Industrial Controller MCU 200 Series

The MCU controller and gap sensor when used together provide an ultrasonic point level liquid switch. Typical applications include sludge blanket level detection in settlement tanks, interface detection for immiscible liquids and contamination detection, such as oil in water or water in oil. The MCU201 and MCU203 level control units provide simple and economical control electronics for wall-mounting near a tank or pipeline containing a single ultrasonic gap sensor. The sensors operate on the attenuation of an ultrasonic signal through the fluid.

Ultrasonic liquid point level switches (gap type sensors) are used in non-hazardous area industrial processes to detect high or low liquid levels or liquid interface. Mobrey ultrasonic point level switches are activated when there
is a liquid present between the sensor’s transmitter and receiver crystals. In this way, the absence of liquid results in a low level being indicated. The level switches are fitted with dual-coaxial cable for connection to a control unit. This cable can be extended with suitable coaxial extensions up to 164 ft. (50 m). Typical applications include interface detection duty for immiscible liquids and sludge blanket level.


  • Wall-mounting IP65 polycarbonate enclosure
  • DPDT relay output for wet-to-dry or dry-to-wet changeover indication, external control, or alarm condition indication.
  • Accepts a voltage-free contact input e.g. to actuate a pump control function via the output DPDT relay
  • Three LED indicators – Normal, Alarm, and Fault
  • Selectable time delay (0.5, 2, 8 or 30 seconds) for wet-to-dry or dry-to-wet changeover
  • Continuous cable check between controller and Mobrey 400SD Point Level Detector


  • A wall-mountable Mobrey MCU200 Series industrial control unit for monitoring the level switch state and provide the required switching function
  • A tank-mountable Mobrey 402SD or 433SD ultrasonic point level switch containing transmitter and receiver piezo-electric crystals


Mobrey MCU200 SeriesMCU201 MCU203 
Number of Level Switch Inputs1 1 
Power Supply (Selector Switch)110/120 Vac or 220/240 Vac selectable 24 Vdc grounded (earthed) negative 
Power Consumption6 VA 2.4 W 
Relay OutputDouble-Pole Changeover (DPDT) 
Energized when sensor is wet or dry (selectable by switch) 
Relay Rating5A at 230V 5A at 230V 
Box Dimensions7.9 x 4.7 x 3 in. (200 x 120 x 75 mm) 7.9 x 4.7 x 3 in. (200 x 120 x 75 mm) 
Box RatingIP65 Polycarbonate IP65 Polycarbonate 
Holes for glands3 off 0.63 in. (16 mm) diameter 3 off 0.63 in. (16 mm) diameter 
Fixing centres (WxH) for Wall Mount7.4 x 3.4 in. (188 x 88 mm) 7.4 x 3.4 in. (188 x 88 mm) 
Fixing Hole Diameter0.16 in. (4 mm) 0.16 in. (4 mm) 
Frequency SelectionBy switch on PC board By switch on PC board 
 Visible through the box lid  
LED IndicatorsGreen for normal. Red for alarm condition. Amber LED for fault condition 
 Selectable for wet/dry sensor, as appropriate for the application 
Gain PotentiometerFitted with scale and separate range switch to adjust for sensor type and site conditions 
 Selectable delay of 0.5, 2, 8 or 30 seconds  
Response TimeDelay selectable for wet-to-dry or dry-to-wet changeover  
 50 ms response in opposite direction  
Sensor Cable CheckSelectable to monitor coax screen to sensor for continuity  
Fault lights fault LED and sets relay to alarm state  
Auxiliary InputExternal closed circuit input to MCU200 latches the output relay to achieve pump control 

Download Data Sheet: Industrial Controller MCU 200 Series