<s>
The	O
Weston	B-Algorithm
cell	I-Algorithm
or	O
Weston	B-Algorithm
standard	I-Algorithm
cell	I-Algorithm
is	O
a	O
wet-chemical	O
cell	O
that	O
produces	O
a	O
highly	O
stable	O
voltage	O
suitable	O
as	O
a	O
laboratory	O
standard	O
for	O
calibration	B-General_Concept
of	O
voltmeters	O
.	O
</s>
<s>
The	O
electrolyte	O
is	O
a	O
saturated	O
solution	O
of	O
cadmium	O
sulfate	O
,	O
and	O
the	O
depolarizer	B-Algorithm
is	O
a	O
paste	O
of	O
mercurous	O
sulfate	O
.	O
</s>
<s>
Electrical	O
connections	O
to	O
the	O
cadmium	O
amalgam	O
and	O
the	O
mercury	O
are	O
made	O
by	O
platinum	B-Operating_System
wires	O
fused	O
through	O
the	O
lower	O
ends	O
of	O
the	O
legs	O
.	O
</s>
<s>
The	O
original	O
design	O
was	O
a	O
saturated	O
cadmium	B-Algorithm
cell	I-Algorithm
producing	O
a	O
reference	O
and	O
had	O
the	O
advantage	O
of	O
having	O
a	O
lower	O
temperature	O
coefficient	O
than	O
the	O
previously	O
used	O
Clark	B-Algorithm
cell	I-Algorithm
.	O
</s>
<s>
However	O
,	O
an	O
unsaturated	O
cell	O
's	O
output	O
decreases	O
by	O
some	O
80	O
microvolts	O
per	O
year	O
,	O
which	O
is	O
compensated	O
by	O
periodic	O
calibration	B-General_Concept
against	O
a	O
saturated	O
cell	O
.	O
</s>
