
88-1
88.1 Introduction
Almost every modern instrumentation system includes some form of digitizer, or analog-to-digital
converter (ADC). An ADC converts real-world signals (usually voltages) into digital numbers so that a
co
mputer
or di
gital
pr
ocessor
ca
n
(1
)
ac
quire
si
gnals
aut
omatically,
(2
)
st
ore
an
d
re
trieve
in
formation
ab
out
th
e
si
gnals,
(3
)
pr
ocess
an
d
an
alyze
th
e
in
formation,
an
d
(4
)
di
splay
me
asurement
re
sults
. A di
gi-
tizing
sy
stem
ca
n
do th
ese
jo
bs
wi
th
gr
eater
sp
eed,
re
liability,
re
peatability,
ac
curacy,
an
d
re
solution
th
an
a pu
rely
an
alog
sy
stem
no
rmally
ca
n
.
Th
e
tw
o
ma
in
fu
nctions
of an AD
C
ar
e
sa
mpling and quantization
. Th
ese
tw