Solartron 1287 - Page 16

Wi iupiu
4
S1
1287
IMPROVEMENTS
OVER 1286
The
SI1 286A ECI has
been established
for a number of
years as one of
the most
advanced
instruments
of its
type, and has
an
impressive
specification.
The
SI1287A
has an
enhanced specification
that enables even
more sensitive
measurements
to be made,
and opens up new
areas of application.
A
summary of
the improvements
is given below:
•
Extra current
range, giving
increased current
sensitivity: IpA
compared
to
lOpA
on 1286;
•
Floating
Working Electrode;
•
Reduced
measurement
noise;
•
Improved
DC sweep rate:
6mV/min up
to 6000V/min with
a resolution
of
150pV/min,
compared
to
1286’ s
6mV/min resolution;
•
Increased
maximum
DC polarization:
±1 4.5V, compared
to ±12.8V for
1
286;
•
Sweep
freeze capability;
•
Conformance
to
EMC standards.
Some
of
the
benefits
of these improved
specifications are
listed below.
The 1287
has an additional
current
measurement resistor which
adds
a
200nA
range with a
resolution
of IpA. Together with
the lpV voltage
sensitivity, and
the improved
measurement
noise,
the
1287
can measure
effects which
were
previously hidden
to the
researcher. This improvement
also
adds another decade
of impedance
range, allowing
measurements in excess
of 1G£2 to
be made
accurately.
The extra current
range and
lower measurement
noise also means
that frequency
sweep
measurements
can be made
more quickly, since the integration
time
on the
FRA
can be reduced.
A further
benefit
of this extra
sensitivity and lower
noise is that Electrochemical
Noise measurements
-
which require the
accurate simultaneous
measurement
of
very low
voltages
and currents
-
can
now
be made
to
yield
useful results.
The
ability to float
the working electrode
is of great benefit
in many industrial
applications where
the working
electrode has
to be grounded
-
for
tests on oil
pipelines, for
example. Even
in the laboratory,
equipment
may need
to be
grounded
for safety
reasons, and this
can now be handled
by 1 287.
The increased
maximum
polarization voltage
enables
experiments
to be
conducted
on 12volt
accumulators, which
typically have
a rest potential
of >13V.
The 1287
can be programmed
to freeze the
polarization after
a DC sweep,
rather
than
return it to zero.
This allows
any number of
sweeps to be performed
in
sequence without
the need
to turn the polarization
off, to minimize
disturbances
to the
cell.
1.6
CSB/SI1287 User
Guide/Issue AA