Automatic monitoring of ion exchange bed exhaustion - by measuring resistance of bed and of standard cell

摘要

In the establishment of the state of an ion exchanger bed by measuring the electrical resistance of the ion exchange bed by means of electrodes arranged therein and the resistance of a standard cell provided with electrodes and using the measured values to form a signal proportional to their quotient, which is used for monitoring the state of the bed and/or starting-up a regenerating process, setting off an alarm etc., (i) a potential or a digital magnitude is derived by electronic means directly or inversely proportional to the sum of a constant and the quotient and (ii) a standard cell is used with ion exchange material in the regenerated state and with treated water. Better results are obtd. when the standard cell resistance is measured for the regenerated ion exchange agent and treated water and that of the exchange bed is measured as close as possible to the posn. where the eluate leaves the exchange column, compared to the known technique in which the standard cell contains spert exchanger and untreated water.