Reference Electrodes
Red Rod reference
electrodes
A reference electrode provides a stable potential
whatever the measurement conditions. The main
differences between reference electrodes are the
type of reference system and the liquid junction.
Radiometer Analytical offers electrodes using
both Red Rod and traditional technology
(calomel, silver-silver chloride, mercurous
sulphate and mercuric oxide).
103 mm
103 mm
20 mm
Electrodes with a double junction are mostly
designed for measurements using ion-selective
electrodes or samples sensitive to Cl – or K+.
103 mm
103 mm
Banana plug
Sleeve junctions have a high flow to prevent
the risk of clogging. Porous pins are used
for general applications. Fibre reference
electrodes have a slow flow to avoid
contamination of the media.
Applications
Reference system
Type
Part no.
Temperature range
Lower stem diameter
Liquid junction
Special features
Salt-bridge solution
Microsamples
Red Rod
REF200
E21M008
-10 – 100°C
4 mm
Porous pin
For use with
pHG200
Sat. KCl
Generalpurpose
Red Rod
Red Rod
REF201
REF251
E21M009
E21M001
-10 – 100°C
-10 – 100°C
7.5 mm
12 mm
Porous pin
Porous pin/
porous pin
Double
junction
Sat. KCl
Sat. KCl
Specialpurpose
Red Rod
REF261
E21M010
-10 – 100°C
12 mm
Glass sleeve
Sleeve
Sat. KCl
Reference electrodes
Obtaining accurate
and reproducible results:
some tips
120 mm
120 mm
120 mm
120 mm
120 mm
103 mm
103 mm
120 mm
120 mm
120 mm
80 mm
120 mm
103 mm
103 mm
103 mm
103 mm
160 mm
80 mm
120 mm
103 mm
BNC plug
103 mm
Banana plug
To ensure a stable reference potential,
the salt-bridge solution should not be more
than 5 mm below the electrode filling hole.
Top up when required.
Always read the proper storage conditions
described in the operating instructions.
Screw cap
Applications
Reference system
Type
Part no.
Temperature range
Lower diameter
Liquid junction
Connection
Salt-bridge solution
Generalpurpose
Ag/AgCl
REF321
E21M002
-5 – 80°C
8 mm
Porous pin
Non-aqueous Voltammetry Impedance
media
Ag/AgCl
Ag/AgCl
Ag/AgCl
REF361
XR300
XR820
E21M003
B20B300
B20C820
-5 – 80°C
-5 – 80°C
-5 – 80°C
12 mm
8 mm
8 mm
Glass sleeve
Porous pin
Porous pin/
fibre
Screw cap
BNC plug
Screw cap
Screw cap
shielded cable
3 M KCl
3 M KCl
Sat. KCl +
Sat. KCl + sat.
with sat. AgCl with sat. AgCl
sat. AgCl
AgCl upper res.
Special-purpose
Calomel
REF401*
E21M011
-10 – 60°C
7.5 mm
Porous pin
Calomel
REF421*
E21M004
-10 – 60°C
8 mm
Porous pin
Banana
plug
Sat. KCl
Screw cap
Sat. KCl
Calomel
REF451*
E21M005
-10 – 60°C
12 mm
Porous pin/
porous pin
Screw cap
Sat. KCl in
inner reservoir
Non-aqueous
media
Calomel
REF921*
E21M007
0 – 60°C
8 mm
Porous pin
Voltammetry
Chloride free
Calomel
XR100*
B20B100
-10 – 60°C
8 mm
Porous pin
Calomel
XR110*
B20B110
-10 – 60°C
8 mm
Porous pin
Calomel
XR130*
B20B130
-10 – 60°C
8 mm
Fibre
Calomel
XR150*
B20B150
-10 – 60°C
8 mm
Fibre
Screw cap
Screw cap
Screw cap
Screw cap
Screw cap
1 M LiCl
Sat. KCl
Sat. KCl
Sat. KCl
Sat. KCl
Voltammetry
Hg/Hg2SO4 Hg/Hg2SO4 Hg/Hg2SO4 Hg/Hg2SO4
REF601*
REF621*
XR200*
XR230*
E21M012
E21M006
B20B200
B20B230
0 – 60°C
0 – 60°C
0 – 60°C
0 – 60°C
7.5 mm
8 mm
8 mm
8 mm
Porous pin
Porous pin
Porous pin
Fibre
Banana
plug
Sat. K2SO4
Hg/HgO
XR400*
B20B400
0 – 60°C
8 mm
Porous pin
Hg/HgO
XR430*
B20B430
0 – 60°C
8 mm
Fibre
Hg/HgO
XR440*
B20B440
0 – 60°C
8 mm
Fibre
Screw cap
Screw cap
Screw cap
Screw cap
Screw cap
Screw cap
Sat. K2SO4
Sat. K2SO4
Sat. K2SO4
0.1 M KOH
1 M KOH
1 M KOH
Clean your electrodes regularly.
The operating instructions give details
of the most suitable cleaning procedure.
A correctly maintained reference electrode
has a lifetime of approximately 2 years.
* These Electrodes Contain Mercury.
Dispose According To Local, State Or
Federal Regulations.