Agilent Technologies 4294A Operating Manual page 7

Caution
Do not exceed the operating input power, voltage, and current
level and signal type appropriate for the instrument being used, refer to
your instrument's Function Reference.
Electrostatic discharge(ESD) can damage the highly sensitive
microcircuits in your instrument. ESD damage is most likely to occur as
the test fixtures are being connected or disconnected. Protect them from
ESD damage by wearing a grounding strap that provides a high
resistance path to ground. Alternatively, ground yourself to discharge any
static charge built-up by touching the outer shell of any grounded
instrument chassis before touching the test port connectors..
4294A