9
TEST TECHNIQUES AND APPLICATIONS
TESTING USING DH4-C DUPLEX HANDSPIKES
Each handspike is marked with the letter P. This indicates the potential
terminals. These should be the ‘inside’ contacts when making a
measurement. One of the specially designed in-line test lead connectors is
fitted with two lamps marked L1 and L2 and an extra lead. This lead should
be plugged into the 4 mm socket labelled next to the P2 terminal. These
lamps provide information to the operator that would otherwise only be
available on the instrument display. The meaning of these lamps is described
below.
For example, using the in-line connecting test leads with the DLRO10HD in
one of the AUTO test modes:
1. Press the TEST button on the instrument.
2. Lamp L1 will illuminate a continuous red to indicate contact failure.
3. When all four contacts connect, L1 will extinguish.
4. No lamps will show during the test unless contact fails.
5. Lamp L2 will light a continuous green when current flow has decayed
to less that 1 mA to signal end of test.
6. Removing the probes will extinguish the green L2 (end of test) and
7. Light the red L1 (no contact).
Since your DLRO10HD always ensures good contact before applying the full
test current, when using the DH4-C test leads, there should be no erosion of
the contact tips. However, if the tips become worn or blunted, they can be
simply replaced by pulling out the worn tips and inserting new ones.
TESTING USING DUPLEX HANDSPIKES OR
INDIVIDUAL LEADS
Connect the four leads as shown. In all cases ensure that the potential
probes (P1 & P2) are inside the current (C1 & C2) probes
In-line connector with indicator lamps when
used with DLRO10HD
Lamp L1
Lamp L2
Meaning
Red
Off
Inadequate continuity at C
or
P
contacts
Flashing Red
Off
Voltage present between
contacts
Off
Green
Current , 1mA, test
Complete
Off
Red
Measurement
fail