Dc Voltage; Ohms Calibration - Datron 1062 Service Handbook

4
1.3
OHMS
CALIBRATION
1.3.1
General
The
procedure
in
the table
opposite
is
all
that
is
necessary to
completely
'AUTOCAL'
the
Ohms
function.
If
just
the
Ohms
or
just
one range of the
Ohms
is
to
be
calibrated,
then steps
1
and 2
in
the
DC
Voltage Calibration
table
should be
carried
out
first.
Then on
each
Ohms
range
just a 'Zero'
and 'Gain' calibration
is
required.
If
the
'DVM
Reading After Calibration'
is
not
in
accordance with the
table,
repeat operations of the
same
'CALIBRATE'
key
is
permissible to
improve
the reading.
Where
no tolerance
is
shown
in
this
column, only the exact
reading
quoted with an occasional
least
significant digit
showing
is
to
be expected.
1.3.2 'Zero' Resistance
Source
For accurate 'Zero' calibration
on
Ohms
it is
ESSENTIAL
that
a
correctly
connected
zero source
is
used.
Two
arrangements are necessary as
shown
in
Fig. 1.1;
it
can be seen that
'4
wire
J2'
selection
is
recommended on
all
ranges.
1.3.3
Equipment Required
A
set of resistance
standards
from
lOfil
to
lOMO
in
decades;
it is
essential
that 10J2 to
lOOkfi standards are
4 terminal devices,
e.g.
Datron
4000/4000A
Autocal
Standard with Option
20.
1.3.4
Checking Accuracy
after
'AUTOCAL'
To
check
the
accuracy
after
'AUTOCAL'
the 'Speci-
fication Verification' section of the
Operating
Handbook
will
be useful.
It
provides tables for
quick reference of
accuracy
on
all
ranges
and functions
in
displayed
digits.