SMAR LD303, Operation And Maintenance Instruction Manual, Page: 9 / 110

Section 1
1.1
INSTALLATION
General
NOTE
The installation carried out in hazardous areas should follow the recommendations of the
IEC60079-14 standard.
The overall accuracy of a flow, level, or pressure measurement depends on several variables.
Although the transmitter has an outstanding performance, proper installation is essential to
maximize its performance.
Among all factors, which may affect transmitter accuracy, environmental conditions are the most
difficult to control. There are, however, ways of reducing the effects of temperature, humidity and
vibration.
The
LD303
has a built-in temperature sensor to compensate for temperature variations. At the
factory, each transmitter is submitted to a temperature cycle process, and the characteristics under
different pressures and temperatures are recorded in the transmitter memory. At the field, this
feature minimizes the temperature variation effect.
Locating the transmitter in areas protected from extreme environmental changes can minimize
temperature fluctuation effects.
The transmitter should be installed in such a way as to avoid, as much as possible, direct exposure
to the sun or any source of irradiated heat. Installation close to lines and vessels with high
temperatures should also be avoided. Use longer sections of impulse piping between tap and
transmitter whenever the process fluid is at high temperatures. Use of sunshades or heat shields to
protect the transmitter from external heat sources should be considered.
Humidity is fatal for electronic circuits. In areas subjected to high relative humidity, the O-rings for
the electronic housing covers must be correctly placed and the covers must be completely closed by
tightening them by hand until the O-rings are compressed.
Do not use tools to close the covers. Removal of the electronics cover in the field should be reduced
to the minimum necessary, as each time it is removed; the circuits are exposed to the humidity. The
electronic circuit is protected by a humidity proof coating, but frequent exposure to humidity may
affect the protection provided. It is also important to keep the covers tightened in place. Every time
they are removed, the threads are exposed to corrosion, since painting cannot protect these parts.
Code-approved sealing methods should be employed on conduit entering the transmitter. The
unused outlet connection should be plugged accordingly.
Although the transmitter is virtually insensitive to vibration, installation close to pumps, turbines or
other vibrating equipment should be avoided. Proper winterization (freeze protection) should be
employed to prevent freezing within the measuring chamber, since this will result in an inoperative
transmitter and could even damage the cell.
NOTE
When installing or storing the level transmitter, the diaphragm must be protected to avoid
scratching-denting or perforation of its surface.
The transmitter has been designed to be both rugged and lightweight at the same time. This makes
its mounting easier; mounting positions are shown in Figure 1.1.