2.
«DJ» stands for «double junction». These electrodes are
equipped with a bridge electrolyte chamber; the bridge
electrolyte is replaceable, which means that it can be
adapted to suit the sample.
Detailed information concerning technical specifications
can be found in the appendix «Technical Specifications.»
The electrochemical parameters are specified for 25 °C,
the outflow rates with a hydrostatic pressure of a 10 cm
high water column. «Shaft length» refers to the length of
the electrode tip up to the lower edge of the electrode
plug-in head. The installation length is the length from
the electrode tip to the upper edge of the standard
ground joint. In the case of flexible SGJ sleeves, this cor-
responds to the length down to the electrolyte refill
opening below. All flexible SGJ sleeves have like their size
the standard ground joint 14/15.

6. Electrodes for pH measurement
6 Application
Universal
Details
Clear, aqueous solutions, pH 0...14
Electrode
Primatrode with NTC
Order number
6.0228.010
Page
14
Universal laboratory use, pH 0...14 Unitrode with Pt 1000 6.0258.600 16
Routine measurement in similar samples Ecotrode Gel with NTC 6.0221.600 14
pH 1...11
Water General (demineralized water, drinking Aquatrode Plus with Pt 1000 6.0257.000 16
water, process water, sea water, environ-
mental sector)
Waste water General Unitrode with Pt 1000 6.0258.600 16
Sewage containing sulfides Profitrode 6.0255.100 18
Soil samples General (aqueous suspensions) Flat-membrane pH electrode 6.0256.100 22
Agriculture Fertilizers Unitrode with Pt 1000 6.0258.600 16
Horticulture solutions containing proteins Porotrode 6.0235.200 22
Plant cultivation
Liquid manure Profitrode 6.0255.100 18
Small sample volumes, culture media Biotrode 6.0224.100 22
Nutrient solutions Viscotrode 6.0239.100 24
Food General Unitrode with Pt 1000 6.0258.600 16
Beverages Food containing proteins, beer Porotrode 6.0235.200 22
Semi-luxury arti- Bread, meat, cheese, dough (measurements Spearhead electrode 6.0226.100 22
cles semi-solid samples)
Fruit and vegetable juices, wine, spirits Unitrode with Pt 1000 6.0258.600 16
Drinking water Aquatrode Plus with Pt 1000 6.0257.000 16
Pharmaceuticals Creams, liquid formulations, medicinal syrup, Viscotrode 6.0239.100 24
Biological mouthwash solutions, raw materials monitor-
samples ing in accordance with pharmacopoeias
Dialysis solutions, urine Unitrode with Pt 1000 6.0258.600 16
Solutions containing proteins Porotrode 6.0235.200 22
Infusion solutions Aquatrode Plus with Pt 1000 6.0257.000 16
Small sample volumes, gastric juice, serum Biotrode 6.0224.100 22
Pilot plant measurements Syntrode with Pt 1000 6.0248.0X0 24
Cosmetics General (emulsions, shampoos, shower Viscotrode 6.0239.100 24
baths, liquid soaps, lotions, mouthwashes,
perfumes)
Skin (surfaces) Flat-membrane pH electrode 6.0256.100 22
Make-up Microelectrode 6.0234.100 24
Cleaning agents General (detergents, dishwashing liquids, Viscotrode 6.0239.100 24
Detergents cleaning agents, surfactant solutions)
Samples with pH values 10 Profitrode 6.0255.100 18
High-viscosity samples Unitrode with Pt 1000 6.0258.600 16
Leather Bleaching and dyeing baths, tanning liquors Profitrode 6.0255.100 18
Paper Fountain solution for offset printing, glue Unitrode with Pt 1000 6.0258.600 16
Textiles
Leather, paper, textiles (surface) Flat-membrane pH electrode 6.0256.100 22
Washing liquors Viscotrode 6.0239.100 24
Paints Stains (wood), dye baths, inks Profitrode 6.0255.100 18
Lacquers Dispersions, emulsions, resins, lacquers, Unitrode with Pt 1000 6.0258.600 16
Solvents suspensions
Paint coatings (surfaces) Flat-membrane pH electrode 6.0256.100 22
Non-aqueous, polar solvents EtOH-Trode 6.0269.100 16
Electroplating General (etching, pickling and degreasing baths, Profitrode 6.0255.100 18
Metal process- alkaline electroplating and phosphatizing
ing Acidic electroplating baths Unitrode with Pt 1000 6.0258.600 16
Drilling oil emulsions Viscotrode 6.0239.100 24
Special Measurements in semi-solid samples Spearhead electrode 6.0226.100 22
applications Solutions containing proteins Porotrode 6.0235.200 22
Samples with pH values 12 and tempera- Unitrode with Pt 1000 6.0258.600 16
tures 50...80 °C
Temperature 80...100 °C Unitrode with Pt 1000 reference 6.0258.600 16
electrolyte: Idrolyte
Ion-deficient, weakly buffered solutions Aquatrode Plus with Pt 1000 6.0257.000 16
Small sample volumes Biotrode 6.0224.100 22
Flat-membrane pH electrode 6.0256.100 22
Surface measurements Flat-membrane pH electrode 6.0256.100 22
Developer baths, concentrated acids Profitrode 6.0255.100 18
Emulsions/suspensions Unitrode with Pt 1000 6.0258.600 16
Fuels containing ethanol/E85 EtOH-Trode 6.0269.100 16

7. Electrodes for titration
Application
Aqueous
Details
General
Electrode
Ecotrode Plus
Order number
6.0262.100
Page
18
7
acid/base Routine measurement in similar samples Ecotrode Gel 6.0221.100 18
titrations
Alkaline samples, Bayer liquors Unitrode 6.0259.100 18
Titrations at high temperatures Unitrode with reference electro- 6.0259.100 18
lyte Idrolyte
Acid content of alcoholic beverages Unitrode with Pt 1000 6.0258.600 18
Titrations with small sample volumes Microelectrode 6.0234.100 24
Flat-membrane electrode 6.0256.100 22
Titrations in ion-deficient aqueous media Aquatrode Plus 6.0253.100 20
Carbonate hardness and acid capacity of Aquatrode Plus with Pt 1000 6.0257.000 16
water, p m values
Electroplating, etching and phosphatizing Profitrode 6.0255.100 18
Etching baths containing fluoride or Combined antimony electrode 6.0421.100 32
hydrofluoric acid
Samples containing protein Porotrode 6.0235.200 22
Non-aqueous Titrations with perchloric acid, cyclohexylamine, Solvotrode with c(LiCl) = 2 mol/L 6.0229.100 20
acid/base alcoholic HCl, determination of base number in ethanol
titrations (TBN) of crude oil products
Titrations with alcoholic KOH, NaOH and Solvotrode with c(TEABr) = 0.4 6.0229.100 20
TBAOH, potassium methylate, determination mol/L in ethylene glycol
of the total acid number (TAN) of petroleum
products, free fatty acid/hydroxyl number in
oils and fats
Redox titrations Titrations without change of the pH value Pt Titrode 6.0431.100 30
Titrants: Titrations with change of the pH value Combined LL-Pt ring electrode 6.0451.100 32
arsenite, cersulfate Chemical oxygen demand (COD) in waters Combined LL-Au ring electrode 6.0452.100 32
iron(III), iodine,
potassium bromate Penicillin, ampicillin Combined LL-Au ring electrode 6.0452.100 32
sodium nitrite Bromatometry, iodometry and cerimetry in Pt Titrode 6.0431.100 30
oxalic acid, perman- accordance with Pharm. Europe USP
ganate, thiosul-
fate, titanium(III),
Hg(NO3)2
Karl Fischer rea- Water determination according to Karl Double Pt wire electrode 6.0338.100 38
gent Fischer
Titrations in Double Pt wire electrode 6.0341.100 38
«Ipol» mode
Precipitation Chloride in general, sodium chloride content Ag Titrode 6.0430.100 30
titrations in foods
Titrants: Chloride in dialysis and infusion solutions Ag Titrode with Ag2S coating 6.0430.100 30
Silver nitrate
Titrations in accordance with Pharm. Europe USP Ag Titrode with Ag2S coating 6.0430.100 30
Determination of hydrogen sulfide, mer- Ag Titrode with Ag2S coating 6.0430.100 30
captans, carbonyl sulfides, sulfides
Chloride, bromide, iodide and cyanide in Ag Titrode with Ag2S coating 6.0430.100 30
electroplating baths
–
Fluoride/hydrofluoric acid in etching baths F -ISE – crystal membrane 6.0502.150 44
Complexometry Back titration of excess Ba2+ with EDTA 2+
Ca -ISE polymer membrane 6.0508.110 44
Titrants: 2+ 2+
Determination of Ca , Mg in aqueous Ca2+-ISE polymer membrane 6.0508.110 44
EDTA, solutions (in accordance with AB 125)
©
Complexon 2+
Determination of Al, Ba, Bi, Ca, Cd, Co, Fe, Cu -ISE crystal membrane 6.0502.140 44
III and IV
Mg, Ni, Pb, Zn
Photometric Color indicators such as xylene orange, N,N- Spectrosense 523 nm 6.5501.100 Titrino 68
titrations diethyl-1,4-phenylenediamine, phenol- 6.5501.200
phthalein, thorine, dichlorophenolindophenol Titrando, Titrino plus
Color indicators such as dimethylsulfonazo III, Spectrosense 610 nm 6.5501.110 Titrino 68
hydroxy naphthol blue, eriochrome black T, 6.5501.210
HHSNN, diphenylaminosulfonate, murexide Titrando, Titrino plus
Surfactants in Titration of anionic and cationic surfactants, Surfactrode Resistant 6.0507.130 48
non-aqueous titrations in chloroform, formulations con-
media taining oil such as cooling lubricants, drilling
Aromatic and and cutting oils, oil-containing shower baths,
aliphatic hydro- pH 10
carbons, ketones, Titration of anionic and cationic Surfactrode Refill 6.0507.140 48
gasoline, kerosene, surfactants, titration of surfactant formula-
dichloroethane and tions, washing powders, soaps, pH 10
trichloroethane
Surfactants in Titration of cationic surfactants «Cationic Surfactant» electrode 6.0507.150 48
aqueous media Titration of anionic surfactants «Ionic Surfactant» electrode 6.0507.120 48
Titration of non-ionic surfactants NIO electrode 6.0507.010 48
Titration of pharmaceutical ingredients with
sodium tetraphenylborate

8. iTrodes – The intelligent electrodes
8 The iTrodes
The iTrodes of the new intelligent electrode generation
854 iConnect – measuring input «on a chip»
The green color of Metrohm has always meant leading
confirm Metrohm’s longstanding leadership position in edge technology. Thanks to state-of-the-art electronics
the field of potentiometric titration. Metrohm reduces an entire measuring input down to the
size of a postage stamp. This means that the complete
The electrode used for the titration is the most important measuring input fits in the electrode cable head. It is
component of any titration system. But until now, the automatically recognized and identified by its serial
electrode, of all things, has represented the last gap in number.
traceability. The Titrando with iConnect closes this gap,
thus guaranteeing complete traceability of the analytic Digital data transmission
result to each component playing a role in the analysis. Directly in the sensor, the analog/dialog converter of the
latest generation in the 854 iConnect, converts the ana-
Digital identification – Mix-ups are eliminated log measuring signal into binary code. Digital data trans-
The built-in memory chip enables the storage of impor- mission means that the measuring signal is no longer
tant sensor data such as article number, serial number, susceptible to electrostatic influences. Interference-free
calibration data, calibration history, working life and transmission can now always be guaranteed, no matter
calibration validity period. how long the electrode cable is.
All of the sensor data are uploaded automatically when Just take the measuring input with you!
the iTrode is connected to the Titrando. This means that With 854 iConnect the sensor and measuring input are
the possibility of any mix-up or editing error is elimi- always calibrated together and the calibration data is
nated. stored in the intelligent electrode. As the measuring
input is no longer built into the instrument, the electrode
The electrode is identified automatically. The user is and 854 iConnect can be used together with different
informed if the electrode does not match the one titrators. The calibration procedure is no longer associ-
defined in the method. This means that it is not possible ated with a particular titrator.
to use an incorrect electrode.
iTrodes can be used with the 867 pH module or the 888
Storage of calibration data – no chance for outliers and 90x Titrandos.
Monitoring functions allow the exclusion of electrodes
whose calibration data lies outside the limits or whose
calibration period has already expired.
If the sensor is used on different instruments or if one
wishes to prevent inexperienced users from having to
calibrate the electrode on their own instruments, the
electrode can be calibrated on a different instrument
under defined conditions. The calibration data in the
memory chip make the electrode transferable; it thus
does not need to be recalibrated every time it is used
with a different instrument.

9. 9
Ordering information
iAquatrode Plus with Pt 1000 6.0277.300
iUnitrode with Pt 1000 6.0278.300
iSolvotrode 6.0279.300
iEcotrode plus 6.0280.300
iAg Titrode 6.0470.300
iAg Titrode with Ag2S coating 6.0470.300S
iPt Titrode 6.0471.300
iConnect 2.854.0010

10. 10

11. Electrodes for pH measurement/pH titration 11
Fine-tune your measurements!
The greatest precision and ease of care – these are the two outstanding properties of Unitrode and Aquatrode Plus.
The constant electrolyte outflow of the fixed ground joint diaphragm (which is largely insensitive to contamination)
guarantees a low-noise measuring signal, even in difficult samples and independent of the measuring conditions.
Further details can be found in the theoretical section on page 92.

12. Separate pH glass electrodes
12 Separate pH glass electrode
Electrically shielded
Technical specifications
pH range 0...14
Blue T glass for reliable results, e.g. in differential Temperature range 0...80 °C
potentiometry in non-aqueous media Installation length 142 mm
Optimal length for sample changer applications Shaft diameter 12 mm
Minimum immersion depth 15 mm
Electrode plug-in head Metrohm plug-in head G
Differential potentiometry
In addition to the measuring electrode, a reference electrode and an auxiliary electrode are required for differential
potentiometry. The shielding of the reference electrode must be identical to that of the measuring electrode.
Reference electrodes for differential potentiometry (see «Reference electrodes» section)
Ag/AgCl DJ reference electrode, length 125 mm, Metrohm plug-in head G
Without electrolyte filling, without cable 6.0729.100
Filled with LiClsat in ethanol, without cable 6.0729.108
Ag/AgCl DJ reference electrode, length 162 mm, Metrohm plug-in head G
Without electrolyte filling, without cable 6.0729.110
Auxiliary electrodes for differential potentiometry, Metrohm plug-in head B (see «Separate metal electrodes»
section)
Separate Pt wire electrode 6.0301.100
Separate Pt pin electrode 6.1241.040 + 6.1248.000
Separate Pt ring electrode 6.0351.100

13. 13
Ordering information
Separated pH glass electrode, without cable 6.0150.100

14. Electrodes for pH measurement
14 Primatrode with NTC – the economical entry to
GLP-compliant pH measurement
Technical specifications
Primatrode
For solutions that do not contain precipitates, pro- Shaft material PP
teins or sulfides pH range 0...14
Long-lasting standard electrode Temperature range 0...80 °C
Unbreakable plastic shaft Temperature sensor NTC
Impact protection for the glass membrane Diaphragm Ceramic pin
Fixed cable (length 1.2 m) Installation length 113 mm
LL reference system with long-term stability Shaft diameter 12 mm
Variant 6.0228.020 with waterproof plug I for use Minimum immersion depth 15 mm
with the 826 pH mobile (IP67)
The Solitrode with Pt 1000 – robust and reliable, Technical specifications
ideal for routine laboratory use Solitrode
For solutions that do not contain precipitates, proteins Shaft material PP
or sulfides pH range 0...14
Long-lasting standard electrode Temperature range 0...80 °C
Unbrekable plastic shaft Temperature sensor Pt 1000
Impact protection for the glass membrane Diaphragm Ceramic pin
Fixed cable (length 1.2 m) Installation length 113 mm
LL reference system with long-term stability Shaft diameter 12 mm
Minimum immersion depth 15 mm
Ecotrode Gel – the maintenance-free solution Technical specifications
Ideal for routine measurements in similar samples Ecotrode Gel
Maintenance-free Shaft material Glass
Life-time indicator pH range 1...11
LL reference system with long-term stability Temperature range 0...60 °C
Temperature sensor NTC
Diaphragm Twin pore
Installation length 125 mm
Shaft diameter 12 mm
Minimum immersion depth 20 mm
Electrode plug-in head Metrohm plug-in head U
How to store your electrodes correctly:
Rapid response is not a matter of magic, but rather a question of storage! Metrohm recommends the patented
6.2323.000 storage solution for all combined pH glass electrodes which use c(KCl) = 3 mol/L as the reference
electrolyte. This prevents the aging of the glass membrane and, as a result, guarantees response times short as they
were on the first day. More information on this can be found in the theoretical section in Chapter 1.3.1. «pH glass
electrodes.»

15. 15
Primatrode
The economical entry
to GLP-compliant pH
measurement
Solitrode
Robust and reliable, ideal
for routine
laboratory use
Ecotrode Gel
The maintenance-free
solution
Ordering information
Primatrode with NTC, fixed cable with plug F + 1 x 2 mm 6.0228.010
Primatrode with NTC, fixed cable with plug I (IP67) + 1 x 2 mm 6.0228.020
Solitrode without temperature sensor, without cable 6.0220.100
Solitrode with Pt 1000, fixed cable plug F + 2 x 4 mm 6.0228.000
Ecotrode Gel with NTC, without cable, plug-in head U 6.0221.600

16. Electrodes for pH measurement
16 Unitrode with Pt 1000 – high performance in
difficult samples and at high pH values
Technical specifications
Unitrode
For universal use, even in dyes, pigments, inks, suspen- Shaft material Glass
sions, resins and polymers pH range 0...14
Fixed ground-joint diaphragm insensitive to contamination Temperature range 0...100 °C
High temperature resistance and very low alkali error Temperature sensor Pt 1000
Rapid response to temperature changes Diaphragm Fixed ground joint
Outer electrolyte Idrolyte for temperatures of Installation length 113 mm
80...100 °C Shaft diameter 12 mm
Fixed cable (length 1.2 m) or with plug-in head U and Minimum immersion depth 25 mm
removable cable
LL reference system with long-term stability
Aquatrode Plus with Pt 1000 – ideal for weekly Technical specifications
buffered aqueous solutions Aquatrode Plus
Special electrode membrane glass: precise measuring Shaft material Glass
values and very rapid response times, even in weekly pH range 0...13
buffered solutions such as drinking water, surface Temperature range 0...60 °C
water and rain water and other poorly conducting Temperature sensor Pt 1000
solutions Diaphragm Fixed ground joint
Maintenance-free inner reference electrolyte (gel) Installation length 125/260 mm
Variable bridge electrolyte for special applications Shaft diameter 12 mm
Fixed ground joint diaphragm insensitive to contamination Minimum immersion depth 20 mm
Optimized length for sample changer applications
Fixed cable (length 2 m)
LL reference system with long-term stability
Technical specifications
EtOH-Trode – the specialist for ethanol EtOH-Trode
Developed for pHe measurement in ethanol Shaft material Glass
Special membrane glass pH range 0...12
Very precise ground joint diaphragm Temperature range 0...80 °C
Double-junction system for free choice of electrolytes Diaphragm Fixed ground joint
(e.g. 3 M KCI in ASTM D 6423, 1 M LiCI in EN Installation length 145 mm
15490). Shaft diameter 12 mm
LL reference system with long-term stability Minimum immersion depth 20 mm
Electrode plug-in head Metrohm plug-in head G
Wellness for the electrode
Reliable measuring results over long periods of time can only be guaranteed if the glass membrane and the dia-
phragm receive preventative and regular care. Cleaning by means of etching with toxic chemicals or a mechanical
treatment of the diaphragm is not only complicated and expensive, it also accelerates the aging of the pH glass
electrode as well. The 6.2325.000 care kit was developed for simple, gentle cleaning of pH glass electrodes with a
liquid electrolyte. Regular application can considerably prolong its lifetime.

17. 17
EtOH-Trode
The specialist for
pHe measurement
Unitrode
High performance, even in
difficult samples and at high
temperatures
Aquatrode Plus
Rapid response times
and greatest precision in
poorly buffered solutions due to
special electrode glass and fixed
ground joint diaphragm
Ordering information
Unitrode with Pt 1000, fixed cable plug F + 2 x B (4 mm) 6.0258.000
Unitrode with Pt 1000, fixed cable plug F + 2 x 2 mm 6.0258.010
Unitrode without temperature sensor, without cable 6.0259.100
Unitrode with Pt 1000, without cable, plug-in head U 6.0258.600
Aquatrode Plus without temperature sensor, length 125 mm, without cable 6.0253.100
Aquatrode Plus without temperature sensor, length 260 mm, without cable 6.0253.120
Aquatrode Plus with Pt 1000, length 125 mm, fixed cable plug F + 2 x B (4 mm) 6.0257.000
Aquatrode Plus with Pt 1000, length 260 mm, fixed cable plug F + 2 x B (4 mm) 6.0257.020
EtOH-Trode without temperature sensor, without cable 6.0269.100

18. Electrodes for pH titration
18 Ecotrode Gel – the maintenance-free solution
Ideal for routine measurements in similar samples
Technical specifications
Ecotrode Gel
Maintenance-free Shaft material Glass
Lifetime indicator pH range 1...11
LL reference system with long-term stability Temperature range 0...60 °C
Diaphragm Twin pore
Installation length 125 mm
Shaft diameter 12 mm
Minimum immersion depth 20 mm
Electrode plug-in head Metrohm plug-in head G
Ecotrode Plus – high durability in routine use at a Technical specifications
fair price Ecotrode Plus
For acid/base titrations in various kinds of solutions Shaft material Glass
Fixed ground joint diaphragm insensitive to contamination pH range 0...13
Ideal for routine laboratory use Temperature range 0...80 °C
LL reference system with long-term stability Diaphragm Fixed ground joint
Installation length 113 mm
Shaft diameter 12 mm
Minimum immersion depth 20 mm
Electrode plug-in head Metrohm plug-in head G
Profitrode – professional working in the most Technical specifications
difficult of matrices Profitrode
For difficult matrices (galvanic baths, precipitates, Shaft material Glass
samples containing sulfides, etc.) pH range 0...14
Flexible ground joint diaphragm, particularly easy to Temperature range 0...80 °C
clean Diaphragm Flexible ground joint
Double-junction construction Installation length 113/170/310 mm
Available in various lengths Shaft diameter 12 mm
(113/170/310 mm) Minimum immersion depth 30 mm
LL reference system with long-term stability Electrode plug-in head Metrohm plug-in head G
Unitrode – high performance in difficult samples Technical specifications
and at high pH values Unitrode
For universal use, even in dyes, pigments, inks, sus- Shaft material Glass
pensions, resins and polymers pH range 0...14
Fixed ground joint diaphragm insensitive to contamination Temperature range 0...100 °C
High temperature resistance and very low alkali error Diaphragm Fixed ground joint
Rapid response to temperature changes Installation length 113 mm
Outer electrolyte Idrolyte for temperatures of Shaft diameter 12 mm
80...100 °C Minimum immersion depth 25 mm
LL reference system with long-term stability

19. 19
Ecotrode Gel
Maintenance-free
pH measurement/
titration
Ecotrode Plus
High durability in routine
use at a fair price
Profitrode
Professional working in the
most difficult matrices
Unitrode
High performance in
difficult samples and
at high pH values
Ordering information
Ecotrode Gel without temperature sensor, without cable 6.0221.100
Ecotrode Plus, without cable 6.0262.100
Profitrode, length 113 mm, without cable 6.0255.100
Profitrode, length 170 mm, without cable 6.0255.110
Profitrode, length 310 mm, without cable 6.0255.120
Unitrode with Pt 1000, fixed cable plug F + 2 x B (4 mm) 6.0258.000
Unitrode with Pt 1000, fixed cable plug F + 2 x 2 mm 6.0258.010
Unitrode without temperature sensor, without cable 6.0259.100
Unitrode with Pt 1000, without cable, plug-in head U 6.0258.600

20. Electrodes for pH titration
20 Aquatrode Plus – ideal for aqueous, weekly
buffered solutions
Technical specifications
Aquatrode Plus
Precise measuring values and very rapid response Shaft material Glass
times in ion-deficient or weekly buffered solutions – pH range 0...13
such as drinking water, surface water and rain water Temperature range 0...60 °C
– thanks to special membrane glass and optimized, Diaphragm Fixed ground joint
fixed ground joint diaphragm insensitive to contamination Installation length 125/260 mm
Maintenance-free inner reference electrolyte (gel) Shaft diameter 12 mm
Variable bridge electrolyte for special applications Minimum immersion depth 20 mm
Optimized length for sample changer applications Electrode plug-in head Metrohm plug-in head G
LL reference system with long-term stability
Solvotrode – space-saving alternative for titration Technical specifications
in non-aqueous media Solvotrode
For non-aqueous titrations in the pharmaceutical sector Shaft material Glass
For determination of TAN/TBN in compliance with pH range 0...14
ASTM D4739, D2896 and D664 and DIN ISO 3771 Temperature range 0...70 °C
and DIN EN 12634 Diaphragm Flexible ground joint
Reference electrolyte: LiCl(sat) in ethanol Installation length 113 mm
Rapid response and stable measuring values in Shaft diameter 12 mm
organic solvents Minimum immersion depth 20 mm
Shielding against electrostatic effects Electrode plug-in head Metrohm plug-in head G
Flexible ground joint diaphragm, particularly easy to
clean
LL reference system with long-term stability
Drinking water analysis – Does it matter at which stirring rate titration is performed?
When stirring in ion-deficient solutions, streaming potentials occur at pH electrodes with ceramic pin diaphragms
which falsify measuring values. In the case of a SET titration, e.g. to a defined pH value, a considerable error can be
produced if an incorrect value is measured at the start or at the endpoint of the titration. See page 93 to find out
why you can forget about this problem when using the Aquatrode Plus.

21. 21
Solvotrode
Space-saving alternative
for titration in
non-aqueous media
Aquatrode Plus
Fast response and excellent pre-
cision in weekly buffered solu-
tions thanks to special membrane
glass and fixed ground joint
diaphragm
Ordering information
Solvotrode, without cable 6.0229.100
Aquatrode Plus without temperature sensor, length 125 mm, without cable 6.0253.100
Aquatrode Plus without temperature sensor, length 260 mm, without cable 6.0253.120
Aquatrode Plus with Pt 1000, length 125 mm, fixed cable plug F + 2 x B (4 mm) 6.0257.000
Aquatrode Plus with Pt 1000, length 260 mm, fixed cable plug F + 2 x B (4 mm) 6.0257.020

22. Special electrodes for pH measurement/pH titration
22 Biotrode – pH measurement in small volumes
Very low immersion depth and very small diameter of
Technical specifications
Biotrode
the electrode tip (3 mm), exceptionally suited to small Shaft material Glass
measuring vessels pH range 1...11
For protein-containing samples and solutions with Temperature range 0...60 °C
organic components Diaphragm Platinum wire
Very low electrolyte outflow (Idrolyte) Installation length 113 mm
LL reference system with long-term stability Shaft diameter 12 mm
Shaft diameter bottom 3 mm
Minimum immersion depth 7 mm
Electrode plug-in head Metrohm plug-in head G
Spearhead electrode – pH measurement in Technical specifications
semi-solid samples Spearhead electrode
Robust electrode tip for measurements in semi-solid Shaft material Glass
samples such as cheese, meat, fruits, etc. pH range 1...11
Maintenance-free reference electrolyte (gel) Temperature range 0...40 °C
Easy-to-clean diaphragm Diaphragm Twin pore
LL reference system with long-term stability Installation length 98 mm
Shaft diameter 12 mm
Shaft diameter bottom 6 mm
Minimum immersion depth 10 mm
Electrode plug-in head Metrohm plug-in head G
Flat-membrane electrode – pH measurement on Technical specifications
surfaces and in small sample volumes Flat-membrane electrode
For pH measurement on surfaces such as paper, textiles, Shaft material Glass
leather or soil samples (aqueous suspensions) pH range 0...14
Measurement/titration in small sample volumes Temperature range 0...80 °C
Completely made of glass with extremely fine- Diaphragm Fixed ground joint
grounded surface Installation length 125 mm
LL reference system with long-term stability Shaft diameter 12 mm
Minimum immersion depth 1 mm
Electrode plug-in head Metrohm plug-in head G
Porotrode – pH measurement in protein contain- Technical specifications
ing samples Porotrode
For pH measurement in very contaminated, protein- Shaft material Glass
containing or viscous samples pH range 0...14
Low-maintenance capillary diaphragm Temperature range 0...80 °C
Polymer electrolyte Porolyte for uniform electrolyte Diaphragm Ceramic capillaries
outflow Installation length 125 mm
LL reference system with long-term stability Shaft diameter 12 mm
Minimum immersion depth 20 mm
Electrode plug-in head Metrohm plug-in head G

23. 23
Biotrode
pH measurement
in small volumes
Spearhead electrode
pH measurement in
semi-solid samples
Flat-membrane electrode
pH measurement on surfaces
Porotrode
pH measurement in
protein-containing samples
Ordering information
Biotrode, without cable 6.0224.100
Spearhead pH glass electrode, without cable 6.0226.100
Flat-membrane pH glass electrode, without cable 6.0256.100
Porotrode, without cable 6.0235.200

24. Special electrodes for pH measurement/pH titration
24 Microelectrode – routine use with sample
changers and smal vials
Technical specifications
Microelectrode
For simple acid/base titrations in aqueous solutions Shaft material Glass
Available in various lengths (113/168 mm) pH range 0...14
LL reference system with long-term stability Temperature range 0...80 °C
Diaphragm Ceramic pin
Installation length 113/168 mm
Shaft diameter 12 mm
Shaft diameter bottom 6.4 mm
Minimum immersion depth 20 mm
Electrode plug-in head Metrohm plug-in head G
Viscotrode – universal application in viscous Technical specifications
media Viscotrode
For viscous protein- or sulfides- containing media Shaft material Glass
Flexible ground joint diaphragm, particularly easy to pH range 0...14
clean Temperature range 0...80 °C
LL reference system with long-term stability Diaphragm Flexible ground joint
Installation length 113 mm
Shaft diameter 12 mm
Minimum immersion depth 30 mm
Electrode plug-in head Metrohm plug-in head G
Syntrode with Pt 1000 – use in Technical specifications
synthesis and in bioreactors Syntrode
Low-maintenance thanks to storage vessel for Shaft material Glass
reference electrolytes pH range 0...14
Fixed ground joint diaphragm insensitive to Temperature range 0...100 °C
contamination Temperature sensor Pt 1000
High temperature resistance Diaphragm Fixed ground-joint
Available in various lengths (288/438 mm) Installation length 288/438 mm
Fixed cable (length 2/3 m) Shaft diameter 12 mm
LL reference system with long-term stability Minimum immersion depth 25 mm

25. 25
size
d in
uce
red
ion
trat
Illus
Microelectrode
Routine use with
sample changers
and small vials
Viscotrode
Universal use in
viscous media
Syntrode with Pt 1000
For use in synthesis
and in bioreactors
Ordering information
Microelectrode, length 113 mm, without cable 6.0234.100
Microelectrode, length 168 mm, without cable 6.0234.110
Viscotrode, without cable 6.0239.100
Syntrode with Pt 1000, length 288 mm, fixed cable 2 m, plug F + 2 x B (4 mm) 6.0248.020
Syntrode with Pt 1000, length 438 mm, fixed cable 3 m, plug F + 2 x B (4 mm) 6.0248.030

26. 26

27. Metal electrodes 27
High-performance metal electrodes for redox and precipitation titration, voltammetry and water determination
according to Karl Fischer.

28. Separate metal and carbon electrodes
28 Separate Pt-wire electrode
Electrode tip made of Pt-wire (0.8 x 6 mm)
Technical specifications
Separate Pt-wire electrode
Auxiliary electrode for differential potentiometry Shaft material Glass
Measuring range -2000...2000 mV
Temperature range -20...70 °C
Installation length 125 mm
Shaft diameter 12 mm
Minimum immersion depth 10 mm
Electrode plug-in head Metrohm plug-in head B
Separate double Pt-sheet electrode Technical specifications
For bivoltammetric titrations Separate double Pt-sheet electrode
For titration with conductometric endpoint recognition Shaft material Glass
Measuring range -2000...2000 mV
Temperature range -20...70 °C
Installation length 101 mm
Shaft diameter 12 mm
Minimum immersion depth 10 mm
Electrode plug-in head Metrohm plug-in head G
Separate metal-ring electrodes
Separate Ag-ring electrode Technical specifications
For precipitation titrations of halides, sulfides, Separate metal-ring electrodes
hydrogen sulfide, mercaptans and cyanides Shaft material Glass
Available with or without Ag2S coating Measuring range -2000...2000 mV
(specify when ordering) Temperature range -20...80 °C
Installation length 125 mm
Separate Pt-ring electrode Shaft diameter 12 mm
For all standard redox titrations Minimum immersion depth 7 mm
Electrode plug-in head Metrohm plug-in head G
Separate Au-ring electrode
For ferrometry (determination of the chemical oxygen
demand, COD)
For determination of penicillin and ampicillin
For titrations with Hg(NO3)2
For redox titrations in the presence of chromium or iron
Separate metal-rod electrodes
Consisting of separate electrode shaft made of PP Technical specifications
and exchangeable metal-rod (76 mm x 2 mm) made Separate metal-rod electrodes
of platinum, silver, gold, tungsten or glassy carbon Total length 162 mm
Installation length 140 mm
Degree of purity Shaft diameter 12 mm
Pt 99.90% Shaft diameter bottom 8 mm
Ag 99.99% Electrode plug-in head Metrohm plug-in head B
Gold 99.99%
W 99.95%

29. 29
Ordering information
Separate Pt-wire electrode 6.0301.100
Separate double Pt-sheet electrode 6.0309.100
Separate Ag-ring electrode 6.0350.100
Separate Pt-ring electrode 6.0351.100
Separate Au-ring electrode 6.0352.100
Shaft for separate meta-rod electrode 6.1241.040
Electrode rod Pt 6.1248.000
Electrode rod Ag 6.1248.010
Electrode rod Au 6.1248.030
Electrode rod glassy carbon 6.1248.040
Electrode rod W 6.1248.050

30. Titrodes – the maintenance-free metal electrodes
30 Pt Titrode / Pt Micro Titrode
For redox titrations without alteration of the pH value
Technical specifications
Titrodes
For bromatometry, iodometry and cerimetry in com- Shaft material Glass
pliance with Pharm. Europe USP Measuring range -2000...2000 mV
Maintenance-free reference system (pH glass pH range 0...14
membrane) Temperature range 0...80 °C
Reference system pH glass electrode
Ag Titrode / Ag Micro Titrode Installation length 125 mm
For precipitation titrations without alteration of the Shaft diameter 12 mm
pH value Minimum immersion depth 20 mm
For precipitation titrations of halides, sulfides, Electrode plug-in head Metrohm plug-in head G
hydrogen sulfide, mercaptans and cyanides
For titrations in compliance with Pharm. Europe USP Micro Titrodes
Available with or without Ag2S coating Shaft material Glass
(specify when ordering) Measuring range -2000...2000 mV
Maintenance-free reference system (pH glass pH range 0...14
membrane) Temperature range 0...80 °C
Reference system pH glass electrode
Au Micro Titrode Installation length 178 mm
For ferrometry (determination of the chemical oxygen Shaft diameter 12 mm
demand, COD) Shaft diameter bottom 6.4 mm
For the determination of penicillin and ampicillin Minimum immersion depth 20 mm
For titrations with Hg(NO3)2 Electrode plug-in head Metrohm plug-in head G
For redox titrations in the presence of chromium or iron
Maintenance-free reference system (pH glass
membrane)
Ag Titrodes: available with or without coating
Depending on the application (see application lists), the use of an Ag Titrode with or without Ag2S or AgBr coating
is recommended. We would be happy to supply you with your Ag Titrode with the respective coating at an addi-
tional charge; please specify when ordering.

31. 31
Titrodes
High performance in redox
and precipitation titrations
without alteration of the
pH value
Micro Titrodes
Optimized length and diameter
of the lower part of the
electrode for use in earlier
Metrohm sample changer
systems
Ordering information
Ag Titrode, without cable 6.0430.100
Ag Titrode, with Ag2S coating, without cable 6.0430.100S
Ag Titrode, with AgBr coating, without cable 6.0430.100Br
Pt Titrode, without cable 6.0431.100
Micro Ag Titrode, without cable 6.0433.110
Micro Pt Titrode, without cable 6.0434.110
Micro Au Titrode, without cable 6.0435.110

32. Combined metal electrodes
32 Combined Ag-ring electrode
For precipitation titrations of halides, sulfides,
Technical specifications
Combined Ag-ring electrode
hydrogen sulfide, mercaptans and cyanides with Shaft material Glass
alteration of the pH value Measuring range -2000...2000 mV
Available with or without Ag2S coating Temperature range -5...80 °C
(specify when ordering) Reference system Ag wire + AgCl
Reference electrolyte c(KNO3) = 1 mol/L
Combined Pt-ring electrode Diaphragm Ceramic pin
For redox titrations with alteration of the pH value Installation length 113 mm
Shaft diameter 12 mm
Combined Au-ring electrode Minimum immersion depth 15 mm
For ferrometry (determination of the chemical oxygen Electrode plug-in head Metrohm plug-in head G
demand COD)
For determination of penicillin and ampicillin Combined Pt-ring electrode / Au-ring electrode
Shaft material Glass
Measuring range -2000...2000 mV
Temperature range -5...80 °C
Reference system LL system
Reference electrolyte c(KCl) = 3 mol/L
Diaphragm Ceramic pin
Installation length 113 mm
Shaft diameter 12 mm
Minimum immersion depth 15 mm
Electrode plug-in head Metrohm plug-in head G
Combined Sb electrode Technical specifications
For pH titration in very hygroscopic matrices or in Combined Sb electrode
matrices containing hydrofluoric acid Shaft material PP
Unbreakable plastic shaft pH range 2...11
Temperature range 0...70 °C
Reference system LL system
Reference electrolyte c(KCl) = 3 mol/L
Diaphragm Ceramic pin
Installation length 113 mm
Shaft diameter 12 mm
Minimum immersion depth 15 mm
Electrode plug-in head Metrohm plug-in head G

33. 33
Combined metal-ring
electrodes
High performance with redox and
precipitation titrations with
alteration of the pH value
Combined
Sb electrode
pH titration in solutions con-
taining hydrofluoric acid
Ordering information
Combined Ag-ring electrode, without cable 6.0450.100
Combined Ag-ring electrode, with Ag2S coating, without cable 6.0450.100S
Combined Pt-ring electrode, without cable 6.0451.100
Combined Au-ring electrode, without cable 6.0452.100
Combined Sb-ring electrode, without cable 6.0421.100

34. Electrodes for voltammetry
34 The electrodes described in the following can be used in
various Metrohm voltammetry instruments: 663 VA
Stand, 694 VA Stand, 747 VA Stand, 757 VA Computrace
and 797 VA Computrace.
MME – Multi-Mode electrode Ordering information
Universally applicable working electrode for MME – Multi-Mode Electrode 6.1246.020
polarography and voltammetry Glass capillaries, not silanized, 10 units 6.1226.030
Determination of heavy metal ions, organic Glass capillaries, silanized, 10 units 6.1226.050
substances, anions
Determination range: ppm to ppt
Universal, robust, durable, easy maintenance,
no electrochemical conditioning required
Supplied without glass capillaries
Glass capillaries
Non-silanized glass capillaries
Standard capillary for polarography and stripping
voltammetry in alkaline solutions
For universal use with all pH values in aqueous and
non-aqueous solutions
Silanized glass capillaries
Silanized capillaries for stripping voltammetry in acidic
to mildly alkaline solutions
Stable drop formation in acidic or mildly alkaline
solutions (pH 10).
Applications with large mercury drops and/or long
accumulation times
Long lifetime

35. RDE – rotating disc electrodes
An RDE consists of a driving axle and an exchangeable
35
electrode tip.
Ordering information
Drive for rotating disc electrode (RDE) 6.1204.210
Drive for rotating disc electrode (RDE) 6.1204.220
with titanium axle and mercury contact
Stopper 6.2709.040
Electrode tips for the RDE
Order number Electrode tip Applications Determination range
6.1204.180 Ultratrace graphite Analysis of heavy metals with anodic ppb to ppt
stripping voltammetry (mercury film technique)
and with adsorptive stripping voltammetry
(without the use of mercury film)
6.1204.110 Glassy carbon Analysis of heavy metals with anodic ppb to ppt
stripping voltammetry (mercury film technique),
kinetic and thermodynamic studies
in electrochemistry
6.1204.120 Platinum Kinetic and thermodynamic ppm to ppt
Ø 2 mm unpolished studies in electrochemistry
6.1204.130 Silver Analysis of halogenides and pseudohalogenides ppb to ppt
6.1204.140 Gold Analysis of mercury and other metal ions ppb to ppt
with anodic stripping voltammetry
6.1204.150 Gold With laterally fitted electrode for arsenic ppb to ppt
determination with anodic stripping voltammetry
in compliance with Application Bulletin 226
6.1204.160 Platinum Analysis of organic additives in electroplating ppm to ppt
Ø 2 mm baths with cyclic voltammetric stripping
polished technique (CVS), kinetic and thermodynamic
studies in electrochemistry
6.1204.170 Platinum Analysis of organic additives in galvanic ppm to ppt
Ø 3 mm baths with cyclic voltammetric stripping
polished technique (CVS), kinetic and thermodynamic
studies in electrochemistry
6.1204.190 Platinum Analysis of organic additives in galvanic ppm to ppt
Ø 1 mm baths with cyclic voltammetric stripping
polished technique (CVS), kinetic and thermodynamic
shaft in glass studies in electrochemistry analysis
6.1204.610 Platinum Analysis of organic additives in electroplating ppm to ppt
Ø 2 mm baths with cyclic voltammetric stripping
polished technique (CVS), kinetic and thermodynamic
shaft in glass studies in electrochemistry

36. Electrodes for voltammetry
36 Reference electrode for Metrohm VA stands
Reference electrode made of plastic with ceramic Ordering information
diaphragm, filled
Universal double-junction reference electrode for Ag / AgCl reference electrode 6.0728.020
voltammetry Electrolyte vessel for Reference electrode 6.1245.010
Inner system filled with c(KCl) = 3 mol/L
Aqueous solutions, trace and ultra trace ranges, CVS
Low carry-over effects, low blank values
Reference electrode made of plastic with ceramic
diaphragm, dry
Double-junction reference electrode. Reference system dry Ag / AgCl reference electrode (dry) 6.0728.010
Studies in organic solvents with any electrolyte solution Electrolyte vessel for reference electrode 6.1245.010
Low carry-over effects, low blank values
LL reference electrode made of plastic with
ceramic diaphragm, filled
Double-junction reference electrode for the analysis LL-Ag/AgCl reference electrode 6.0728.030
of electroplating baths with cyclic voltammetric Electrolyte vessel for reference electrode 6.1245.010
stripping (CVS)
LL-Ag/AgCl (Gel) reference electrode 6.0728.040
Inner system filled with c(KCl) = 3 mol/L
Electrolyte vessel for reference electrode 6.1245.010
Very stable reference potential
LL reference electrode made of glass, filled
Double-junction reference electrode for the studies LL-Ag/AgCl (Gel) reference electrode 6.0730.000
of electroplating baths with cyclic voltammetric
stripping (CVS)
Very stable reference potential
Maintenance-free
Reference electrode made of glass with ground
joint diaphragm
Double-junction reference electrode with dry LL-Ag/AgCl(Gel) reference electrode glass 6.0728.000
reference system Electrolyte vessel for reference electrode 6.1245.010
For aqueous as well as non-aqueous solutions
Simple electrolyte replacement, low outflow rate
Auxiliary electrodes for Metrohm VA stands
Platinum auxiliary electrode
Universal auxiliary electrode for voltammetry Platinum auxiliary electrode 6.0343.000
For all applications with the MME as well as with the
rotating platinum disc electrode
Robust, easy maintenance
Glassy carbon auxiliary electrode
For all applications with rotating disc electrodes as Auxiliary electrode holder 6.1241.020
well as with the MME Glassy carbon rod 6.1247.000
Inert surface, no contamination of the measuring
cell by platinum

37. 6.1245.010
6.0728.010 + 6.0728.020
37
6.0728.000
6.0728.030
6.0728.040 6.1245.000
6.0730.000
6.0343.000
6.1241.020
6.1247.000
6.1204.3XX
Working electrodes for the Autolab RDE
Order number Electrode tip Applications Determination range
6.1204.300 Glassy carbon Analysis of heavy metals with anodic ppb to ppt
stripping voltammetry (mercury film technique),
kinetic and thermodynamic studies
in electrochemistry
6.1204.310 Platinum Kinetic and thermodynamic
studies in electrochemistry
6.1204.320 Gold Analysis of mercury and other metal ions ppm to ppt
with anodic stripping voltammetry
6.1204.330 Silver Analysis of halogenides and pseudohalogenides ppb to ppt

38. Electrodes for Karl Fischer titration
38 Double platinum-wire indicator electrodes
Indicator electrode for volumetric KF determination Technical specifications
For KFT equipment in the Titrino line, Titrandos and Measuring range -2000...2000 mV
Titro processors Temperature range -20...70 °C
For «Ipol»-mode titrations Installation length 96 mm
Also for 685 and 737 KF Coulometer Shaft diameter 8 mm
Minimum immersion depth 5 mm
Electrode plug-in head Metrohm plug-in head G
Indicator electrode for 756 and 831 KF Technical specifications
coulometer and 851 and 852 Titrandos Measuring range -2000...2000 mV
With standard ground joint 14/15 Temperature range -20...70 °C
Installation length 101 mm
Shaft diameter 12 mm
Shaft diameter bottom 8.75 mm
Minimum immersion depth 10 mm
Electrode plug-in head Metrohm plug-in head G
Indicator electrode for KF Sample Changers Technical specifications
Fixed cable (length 2 m with plug F) Measuring range -2000...2000 mV
Temperature range -20...70 °C
Installation length 103 mm
Shaft diameter 5.3 mm
Minimum immersion depth 10 mm

39. 39
Ordering information
Indicator electrode for 684 + 737 KF Coulometers 6.0338.100
Indicator electrode for 756 + 831 KF Coulometers 6.0341.100
Indicator electrode for 814 + 815 KF Sample Changers 6.0340.000

40. Electrodes for Karl Fischer titration
40 Generator electrodes
Generator electrode with diaphragm Technical specifications
for 684 + 737 KF Coulometers Temperature range -20...70 °C
Fixed cable (length 1 m, plug H) Installation length 65 mm
Shaft diameter 24 mm
Minimum immersion depth 15 mm
Generator electrode without diaphragm Technical specifications
for 684 + 737 KF Coulometers Temperature range -20...70 °C
Standard ground joint 29/22 and Metrohm plug-in Installation length 110 mm
head G Shaft diameter 24 mm
Requires cable 6.2104.120 for connection with KF Minimum immersion depth 15 mm
Coulometers
Generator electrode with diaphragm for 756 + Technical specifications
831 KF Coulometers and 851 + 852 Titrandos Temperature range -20...70 °C
Standard ground joint 29/22 and Metrohm plug-in Installation length 100 mm
head G Shaft diameter 24 mm
Requires cable 6.2104.120 for connection with KF Minimum immersion depth 15 mm
Coulometers
Generator electrode without diaphragm for 756 + Technical specifications
831 KF Coulometers and 851 + 852 Titrandos Temperature range -20...70 °C
Standard ground joint 29/22 and Metrohm plug-in Installation length 100 mm
head G Shaft diameter 24 mm
Requires cable 6.2104.120 for connection with KF Minimum immersion depth 15 mm
Coulometers

41. 41
6.0339.000
6.0342.110
Illustrations reduced in size
6.0344.100
6.0345.100
Ordering information
Generator electrode with diaphragm for 684 + 737 KF Coulometers 6.0339.000
Generator electrode without diaphragm for 684 + 737 KF Coulometers 6.0342.110
Generator electrode with diaphragm for 756 + 831 KF Coulometers 6.0344.100
and 851 + 852 Titrandos
Generator electrode without diaphragm for 756 + 831 KF Coulometers 6.0345.100
and 851 + 852 Titrandos

42. 42

43. 43
Electrodes for ion and surfactant analysis

44. Ion-selective electrodes
44 Polymer-membrane electrodes with replaceable
electrode tip for K+ and NO3–
Robust construction
High selectivity due to ionophores immobilized in the
membrane
Short preparation time after conditioning in a
standard solution
For aqueous solutions
Crystal-membrane electrodes
Robust construction
Can also be used for brief periods in organic solvents
Simple cleaning and renewal of electrode surface
with polishing set
Sodium-selective glass membrane electrode
For sodium determination in simple aqueous media
Polymer-membrane electrodes for Na+ and Ca2+
Robust construction
High selectivity due to ionophores immobilized in the
membrane
Short preparation time after conditioning in a
standard solution
For aqueous solutions
Ammonia-selective gas-membrane electrode
Robust construction
Short preparation time after conditioning in a
standard solution
The gas-permeable Teflon membrane ensures high
selectivity and prevents interferences by the measur-
ing solution
Rapid exchange of Teflon membrane thanks to
ready-for-use certified membrane modules

45. 45
Ion Article no. Membrane Min. Installation- Shaft- Tempera- Measure- pH range
material immersion length diameter ture range ment range
depth (mm) (mm) (mm) (°C) (mol/L)
Ag+ 6.0502.180 Crystal 1 123 12 0...80 10–7...1 2...8
Br– 6.0502.100 Crystal 1 123 12 0...50 5*10–6...1 0...14
Ca2+ 6.0508.110 Polymer 1 123 12 0...40 5*10–7...1 2...12
Cd2+ 6.0502.110 Crystal 1 123 12 0...80 10–7...10–1 2...12
Cl– 6.0502.120 Crystal 1 123 12 0...50 5*10–5...1 0...14
CN– 6.0502.130 Crystal 1 123 12 0...80 8*10–6...10–2 10...14
Cu2+ 6.0502.140 Crystal 1 123 12 0...80 10–8...10–1 2...12
F– 6.0502.150 Crystal 1 123 12 0...80 10–6...sat. 5...7
I– 6.0502.160 Crystal 1 123 12 0...50 5*10–8...1 0...14
K+ 6.0504.110 Polymer1 1 123 12 0...40 10–6...1 2.5...11
Na+ 6.0501.100 Glass 15 863 12 0...80 10–5...1 5...9
Na+ 6.0508.100 Polymer 1 123 12 0...40 10–6...1 3...12
NH4+ 6.0506.100 Gas membrane 1 123 12 0...50 5*10–7...1 11
NO3– 6.0504.120 Polymer1 1 123 12 0...40 7*10–6...1 2.5...11
Pb2+ 6.0502.170 Crystal 1 123 12 0...80 10–6...10–1 4...7
S2– 6.0502.180 Crystal 1 123 12 0...80 10–7...1 2...12
SCN– 6.0502.190 Crystal 1 123 12 0...50 5*10–6...1 2...10
1
Electrode with exchangeable electrode tip
2
Electrode shaft 6.1241.050 and electrode tip 6.1205.040 must be ordered separately.
3
Up to standard ground joint

46. Accessories for ion-selective electrodes
46 LL ISE reference, without cable 6.0750.100
Double-junction Ag/AgCl reference electrode with fixed
LL ISE Reference
A stable, reproducible reference potential is very impor-
ground-joint diaphragm and optimized length for sample tant at low ion concentrations, low ionic strengths and
changer applications. Standard bridge electrolyte: especially with repeated determinations using sample
c(KCl) = 3 mol/L. changer systems. For this reason Metrohm recom-
mends reference electrodes with a fixed ground-joint
diaphragm for working with ion-selective electrodes. In
addition to a constant electrolyte outflow of approx.
5...30 μL/h, these electrodes are also considerably less
influenced by either the ionic strength of the sample
solution or the stirring speed than other types of refer-
ence electrodes.
Polymer-membrane electrodes with
exchangeable electrode tip
6.1241.050 Electrode shaft for polymer-
membrane electrodes 6.0504.XXX
6.1205.020 Polymer-membrane electrode tip K+
Illustration reduced in size
6.1205.030 Polymer-membrane electrode tip NO3–
6.1255.000 Membrane module kit for 6.0506.100,
consisting of 3 membrane modules
+ 50 mL inner electrolyte
Other accessories
6.2802.000 Polishing set for crystal-membrane
electrodes 6.0502.1X0
Illustration reduced in size
(approx. 2 g AI2O3 and polishing cloth)
Ion standards (250 mL each), c(Ion) =
0.1000 ± 0.0005 mol/L (traceable to NIST)
KBr 6.2301.000
NaCl 6.2301.010
Cu(NO3)2 6.2301.020
NaF 6.2301.030
KI 6.2301.040
KCl 6.2301.060
CaCl2 6.2301.070
KNO3 6.2301.080
Pb ion standard 1.000 g/L ± 0.5% (250 mL)
Pb (1.000 g/L) 6.2301.100

47. 47
Spoilt for choice!
To what must I pay particular attention in an ion determination? Precision? Time needed? Costs?
Which method is the most suitable for my application? Titration? Direct measurement? Standard addition?
ISA? TISAB? When is their use advisable? Which solution do I need for my application? You will find the answers to
these questions along with many other useful tips for ion determination with ion-selective electrodes from Metrohm
in the theoretical part in section 1.3.3. «Ion-selective electrodes.»