Emerson 3812 Benutzerhandbuch

Seite von 138
12
Daniel 3812 Liquid Ultrasonic Flow meter design
Section 1: Introduction
Daniel 3812 Liquid Ultrasonic Flow Meter Installation Manual
May 2015
3-9000-765 Rev H
Figure 1-8  Optional local display and glass endcap 
The Daniel 3812 Liquid Ultrasonic Flow Meter is a two-path (four transducers) in-line meter 
designed to measure the difference in signal transit time with and against the flow across one or 
more measurement path(s). A signal transmitted in the flow direction travels faster than one 
transmitted against the flow direction. Each measurement path is defined by a transducer pair 
in which each transducer alternately acts as transmitter and receiver. The meter uses transit 
time measurements and transducer location information to calculate the mean velocity.
Computer simulations of various velocity profiles demonstrate that multiple measurement 
paths provide an optimum solution for measuring asymmetric flow. The Daniel 3812 Liquid 
Ultrasonic Flow Meter utilizes two cross-bore, parallel-plane measurement paths, offers a high 
degree of repeatability, bi-directional measurement and superior low-flow capabilities without 
the compromises associated with conventional technologies. 
The Daniel 3812 Liquid Ultrasonic Flow Meter’s U.L. safety listing is accomplished through the 
combination of an explosion-proof Transmitter Electronics Enclosure that houses the CPU 
Module, Power Supply board, I.S. Barrier board, Backplane board and optional LCD Display 
board.  
 
NOTE: 
The optional LCD Display requires firmware v1.04 and Uboot version, January 31, 2013.
The Base Electronics Enclosure is intrinsically safe and houses the Acquisition Module, the 
acquisition cable and wiring. 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