LFE 2000 Series - Page 66

958-ll
REV.
B
7
.l
7
,1.1
iNPUT
TEST
THERMqCOUPLE
INPUT
SECTION
7
-
ADJUSTMENT
AND
TEST
ICE_BATH
REFERENCE
7.1.
l.
I
TEST
EQUTPMENT
DC
MILLIVOLT
CALIBRATOR
-
A
nlcrovolt
resolutlon
accurate
1000.
7
.t.1.2
INPUT
CALIBRATION
CHECK
Connect
a
calibrator
and
Section
7.1.1.
l.
stable
distortion
free
calibrat,or
with
a
rninimurn
of
10
to
t0.0IZ,
and
with
an
output
impedance
of
less
than
Verification
calj-bration
nust
be
performed
using
a
suitable
therrnocouple
simulator
whose
output
is
referenced
to
0"c
(32'F).
An
ice-bath
reference
may
be established
usint
speclal
copper
vs
therrnocouple
wj.re
assemblies
and
a
thermos
contarnjng
dlstilled
water
and
crushed
ice
as
rndlcated
in
the
sketch
below.
The
ice/water
solution
must
be
circulated
contrnuouslv.
COPPER
WIRE
THERMOCO
/TTHERMOCOUPLE
WrRE
lr
_
DC
CALIBRATOR
I
I
F
H
n_lT
I
I
I
I
J
I
I
L
SERIES
2OOO
CONTROLLER
I,
)
3.
4,
an
ice-bath
reference
r_o
the
controller
as
showrr
in
Using
a
standard
therrnocouple
table
millivolt
equivalent
for
a
partj-cular
using
the
callbrator.
such
as
NBS
Monograph
125,
apply
the
temperature
within
the
controller's
span
The
controller
di-splay
should
lndicate
the
selected
temperature
within
its
rated
tolerance
after
2
minutes.
Repeat
for
other
temperatures
within
the
controller
span.
-5
9-
t,FE
Instruments
Divrsion