The test pens contain, similar to the test inks, fluids of defined surface tension. The surface energy of the material to be checked is determined simply by applying a stroke of ink with the tip of the felt pen. The accuracy of the measurement is, like the one of the test inks, 1mN/m
The test pens are available in a set of 8 pens from 30 to 44 mN/m.
On special demand also bigger or smaller values are available.
In case of proper handling we guarantee a shelf life of 6 months starting from the date of packaging. This is applicable to the test inks in the range from 29-72mN/m.
For our test inks 18.4-26mN/m and 76 - 105mN/m we guarantee a shelf life of 3 months.
The shelf life is dependant on usage and storage:
Discrepancies of +/- 1mN/m are standard.