37.Lead in platinized platinum electrodes used for conductivity measurements where at least one of the following conditions applies:

1. (a)

   wide-range measurements with a conductivity range covering more than 1 order of magnitude (e.g. range between 0,1 mS/m and 5 mS/m) in laboratory applications for unknown concentrations;

2. (b)

   measurements of solutions where an accuracy of +/– 1 % of the sample range and where high corrosion resistance of the electrode are required for any of the following:

   1. (i)

      solutions with an acidity < pH 1;

   2. (ii)

      solutions with an alkalinity > pH 13;

   3. (iii)

      corrosive solutions containing halogen gas;

3. (c)

   measurements of conductivities above 100 mS/m that must be performed with portable instruments.

Expires on 31 December 2018.