Operation
PT12
Manual
7/20/2021
Page
26
of
48
4.4.2
CURRENT
MODE
For
each
probe,
the
PT12
supports
three
independently
selectable
current
modes,
1mA,
0.66mA,
and
0.33mA.
The
approximate
maximum
measurable
resistance
for
each
current
mode
is
listed
in
the
table
below:
Current
Mode
(mA)
Absolute
Maximum
Resistance
(
Ω
)
1
128
0.66
192
0.33
384
The
PT12
will
attempt
to
get
the
most
accurate
reading
possible
with
auto
current
mode
enabled.
It
attempts
to
use
the
most
suitable
current
depending
on
the
probe’s
resistance
and
the
range
of
the
reference
resistors
while
preventing
over/under
range
of
the
A/D
converter.
When
in
manual
current
mode,
it
is
possible
to
over
range
the
A/D
converter
if
the
probes
exceed
the
resistances
identified
in
the
table
above.
This
causes
no
harm
to
the
system
other
than
temporary
errant
readings.
If
the
resistance
of
the
probe
is
outside
the
range
of
the
PT12
internal
reference
resistors,
the
probe
readings
may
be
less
accurate.
Tap
the
current
mode
drop
‐
down
to
switch
between
auto
and
manual
current
modes.
If
manual
mode
is
selected,
a
secondary
drop
‐
down
appears
allowing
for
selection
of
1
mA,
0.66
mA,
and
0.33
mA.
Tap
the
save
button
to
ensure
the
values
persist
after
a
power
cycle.
Current
mode
is
saved
to
the
channel
only,
regardless
of
the
probe
type
(smart
or
basic).
