LHe and LN2 level indicators

Janis Research offers liquid helium and liquid nitrogen level indicators from top industry suppliers. Model specifications are listed below. If you do not have a preferred model, Janis will supply the indicator most appropriate for your system.

Janis — a Lake Shore Company

Model LM-510 liquid cryogen monitor

The LM-510 liquid cryogen level monitor is a compact instrument featuring all commonly requested functions controlled via the front-panel keypad.

Features of the LM-510:

  • 240 × 400 TFT LCD display—the large viewing angle and high contrast multi-color display makes it easy to see liquid cryogen levels and status of alarms/refill cycle
  • Full numeric keypad with directional arrows—unit setup is easier than ever with the expanded keypad
  • Ethernet and USB computer connectivity standard
  • 4 to 20 mA and 0 to 10 V analog output standard
  • Options for IEEE-488.2 or RS-232
  • Universal power input—100 to 240 VAC, 50 to 60 Hz
  • Compact dimensions—7.25 in width × 2.50 in height × 7.00 in depth (184 mm × 64 mm × 178 mm)

The LM-510 also contains the most popular features of the LM-500:

  • Configurable as a single channel unit to monitor liquid helium or liquid nitrogen
  • Optional dual channel configuration can simultaneously monitor:
    • Two liquid helium level sensors
    • Two liquid nitrogen level sensors
    • Or one of each
  • Separate alarm (or refill setpoints) for each channel
  • Sample and hold operation, burnout protection, and de-ice cycle for liquid helium level sensors
  • level indication in centimeters, inches, or %
  • Optional rack mount panel
  • Optional line-voltage output controller used to automate liquid nitrogen refills
  • Free LabVIEW® drivers
LM-510 Setup Menu LM-510 Single Channel LN2 Screenshot LM-510 Liquid Cryogen Level Monitor LM-510 Rear Panel

Model 110A liquid helium level meter

The low-cost Model 110A liquid helium level meter reliably measures the helium level in a Dewar. A 3.5 in analog display provides 0 to 100% liquid helium level indication. A 0 to 10 V recorder output is provided on the rear panel of the instrument. The Model 110A can be used with any AMI liquid helium level sensor up to 60 in in active length.

Model 110A Specifications
Input power:90 to 132 VAC or 180 to 264 VAC, 50 to 60 Hz
Sensor current:75 mA
Linearity:±2% of full scale
Absolute calibration:±2% of full scale
Display:3.5 in analog meter
Recorder output:0 to 10 V standard (0 to 100 mV optional)
Dimensions:3.8 in H × 8.4 in W × 10.75 in D, standard (3.5 in H × 19 in W × 10.75 in D, rack mount)
Weight:4.0 lb standard; 4.7 lb rack mount
AMI_110A Liquid Helium Level Meter

Model 135 sample-and-hold level monitor

The Model 135 is an advanced liquid helium level monitor that incorporates AMI's patented sample-and-hold design with automatic helium level sensor vacuum burnout protection. The Model 135 is ideal for operation in systems where it is important to monitor the liquid helium level while also minimizing the helium losses.

Model 135 Specifications at 25 °C
Level Measurements
Resolution:0.1%, 0.1 cm, or 0.1 in
Accuracy:±0.5% of active sensor length
Sensor Current:75 mA nominal
Sensor Voltage:approximately 70 VDC for 80 in active sensor length
Operating Parameters
HI and LO alarms:0% to 100% adjustable
HI/LO alarm relay contact ratings:30 VAC or 60 VDC, 10 VA (up to 0.5 A max) [normally open, closed on alarm]
Sample-and-Hold Period:0.1 to 600.0 min (or h)
0 to 10 V analog output
Integral Non-linearity:±0.012%
Resolution:16 bits
Total Error:±1.1%
Voltage Drift (0 to 10 V):100 ppm/°C
4 to 20 mA analog output at 24 V
Vext Supply Range:13 to 32 VDC
Integral Non-linearity:±0.012%
Resolution:16 bits
Total Error:±0.25%
Current Drift (4 to 20 mA):75 ppm/°C
PSRR:10 µA/V
Power Requirements
Primary*:100 to 120 or 200 to 240 VAC ±10% 50 to 60 Hz, 50 VA
Dimensions (Standard):97 mm H × 213 mm W × 273 mm D (3.8 in H × 8.4 in W × 10.75 in D)
Weight (Standard):1.8 kg (4.0 lb)
Dimensions (Rack Mount):89 mm H × 483 mm W × 273 mm D (3.5 in H × 19 in W × 10.75 in D)
Weight (Rack Mount):2.3 kg (5.0 lb)
Ambient Temperature:Operating: 0 °C to 50 °C (32 °F to 122 °F)
Non-operating: -20 °C to 60 °C (-4 °F to 140 °F)
Relative Humidity:0% to 95%, non-condensing

*Maximum active sensor length is limited to 68 in for input line voltages below 105 VAC or 210 VAC.

Microprocessor-based electronics provide 0.1% readout accuracy. Nonvolatile, read-only memory maintains instrument calibration without battery backup. Watchdog timer circuitry and low line voltage (brownout) detector prevent microprocessor lock-up and provide fail-safe operation.

AMI_135 Liquid Helium Level Monitor