COMMISSION ON ELECTROANALYTICAL CHEMISTRY (V.5)
Number: 550/60/97
Title: Molality-Based Primary Standards for Electrolytic Conductivity
Coordinator(s): Kenneth
W. Pratt
Remarks: I.3, OIML
Completion Date: 2001 - project completed
Objective:
The project summarizes recent high accuracy absolute
measurements of the electrolytic conductivity of aqueous KCl solutions
of known molalities. The existing primary standards of the OIML for
the electrolytic conductivity were originally determined in the 1930s.
Since that time, the temperature and resistances scales and the atomic
weights of K and Cl have all changed. Furthermore, the current OIML
recommended values are referred to the non-customary "demal" unit of
concentration, defined only at specific concentrations. These factors
make desirable to replace the current OIML values with new recommended
values, based on absolute measurements using the current basic standards
and the ITS-90 temperature scale.
Progress:
A first draft has been already presented in Geneva. A revised manuscript
was approved by Commission V.5 at the Berlin meeting (August 1999) and
forwarded by Dr. W. Kutner (Secretary, Commission V.5) to Dr. D. S.
Moore (Secretary, IUPAC Analytical Chemistry Division).
Project completed - IUPAC Technical Report is in press in Pure
Appl. Chem.
73(11), pp. 1783-1793, 2001.
Last Update: 19 February 2002