71-6417
45
Maintenance
Unabl
e t
o c
ali
brat
e
a sensor
(ex
cept O
2
sensor)
•
Y
ou
cann
ot set the
sensor
’s
“fresh
air”
rea
ding
to
z
ero.
•
Sensor sho
w
s “xxx”.
•
T
he gas cylinder
is
emp
ty
or o
ut-dated.
•
T
he sensor
is
def
ective.
1.
V
erify that the
gas
cylinder
contains an adequate and
fresh
sup
ply of
the calibrating gas.
2.
Replace the
sensor
as desc
ri
bed
la
te
r i
n t
his c
hap
ter
.
3.
If the
di
fficulties continue, co
nt
ac
t The
rmo
Fisher
Sci
ent
ifi
c,
for further
instructio
n.
Unabl
e t
o c
ali
brat
e
a sensor
(O
2
sensor only)
•
Y
ou
cann
ot fresh air
the
O
2
read
ing
to
20.9
.
•
T
he O
2
sensor
is defective.
1.
Replace
the
O
2
sen
sor
as
described
la
te
r i
n t
his
c
hapt
er
.
2.
If the
di
fficulties continue, co
nt
ac
t The
rmo
Fisher
Sci
ent
ifi
c,
for further
instructio
n.
T
a
ble 6-
1
T
rou
ble
s
ho
oting
(
C
o
ntinu
ed)
Co
nd
itio
n
S
ym
pto
m
(s)
P
ro
b
a
ble Cau
se(s
)
Re
co
mmen
d
e
d
Action
