The Megger® WM6 tester is a self-contained instrument
designed to give rapid and accurate resistance
measurements. The hand-operated generator is coupled
with the latest electronic technology, thus allowing the
WM6 to test insulation at 500 V d.c. up to 200 Mohms.
A low-voltage, hand-cranked, a.c. brushless generator,
which is easy to turn by hand, is the power source. It is
connected to a stabilized electronic invertor to provide the
test voltage. All resistance readings are given directly on a
moving-coil meter with a rugged taut-band suspension
movement, a white-on-black scale and an orange
“dayglow” pointer. This gives goodlegibility in most
lighting conditions.An electronic circuit is used to give a
four-decade resistance scale for insulation measurement.
There is a slider switch for selection of either the
insulation resistance or continuity functions, and the strong
ABS plastic case has a recess to accommodate the foldedaway
generator handle for compactness. Two 4-mm
terminal sockets are fitted into the side of the case for
connecting the test leads.