The functional unit consisting of the operating & display unit URB 55 / conductivity controller LRR 1-52 in conjunction with conductivity electrodes LRG 1.-.. and conductivity transmitter LRGT 1.-.. is used as conductivity controller and limiter, for instance in steam boilers, (pressurized) hot-water installations as well as condensate and feedwater tanks. The conductivity controller indicates when the preset MAX or MIN conductivity is reached, opens or closes a continuous blowdown valve and may also control an intermittent blowdown valve.

The conductivity controller can be used together with conductivity electrodes and transmitters in the following equipment combinations: Conductivity controller LRR 1-52 together with conductivity electrodes LRG 12-2, LRG 16-4, LRG 16-9, LRG 17-1 and LRG 19-1; Conductivity controller LRR 1-53 together with conductivity transmitters LRGT 16-1, LRGT 16-2 and LRGT 17-1.