Key Features And Benefits - Extech Instruments 7470 Operation Manual

(MD). The instrument has five different MD circuits, selectable through the menu,
which are representative circuits designed to simulate the impedance of the human
body under different conditions. The impedance of the human body will vary
depending upon point of contact, the surface area of the contact and the path the
current flows. For these reasons, the specifications of the Measuring Devices are
different depending upon the type of test being performed as well as the maximum
allowable leakage current. Leakage current measurements are performed on
products under normal conditions and single fault conditions as well as reversed
polarity. This simulates possible problems, which could occur if the product under test
is faulted or misused while the product is operating under high line conditions (110% of
the highest input voltage rating of the product).
Line Leakage tests are normally specified as "Type Tests" or "Design Tests" which are
performed during the development of the product. This helps verify that the design is
safe but it does not guarantee the safety of the products being produced on the
production line. The only way to be sure you are shipping safe products is to test each
product at the end of the production line. The user may perform a Leakage Current
test along with other common safety test such as Dielectric Withstand, Insulation
Resistance, and Ground Bond on the production line with a single connection to the
device under test.

1.7. Key Features and Benefits:

Patented SmartGFI®
Storage of up to 50 setups
RS-232 or GPIB interfaces
Line and Load regulation
Digitally controlled arc
detection system
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The SmartGFI provides maximum operator
protection. If the circuit detects excessive leakage
to ground it shuts down the high voltage in less
than 1 millisecond. SmartGFI is automatically
activated if the DUT is not grounded. The operator
does not need to make the decision whether to
activate the SmartGFI.
A real benefit for manufacturers that test different
products. The instrument can store 50 individual
memories that may be performed individually or
connected for a 50-step test.
All the functions of the instruments can be
programmed over a RS-232, GPIB or printer
interface which makes them adaptable to any
automated production environment.
Maintains the output voltage to within 1% of setting
even if the load or the line voltage varies. This
ensures that the test results remain consistent and
within safety agency requirements.
Allows the operator to select whether low-level
arcs should be detected and provides the operator
with the ability to digitally select and program