h barry and ernest a dahl for battery monitoring system issued aug 12 1980 information from communications circuit 23 may then be fed on a two wire communication line to an external readout at the top of housing 10 or at a remote location such as an indicator panel 26 for example as shown in fig1 readout panel 26 as shown is comprised of a plurality of standard liquid crystal bar graphs 27 for example to indicate the liquid level within respective tanks with adjustment controls 28 and alarm lights or indicators 29 indicators 29 are usually set to provide an alarm when a critical level is reached within a storage tank and adjustment controls 28 can be used to set the critical level communications circuit 23 can be included in the indicator panel 26 for convenience if desired standard d c type readout meters and alarms may also be used at display panel 26 however this would require more multiple wire conductors a modification of the device of fig1 and 2 is illustrated in fig3 and 4 in this embodiment a substantially rectangular or square cross sectional tube shaped housing 30 is used one surface of the housing tube has continuous grooves formed along the.