Hach-Lange TITRALAB 840_845 Reference Manual - Manual (Page 131)

Titra Lab ® TitraLab 840 and 845 Reference Manual
Page 131
Potential versus
SHE This parameter is available when creating a reference or a combined
electrode with the option From = Other.
Refer to "Create electrode", page 66 .
This parameter enables you to calibrate electrodes with automatic
buffer checking using any kind of reference electrodes (for example
with a mercurous sulphate electrode Hg/Hg2SO4 (Sat. K2SO4)). You
just need to know the potential of the reference electrode versus the
Standard Hydrogen Electrode.
This potential is taken into account in the buffer recognition algorithm
and for pH calculation when no calibration is performed. When you
create a reference or a combined electrode with the option From =
Catalogue, the instrument calculates pH using the potential
versus SHE stored in memory for the reference electrode selected. In
this case, potential versus SHE cannot be changed.
The table below gives the potential at 25°C versus the SHE (E SHE)
of a few "reference elements/filling solution" couples.
Table 8: Reference electrode potentials versus SHE
Range available:
0.0 mV to +1000.0 mV
Reference element and filling
solution
E SHE
(mV)
Radiometer Analytical
Reference electrodes
Hg/Hg
2
Cl
2
– Sat. KCl
SCE: Saturated Calomel Electrode
+244 pHC4000, pHC4001, pHC4006,
XC601, REF401, REF421, REF451,
XR100, XR110, XR130, XR150,
MC408PtREF401, REF421, PHC4000
Hg/Hg
2
Cl
2
– 1M LiCl +280 REF921
Hg/Hg
2
SO
4
- Saturated K
2
SO
4
+651 REF601, REF621, XR200, XR230,
MC602Pt, MC6091Ag
Hg/Hg
2
SO
4
- 1 M H
2
SO
4
+616
Hg/HgO - 0.1 M KOH +174 XR400, XR430, XR440
Ag/AgCl - Saturated KCl +199 XR300, XR820, XC100, XC111,
XC120, XC161, XC200, XC250
Ag/AgCl - 3 M KCl +208 pHC3001, pHC3005, pHC3006,
pHC3011, pHC3081, pHC3185,
REF321, REF361, MC3051Pt,
ISEC301F
Ag/AgCl - 1 M KCl +235
Ag/AgCl - 0.6 M KCl (sea water) +250
Red Rod - Saturated KCl +199 pHC2001, pHC2002, pHC2003,
pHC2005, pHC2011, pHC2015,
pHC2051, pHC2085, pHC2401,
pHC2441, pHC2501, pHC2601,
pHC2701, REF200, REF201, REF251,
REF261, MC2095Sb,MC201Au-8