I am using a Polyolefin Adhesive-Lined heat-shrink tubing to water-proof wire joints.
The method works well but I need to measure if the seal is truly water-proof. The datasheet provides a test method:
Prepare 3 test assemblies insulated with SCT-2 as follows: Construct a 2-wire to 2-wire inline splice in any suitable manner (crimped, soldered, twisted or welded). Splice an AWG 18 and an AWG 14 to an AWG 20 and AWG 14. Each wire shall be approximately 12 inches long. The wire insulation shall be cross-linked polyolefin and the conductor shall be bare copper. Shrink a 2-inch length of SCT-2 over the splice area with an appropriate heat gun. Apply heat until the SCT-2 is completely recovered on the splice and the adhesive liner flows at both ends. Allow the test assemblies to cool to room temperature and immerse them, except for the ends, in a 5% salt solution for 24 hours at room temperature. Apply 50 volts DC to the immersed specimens and measure the current leakage.
I do not understand how to measure the current leakage. I get it that the input current will be exactly equal to the output current if the seal is truly water-proof, but if the seal is not water-proof where else would the current flow anyway?