OPERATION
2-12
CONNECTING A DEVICE
The SR715/720 has a built in Kelvin fixture for measuring radial leaded components and adapters for
measuring axial leaded components. The fixture provides a 4-wire Kelvin connection to the device under test
to minimize stray impedances that cause measurement errors. Most components will fit into this fixture, thus
eliminating the need for special fixtures.
Remember, whenever the fixture configuration is changed, open
and short circuit calibrations should be performed before making measurements.
Open and short circuit
calibration values are stored in non-volatile memory with the [Store] and [Recall] keys along with the complete
instrument setup. This allows compensation values for different fixtures to be stored then recalled whenever
different measurement setups are required. Also remember that when measurements are in progress, keep
hands or any other objects away from the fixture because the measurement accuracy may be affected. There
is a cover beneath the fixture to catch any leads that might fall through the fixture. For information on removing
leads or general maintenance to the fixture in general, refer to the Maintenance section.
RADIAL LEADED PARTS
To measure parts with radial leads, (leads coming out the same side of the
package) first remove any adapters or parts from the fixture, since they will
interfere with making a Kelvin connection. Next, make sure the leads are
reasonably clean of wax or other coatings. These can cause an unreliable contact
and gradually build up in the fixture. Insert one lead into each side of the fixture,
approximately centered and make the measurement.
AXIAL LEADED PARTS
To measure parts with axial leads, (leads coming out opposite ends of the
package) first remove any parts from the fixture. Install the axial adapters in the
center of each fixture half and slide them apart or together so the DUT will be
approximately centered in the fixture. Check that the leads are reasonably clean
and insert one lead in each side of the fixture adapter. After removing the axial
lead adapters, replace them in the two storage slots behind the fixture so as not
to misplace them.
Radial Fixture (with part)
Axial Fixture (with part)
