We have long advocated using a nickel under the cap of the pH storage solution container when using a pH sensor. The nickel acts as a lid to prevent spills, should the container be knocked over. However, in 2024 the manufacturer of the storage containers changed the design slightly, so that nickels are now too thick. We have created a 3D printable “thin nickel” to serve as a lid.

You can access the design on Tinkercad or Thingiverse.

The dimensions of these disks are: diameter = 21.20 mm, thickness = 0.80 mm