Model
5528A
Di
stance
Mea
surements
6·28
b.
Multiply
the
number
you just entered (1.5 x
10
-6)
by the length
of
travel
(5
08
mm, or 20
inches) ar,d er
,ter
the
produ
ct in column " B" (0,
00080
nun
,
or
0.00031
ir
K h
).
5.
Identif
y th e accuracy
of
yo
ur
material temperature co
mp
en
sa
tion.
a.
Ide
nt
ify
the type
of
material you are
mea
s
ur
ing.
b.
Determine this material
's
coefficient of thermal e
Kpan
sion.
So
me typi
ca
l
val
ues
ar
e pre·
se
nted
below
. For
our
example,
we'll
u
se
"s
teel
".
steel
'"
11.7
ppm
per
degree
Ce
l
si
us
aluminum
"
23.6
ppm
per
desree
Ce
l
si
us
copper
=
16
.5
ppm
per
degree
Ce
l
si
us
c.
I
dentify
the accura
cy
of
your temperature
se
nsor. The
1075
7 Material Sensor
hasa
sped·
lied
accuracy
of
±O.
10
oC,
as
shown on
The
" Error Budget Worksheet" , (
These
values are
also given in the
la
se
r Measurement System's Service Manual
).
Mul
tiply this accuracy by
the
expansion
co
td f
icie
nt
and e
nter
the produCi in co
lumn
"
A"
11
.2
ppm
).
NOTE
To
attain the specified a
CCl
rra
cy of ±0.
10
o
C,
the
output
characteris
ti
cs
of
the
107
57
Material Sensor must
be
mat
ched to particular
55
0UA
Mea
surement Displa
y.
Plea
se refcr to the calibration matching
prace·
dure
in Section 4·
45
in
the
la
se
r Measurement
Syst
em
's
Service
Manual.
d.
Multipl
y the accuracy value you
Just
calculated
(1.2
ppm
) by the length
of
tra
ve
l (5
08
mm,
or
20 inches) and enter in
column
" B" (
0.00061
mm, or
0.000024
inch
).
6.
Since you should alwa
ys
be starting
your
mea
su
rements when the Optics are close together,
assume tha t the
error
due
to deadpath will always be n
eg
ligible.
7.
Multipl
y 0.1
ppm
~
the
accuracy
lim
i
ta
t
ion
of
the laser Measurement
Sys
tem it
se
lf
) by the
le
ngth
of
tra
ve
l
~
S08
mm, or
20
inches) and enter the
product
in column " 8"
~
O
,OOOO5
mm
,or
0.000002
inch
).
8.
Identif
y the
magnitude
of
the
cos
ine
error
in your
se
tup -
a.
Identif
y
how
much
mo
lion
there is between the
two
return
dot
s if the Optics arc moved
over
the
entire
m
eas
urement axis. (
Th
e
la
se
r Head's exit port s
hould
ha
ve
the small
o
pening
for thi
s,
and the
return
port
s
hould
ha
ve
the target in place
.)
The smallest
mo
ve
ment you are IIke
(y
to detect will be about 0
.25
mm (0.
010
inch).
This
value will be
"S"
in the formula below. For o
ur
example, we'll let "5" = " 0.
25
nun" (
0.010
inch).
b. Enler the length
of
Optic
tra
ve
l as
"D"
in the formula be
low
.
c. The
cos
ine
error
in yo
ur
se
tup
is -
E -
~
in
parts-pcr·
milli
on,
or
E X D, in absolute terms
60
,
where -
"S"
is the
movement
between return dot
s,
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