Magnesonics Level Equipment 

 

Jerguson Series JDT Displacer Level Transmitter

Changing process liquid level causes the displacer element, which is supported by a spring, to rise or fall. An armature, located in the pressure tube of the head, is directly linked to the displacer and moves vertically with the displacer element. In the enclosure and around the outside of the pressure tube is a Linear Variable Differential Transformer (LVDT) which provides an output proportional to the position of the armature within the pressure tube. Sophisticated surface mount electronics process the voltage signal from the LVDT into a 4-20mA output signal. The pressure tube is made of stainless steel and is welded to the enclosure fitting effectively containing the process pressure and temperature. This design ensures process conditions are contained and isolated in the pressure vessel. Dimensional Information

The displacer length is determined by the operating range (span) specified, the S.G., pressure. and temperature of the process. The diameter and weight are factory calculated to ensure the correct operation of the armature in the head. providing accurate 4-20mA output.

Each transmitter is fitted with a visible LED which flashes once every 3 seconds to show the instrument is operating and functioning correctly. The instrument span or zero may be adjusted on line by using the unique Mobrey "Caliplug" and a magnet screwdriver.  Larger Image of MLT100

 
FEATURES:
  • 2 wire 24 DC Loop Powered
  • 4-20 mA Output
  • Hart Digital Communications
  • Explosion Proof and I.S. Versions
  • Simple Local or Remote Calibration
  • Non-interactive Zero and Span
  • Level, Contents or interface measurement
  • Optional local indicator
 
DESCRIPTION:

The Mobrey Level Transmitter is one of the most advanced available, utilizing the time proven buoyancy principle and incorporating state of the art electronics for high reliability and stability.

The transmitter may be mounted directly into a vessel or externally in a chamber to allow isolation for maintenance or onsite calibration checks. The 4-20rnA output from the head is proportional to the level or contents in the vessel, or may be used to measure an interface. The Mobrey transmitter supports the HART protocol as standard, which is superimposed on the 4-20mA signal. The user may operate the transmitter without digital communications or take advantage of the many features of'11ART such as remote calibration. reranging, on-line diagnostics and multidrop installations.

 
APPROVALS:
  • CENELEC EExd IIc T6 Certificate No. Ex 97D1291X
  • CENELEC EEx ia IIc T5 (-40 °C to +40 °C) Certificate No. Ex97D2379X
  • CENELEC EEX is IIc T4 (-40 °C to +80°C) Certificate No. Ex97D2379X
  • UL Cl. 1. Div.II Grps. B, C. & D
 
APPLICATION:

The Mobrey MLT will operate in most level measurement ap­plications including:

  • Knock-out pots
  • Condensate drums
  • Separators
  • Flash vessels
  • Storage vessels
  • Receiver tanks
Most liquids can be measured, if wetted materials are chosen to suit, at operating process temperatures between -76 °F to -608°F and pressures between full vacuum and 2200 PSIG (up to 3705 as a special). Typical liquid S.G. range is from 0.25 to 1.5, and interface applications with an S.G. difference of 0.1 are also practical. The range of the instrument is dependent only upon the length of the element specified, though lengths over 10 feet are considered the longest avail­able due to shipping considerations.
 
FIELD ADJUSTMENTS:
Calibration

The transmitter is configured by the factory to operate in the process conditions advised at the time of order, and the displacer element dimensions are chosen to suit the maximum required span. However, provisions are made to check the calibration once on site and fine tune the calibration with the instrument in an empty vessel at 20°C, or with the instrument at operating conditions.

 
Local calibration
Several adjustments may be made in the field using the unique "Mobrey Magnetic Scroller" (MMS) and the "Caliplug". The MMS is a calibration tool with a magnetic tip, and is used on the MLT100 and other Mobrev instruments to access and adjust certain operating parameters. The level transmitter is fitted with a " C: aliplug" calibration plug, which contains dock­ing ports for the MMS along with the heartbeat LED. The adjustments which may be made are as follows:
 
Setting the 4 mA and 20 mA points

May be accomplished locally at the transmitter by using the MMS to "zero" the device with the level at the required 4 mA point, then to "Span" the device with the level at the 20 mA point. The Zero and Span settings are non-interactive.

An additional feature is the ability to span the instrument without the vessel being filled to the 20 mA point. In this case, the vessel is filled to a known level and the output in­creased to give the corresponding mA level. The 20 mA point is then electronically calculated by the instrument provided the output is linear.

 
Remote calibration
Remote calibration is not necessary for standard 4-20 mA operation. Alternatively, the ranging may be accomplished by using a "SMART Communicator" to establish digital communications and set the 4 and 20 mA points electronically, without the need for changing the liquid level using HART protocol.
 
Local indication (optional)
A mufti-function LCD indicator housed in a cast aluminum explosion proof enclosure and finished in two part epoxy white paint. The 2 line display can be programmed to show output in percentage, engineering units and other operating parameters using the SMART communicator.
 
CONSTRUCTION:
Transmitter head
The transmitter head is cast iron with a paint finish of two part Epoxy white paint suitable for offshore or coastal use. 'Vetted parts are made from stainless steel which include the displacer element, trite and pressure tube. The spring is high alloy Nimonic suitable for corrosive liquids and high temperature.
 
Chamber

Where a chamber is specified, only certified materials to ANSI and ASTM are used. Welding is qualified to ASME IX and designed in accordance with ANSI B31.3.

All pressure retaining parts are hydrostatically pressure tested to a minimum of 1.50 times working pressures. Other NDT including radiography & dye penetrate testing is available when specified at time of order. Inspection by customers or their appointed agents is welcome provided this is requested at time of order.

 
SPECIFICATIONS:
  • Output: 4-20mA SMART/HART digital 10-120 in. (300-3000mm)
  • Range 10-120 in. (300-3000mm)
  • Max. operating pressure 2200 PSIG (153 bar) higher as special
  • Min. operating pressure Full vacuum
  • S.G. range standard 0.25 to 1.5 interface 0.1 difference
  • Max. operating temp. 608°F (320 ° C) (non-condensing)
  • Min. operating temp. -76 ° F (-60 ° C)
  • Ambient temp. -40 to -1 76°F
  • Accuracy -1 0 1 10 output span
  • Repeatability _-0.2°'0 of output span
  • Linearity 0.2°% of output span
  • Resolution 0.1 °o of output span
  • Hysteresis 0.3°.~ of output span
 
SMART/HART COMMUNICATOR OPTIONS:
Mobrey Hand Held Communicator

The HHC is fitted with a datapack which allows full access to all of the MLT100 parameters. May also be used with the Mobrey MSP100 ultra­sonic level transmitter and the Mobrey 4301 pressure transmitter. Ordering information: N4013REY-CKI

 
Mobrey Universal Hand Held Communicator
The Universal HHC can be programmed with the Device Description (DD) of any registered HART device to allow full access of all the instrument parameters. Mobrey offers a programming service which includes all HART devices registered with the HART Communication Foundation. regardless of manufacturer.
 
Mobrey H-View

A Windows based PC programming tool which allows full communication with Mobrey HART products. H-View provides access to all of the instrument parameters allowing programming and interrogation. Also supported is Dynamic Data Exchange (DDE) which allows export and import of any parameter or measured variable into a Windows package such as Microsoft Excel where dynamic mimics can be displayed. General note

All HART communicator devices from Mobrey allow access and programming of the universal commands and some common practice commands of any HART instrument, regardless of manufacturer.

 
 
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