The 42842A is designed for use with the 42841A. It is connected directly to
the bias current output terminals of the 42841A. The following features ensure
accurate and safe DC bias measurements:
Clear plastic cover is provided for safe measurements.
Opening the cover decreases the voltage generated by back-e.m.f.
(electromotive force) to a level below 40 V within 0.1 second.
Heat-sensitive switch prevents DUT from overheating.