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TEST INSTRUMENT SAFETY
(continued from inside front cover)
6. Some equipment with a two-wire ac power cord, including some with polarized power plugs, is the “hot chassis” type. This
includes most recent television receivers and audio equipment. A plastic or wooden cabinet insulates the chassis to protect the
customer. When the cabinet is removed for servicing, a serious shock hazard exists if the chassis is touched. Not only does this
present a dangerous shock hazard, but damage to test instruments or the equipment under test may result from connecting the
ground lead of most test instruments to a “hot chassis”. To test “hot chassis” equipment, alway s connect an isolation transformer
between the ac outlet and the equipment under test. The B+K Precision Model TR-110 or 1604 Isolation Transformer, or Model
1653 or 1655 AC Power Supply is suitable for most applications. To be on the safe side, treat all two-wire ac equipment as “hot-
chassis” unless you are sure it has an isolated chassis or an earth ground chassis.
7. On test instruments or any equipment with a 3-wire ac power plug, use only a 3-wire outlet. This is a safety feature to keep the
housing or other exposed elements at earth ground.
8. B+K Precision products are not authorized for use in any application involving direct contact between our product and the human
body, or for use as a critical component in a life support device or system. Here, “direct contact” refers to any connection from or
to our equipment via any cabling or switching means. A “critical component” is any component of a life support device or system
whose failure to perform can be reasonably expected to cause failure of that device or system, or to affect its safety or
effectiveness.
9. Never work alone. Someone should be nearby to render aid if necessary. Training in CPR (cardio-pulmonary resuscitation) first
aid is highly recommended.