Jerguson TruLevel -- Self Powered Remote Reading Liquid Level Indicator

A). To 750 WSP, Trulevel is installed with natural compensation datum column and two isolating valves.  Boiler drums, heaters, and similar equipment falls into this category. See Example

B). Over 750 WSP, Trulevel is installed with the temperature compensated datum column and 3 valve equalizing manifold.  Most boiler, heater, marine and other steam/condensate applications can be handled with Trulevel. See Example

C). For boilers where all drum safety valves are set over 900 WSP the ASME Boiler Code allows the use of one water gage and two remote level indicators with Temperature compensated datum chambers and 3 valve manifolds.   Repeaters can provide additional remote readings. See Example

TRULEVEL System to 750 wsp

Deduct for no temperature compensated datum - 

Deduct for no Manifold - 

The Transmitter consists of a linear variable differential transformer (LVDT) and the supporting solid state electronics.  The moveable core of the LVDT is attached to the pointer in such a way that a change in the Trulevel's reading causes a change in the transformers magnetic coupling.  This is transduced by electronics into a standard 4-20 mA DC analog signal.  This standard process signal may be monitored by the Receiver or, with the installation of a converter, by a computer.

The Receiver is a switchboard class instrument that duplicates the readout of the Trulevel.  Its standard size allows for easy integration into instrument panels.  Since it is a passive receiver, one or more units may be used to monitor the transmitter's output.

A Solid State Alarm Unit is available to provide switch points for control or indicated functions.  The sensing unit is a photoelectric device consisting of a photoconductive cell excited by a long life subminiature lamp.   A shadow device attached to the Trulevel pointer passes between the lamp and photocell at an alarm point.   The resulting change in the signal of the photocell, when electronically amplified, excites a singlepole, double -throw relay.   This relay provides the contacts which may be wired normally open or normally closed.

Standard alarm units provide two, three, or four adjustable alarm points rated at signal level loads for electrical alarms or annunciator panels.  A separate time delay rated at 10 amps is available to operate pumps or fuel cutouts.

Audible and visual alarms are available to alert personnel when high or low alarm points are activated. Larger Image of Alarm Board