HART HK51, Руководство по эксплуатации

Страница: 12 / 22

13
4.3 Mounting position
The correct mounting position of the transmitter on the process pipeline is
related to the medium being tested. Note the following conditions in order to
achieve the best installation effect:
◆ Prevent the transmitter from contacting with corrosive or overheated media
under test.
◆ Prevent dross from depositing in the pressure pipe.
◆ The pressure pipe shall be as short as possible.
◆ The liquid column indenter in the pressure pipe on both sides shall be
balanced.
◆ The pressure pipe shall be installed in a place with small temperature gradient
and temperature fluctuation.
◆ Prevent crystallization or low temperature icing in the pressure pipe.
4.4 Installation in hazardous locations
Smart explosion-proof transmitters shall be used in hazardous locations, and
smart explosion-proof transmitters are extensions of smart transmitters. The
working principle and basic structure are the same as the smart transmitter.
Smart explosion-proof transmitters are available in intrinsically safe and
explosion-proof versions. Explosion-proof and intrinsically safe instruments
comply with provisions of GB3836.1-2000 General Requirements for Explosion-
proof Electrical Equipment in Explosive Atmosphere.
The internal cavity of smart explosion-proof transmitter type can withstand an
explosion, and the internal explosion does not cause explosion of the externally
specified explosive mixture. Mark d conforms to GB3836.2-2000 Explosion-
proof Electrical Equipment Explosion-proof Electrical Equipment. "d" in Explosive
Atmosphere, the explosion-proof grade is ExdIICT6.
Smart - Transmitter intrinsically safe type: refers to the circuit system, the point
spark and thermal effects generated under normal working or specified fault
conditions can not ignite the specified explosive mixture, the mark ia conforms
to GB3836.4-2000 Electrical Equipment Intrinsically Safe Type “i” in Explosive
Atmosphere, the explosion-proof grade is Exia IICT6. The transmitter is used in
conjunction with an associated equipment safety barrier installed in the control
chamber to form an intrinsically safe explosion-proof system.
Monocrystalline Silicon High Stability Transmitter