While a vessel or reactor is being charged you can compare our switch point indications to any continuous unit's ouput. Our indicating points can't change once installed making them very reliable as backups to other forms of level measurement. (Example) When charging a critical reactor the operator or in many cases the control system compares our switch point indications to the output from the continuous level instrument. If they agree, then charge continues. If not, the reaction is aborted and a possibly serious accident is prevented.