<5. Maintenance>
5-6
IM 02C01B04-01EN
5.9 Further Disassembly
IMPORTANT
Normal servicing of the transmitter does not
require the removal of any parts other than those
already mentioned. Further disassembly is not
recommended by YOKOGAWA. The following
procedures are described for emergency use only
and the user must assume responsibility for loss of
accuracy or damage to the transmitter.
31
25
30
26
29
27
28
F0521.ai
Dashpot nut
Dashpot
Dashpot
clamp
Dashpot flexure
Flexure mounting
bracket
Dashpot clamp
screws
Parts associated with
servicing of dashpot.
Flexure locking
screw
5.9.1 Dashpot Removal
1. Remove flexure locking screw
26
, and loosen
the two dashpot clamp screws
28
. Lift out
dashpot assembly. Disconnect flexure
25
by
unscrewing dashpot nut
31
.
Caution: In removing and replacing dashpot nut, keep dashpot
30
from turning by putting a thin, open-end wrench
across flat sections of dashpot just under flexure.
2. To replace assembly, position narrow slotted
hole of flexure on dashpot stud. Put washer
on stud and loosely screw on nut
31
. Slide
dashpot into clamp. Position flexure laterally
so that slotted hole in free end is approximately
centered on tapped hole under it. Tighten nut
31
.
3. Adjust height of dashpot until free end of flexure
just touches flexure mounting bracket
27
.
Tighten the two clamp screws
28
. Loosely insert
flexure locking screw
26
and its washer in place.
5.9.2 Dashpot Alignment
1. With air supply on, there must be some output
from transmitter.
2. Loosen flexure locking screw
26
just enough
to allow free vibration of adjacent parts. Put
a finger on dashpot nut
31
and gently move
dashpot assembly back and forth (total travel is
about 1 mm) in line of flexure. When assembly
is in middle of its travel, tighten flexure locking
screw
26
. Flexure
25
must be flat and horizontal.
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2
3
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12
13
14
16
15
17
18
19
11
20
21
5.9.3 To Remove Feedback Bellows and
Zero Spring (behind Zero Screw)
1. Carefully pry out feedback O-ring connection at
amplifier (Refer to section 5.4).
2. Using 7/16" open-end wrench, remove the two
1/4" cap screws
12
holding bracket
11
.
3. Unscrew completely zero adjustment screw
13
to release zero spring. Bracket
11
and feedback
bellows
15
can now be removed.
4. Remove nut
14
to disconnect feedback bellows
from bracket.
5. Remove zero spring by unscrewing it from
range bar
16
. Be careful not to change
alignment on the spring clamp.
6. Reverse this procedure to reassemble, making
sure that post on bracket is within zero spring
alignment clamp. Tighten zero adjustment
screw until about 6 mm of thread remains
exposed. When replacing feedback connection,
apply a thin film of Vaseline or similar lubricant
to O-ring.
7. Check calibration (Refer to section 5.1.2).
