Emerson 3-9000-771A User Manual

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Daniel 3818 LNG Liquid Ultrasonic Meter Installation Manual
Section 1: Introduction
3-9000-771 Rev A
May 2012
3818 LNG Liquid Ultrasonic Flow Meter design
 7
Computer simulations of various velocity profiles demonstrate that eight measurement paths 
provide an optimum solution for measuring asymmetric flow. The Daniel 3818 LNG Liquid 
Ultrasonic Flow Meter utilizes eight cross-bore, parallel-plane measurement paths to offer a high 
degree of accuracy, repeatability, and superior low-flow capabilities without the compromises 
associated with conventional technologies. The meter is comprised of two 3810 Transmitter 
Electronics, designated as co-located primary (master) and secondary (slave)  electronics. A syn-
chronization cable connects the primary and secondary Acquisition Modules at the J6 terminal 
block and the liquid ultrasonic flow meter firmware controls the transducers firing sequencing. 
The Daniel 3818 LNG Liquid Ultrasonic Flow Meter with the 30” diameter meter body utilizes 60 
degree port angles with LT-07 transducers.
These features make the Daniel 3818 LNG Liquid Ultrasonic Flow Meter the best choice for 
cryogenic custody transfer applications as shown in the following sections of this manual.
The Daniel 3818 LNG Liquid Ultrasonic Flow Meter’s U.L. safety listing is accomplished through 
the combination of a remote mounted, explosion-proof Transmitter Electronics Enclosure that 
houses the CPU Module, I.S. Barrier Module, Power Supply Board, and the Backplane Board. The 
flameproof Base Electronics Enclosure houses the Acquisition Module and the acquisition board 
cable connections. The intrinsically safe transducers and cable assemblies are designed for Class 
1, Division 1, Groups C and D areas without need of further protection when installed in 
accordance with the field wiring diagram (refer to Daniel drawing DMC - 004936,
 
 
) and the meter body (spool piece).