SECTION
1-1
1
1
Introduction
OVERVIEW
This section contains general transmitter safety information, a brief description of
each model covered in this manual, and a summary of each of each section.
SAFETY MESSAGES
Procedures and instructions in this manual may require special precautions to
ensure the safety of the personnel performing the operations.
SAFETY NOTICE
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:
n
Sustained drift rate in true zero and span or operating point output or both
n
Sluggish response to increasing or decreasing pressure or both
n
Limited output rate or very nonlinear output or both
n
Change in output process noise
n
Noticeable drift in operating point output
n
Abrupt increase in drift rate of true zero or span or both
n
Unstable output
n
Output saturated high or low
4690.bk : 4690.s1 Page 1 Tuesday, May 26, 1998 5:28 PM
