LC11 Liquid Nitrogen Level Controller with Alarm Output

The LC11 Controller uses two LS10 Sensors to maintain the liquid level in a cryogenic reservoir. A third LS10 Sensor is used to detect a "level alarm" condition. A jumper on the LC11 circuit board determines if the third sensor is used for a high or low level alarm. The LC11 is powered from 120VAC (230VAC optional) and is supplied as a circuit board with screw terminals and mounting holes.

The controller uses an on-board solid-state relay to operate a cryogenic solenoid valve (sold separately). The LC11 will activate the relay when the low-level LS10 sensor is no longer submerged in LN2. Filling continues until the high-level LS10 sensor becomes submerged. As a safety feature, the controller will not initiate (or continue) a fill operation if any sensor is unplugged.

The LC11 circuit board is equipped with three jacks that accept the LS10 Sensors. Screw terminals are used to make all other connections to the LC11 circuit board. In addition to the power and relay terminals, the controller also has STATUS, ALARM and FILLING outputs as well as a TOGGLE input.

The STATUS output indicates that the sensors are installed and operating properly. If all three sensors are functioning, the STATUS output is connected to COMMON. Otherwise the STATUS output flashes between COMMON and open to indicate a fault condition. The FILLING output can be used by external equipment to monitor the LC11's filling status. This open-collector output is connected to COMMON only when the solid state relay is activated. The open-collector ALARM output is connected to COMMON when a level alarm is detected or if there is a sensor fault condition.

The TOGGLE input permits external control over the filling process. If the liquid level is between the two high and low sensors, then momentarily shorting the TOGGLE terminal to COMMON will cause the status of the controller to toggle from the filling state to the waiting state or vice versa. If the high and low sensors are both dry, shorting TOGGLE to COMMON will disable filling until TOGGLE is released from COMMON. Finally, If both sensors are wet (or if any sensor is unplugged), TOGGLE can be used to override the controller and force-fill the reservoir.

The LC11's features include:

Automatic 2-Point Level Control
High or Low Level Alarm Indication
Sensor Status Indication
Filling Indication
Controller Override
Compact Size
Low Cost
Easy Installation
1 Year Warranty
Made in the USA

Download the LC11 User Manual

           PDF LC11 User Manual (344 KB)

LC11 Specifications

Power: 120VAC @ 3Amps (230VAC optional)
Size: 3.13 in. (L) x 3.0 in. (W) x 1.5 in. (H)
Fill Relay: 120VAC @ 2.5Amps (230VAC optional)
Required Sensors: LS10, 3 each
Input Signal: TOGGLE
Output Signals: ALARM, STATUS and FILLING
Output Power Supply: 5VDC @ 90mA
Screw Terminals: Accepts 14 to 30 AWG
Mounting Holes: 2.5 in. square pattern, 0.15 in. I.D.
Specifications are subject to change without notice.
Inquiries regarding custom applications are welcome.

U.S. Pricing

LC11 Controller: $365
LS10 Sensors (2, 3 or 4 foot lengths): $99 each
SX10 Non-cryogenic sensor extensions (6 foot): $79
Prices are FOB San Francisco and are subject to change.
LC11 Photo

LC11 Application

Typical LC11 Application

LC11 Circuit Board

LC11 Circuit Board

LS10 Sensor

LS10 Sensor



      LC2 Controller
      LC10 Controller
      LC11 Controller
      LP7 Transmitter
      AL10 Alarm
      LS2 Sensor
      TA1 Transfer Line
      PM70 Meter

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