4 | Baker Hughes
© 2019 Baker Hughes Company. All rights reserved.
WARNING
BEFORE installing, using or carrying out any maintenance tasks associated with this instrument, READ
THE INSTRUCTIONS CAREFULLY.
The 12400 Series complies with the essential safety requirements of the European Directive ATEX 2014/34/EU.
It is certified to be used in Gas or Dust explosive atmospheres, groups IIA, IIB, IIC and IIIC:
•
Category II 1GD
– zones 0, 1, 2, 20, 21 and 22 for the protection mode "ia"
•
Category II 2GD
– zones 1, 2, 21 and 22 for the protection mode "db" and “tb”
They also comply with the essential safety requirements of the European Directive EMC 2014/30/EU as
amended, for use within an industrial environment.
Products certified as
explosion proof equipment MUST BE
:
a)
Installed, put into service, used and maintained in compliance with European and/or national and local
regulations and in accordance with the recommendations contained in the relevant standards concerning
potentially explosive atmospheres.
b)
Used only in situations those comply with the certification conditions shown in this document and after
verification of their compatibility with the zone of intended use and the permitted maximum ambient
temperature.
c)
Installed, put into service and maintained by qualified and competent professionals who have undergone
suitable training for instrumentation used in areas with potentially explosive atmosphere. Such trainings are
not supported by Baker Hughes.
It is the end user's responsibility to:
•
Verify material compatibility with the application
•
Ensure proper use of fall protection when working at heights, per Safe Site Work Practices
•
Ensure use of proper Personal Protective Equipment
•
Take the appropriate actions to ensure that site personnel who are performing installation,
commissioning and maintenance have been trained in proper site procedures for working with and
around equipment, per Safe Site Work Practices
Baker Hughes reserves the right to discontinue manufacture of any product or change product
materials, design, or specifications without notice.
Under certain operating conditions, the use of damaged instruments could cause a degradation of the
performances of the system which may lead to personal injury or death.
Use only genuine replacement parts, which are provided by the manufacturer to guarantee that the products
comply with the essential safety requirements of the European Directives mentioned above.
1. LEVEL TRANSMITTER/CONTROLLER TYPE 12400 OPERATION
To be operational, the digital level and controller type 12400 must be mounted on a torque tube
and on a displacer chamber equipped with the displacer.
Any change in the level of liquid or the interface between two liquids will change the apparent
weight of the displacer and cause a change of the angle of rotation in the torque tube.
This angle is measured by a sensor and converted by an electronic module:
➢
Either to a standardized 4-20mA current, proportional with the change in level, when
configured as a
level transmitter
,
➢
Or, to a 4-20mA current, generated by a PID algorithm derived from the error between the
actual level of liquid and the local set point, when configured as a
level controller
.