Rosemount 1151GP - Transmitter Disassembly

Reference Manual
00809-0100-4360, Rev BA
August 2008
Rosemount 1151
5-12
Transmitter Disassembly Read the following information carefully before you disassemble a transmitter.
General information concerning the process sensor body, electrical housing,
and a procedure for their separation follow. Figure 5-4 shows an exploded
view of the transmitter.
Electrical connections are located in a compartment identified as TERMINAL
SIDE on the nameplate. The signal and test terminals are accessible by
unscrewing the cover on the terminal side. The terminals to the housing must
not be removed, or the housing seal between compartments will be broken.
(Not applicable to R1 Option.)
The following performance limitations may inhibit efficient or safe operation. Critical
applications should have appropriate diagnostic and backup systems in place.
Pressure transmitters contain an internal fill fluid. It is used to transmit the process
pressure through the isolating diaphragms to the pressure sensing element. In rare
cases, oil leak paths in oil-filled pressure transmitters can be created. Possible causes
include: physical damage to the isolator diaphragms, process fluid freezing, isolator
corrosion due to an incompatible process fluid, etc.
A transmitter with an oil fill fluid leak can continue to perform normally for a period of
time. Sustained oil loss will eventually cause one or more of the operating parameters
to exceed published specifications while a small drift in operating point output
continues. Symptoms of advanced oil loss and other unrelated problems include:
• Sustained drift rate in true zero and span or operating point output or both
• Sluggish response to increasing or decreasing pressure or both
• Limited output rate or very nonlinear output or both
• Change in output process noise
• Noticeable drift in operating point output
• Abrupt increase in drift rate of true zero or span or both
• Unstable output
• Output saturated high or low
Explosion can cause death or serious injury. Do not remove the instrument cover in
explosive atmospheres when the circuit is alive.
Explosions can cause death or serious injury. Do not break the housing seal in
explosive environments. Breaking the housing seal invalidates the explosion-proof
housing rating.