A low voltage test is an electrical test with up to 33 VAC resp. 70 VDC. Typical applications are in their simplest version the open test and the short test. They are both part of a typical cable test.
While the open test should validate a set connection between two test points, the short test should detect unwanted connections between individual connections and/or single points.
Another option is the functional test, where the functioning of circuits and components is validated by using switching impulses.
No special safety circuit is necessarily needed in the low voltage test systems since they provide voltages below 33 VAC resp. 70 VDC, which are—following to DIN EN 61010—considered as non-hazardous.
The low voltage test needs to be distinguished from the high voltage test, whose job it is to verify insulation resistance and electric strength (HV-AC test, HV-DC test) resp. measure electric breakdown. Here it is mandatory to fulfil conditions of certain standards that define workplace safety and touchiness.