Test Probe B (Test Finger Probe) to the action is used to simulate the human finger and palm, with its contact or if necessary to apply 10N force to contact the live parts of the device, in addition, in order to clearly determine whether the live parts are touched by the test finger, the test finger tail wire should also be connected to an output voltage of not less than 40V, but not greater than 50V electrical indicator, to display the test results. Judgment of test results: When using a live part of the test finger to disasso contact the appliance, the live part is touched if the indicator on the electrical indicator is on, and if the indicator is not on, the live part is not touched.

There are many standards that refer to Test Probe B, but the most original standards should be IEC 61032 and IEC 60529, which are one of the most important and commonly used test rods in laboratories such as electrical testing.

In addition, it is emphasized that the Test Probe B belongs to the IEC adult test finger, in addition, there are several kinds of children's test  finger, these are mentioned in the following article.