Accessories and Ancillary Equipment

LHe & LN2 Level Indicators

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• 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 x 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
  • 4-20mA and 0-10V Analog Output Standard
  • Options for IEEE-488.2 or RS-232
  • Universal Power Input
    100-240Vac, 50-60Hz
  • Compact Dimensions
    7.25” width X 2.50” height X 7.00” depth (184mm X 64mm X 178mm)

  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 automatic liquid nitrogen refills
  • Free LabVIEW® drivers

• 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 inch analog display provides 0-100% liquid helium level indication. A 0-10 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 inches in active length.

  Model 110A Specifications
  Input power:	90-132 VAC or 180-264 VAC, 50-60 Hz
  Sensor current:	75 mA
  Linearity:	± 2% of full scale
  Absolute calibration:	± 2% of full scale
  Display:	3.5 in. analog meter
  Recorder output:	0-10 V standard (0-100 mV optional)
  Dimensions:	3.8" H x 8.4" W x 10.75" D, Standard 3.5" H x 19" W x 10.75" D, Rack Mount
  Weight:	4.0 lbs. Standard; 4.7 lbs. Rack Mount

• Model 135 Sample-and-Hold Level Monitor

  

  The Model 135 is an advanced liquid helium level monitor which 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
  Linearity:	± 0.1%
  Sensor Current:	75 mA nominal
  Sensor Voltage:	approx. 70 VDC for 80" 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 minutes (or hours)
  0-10 Volt Analog Output
  Integral Non-linearity:	±0.012%
  Resolution:	16 bits
  Total Error:	±1.1%
  Voltage Drift (0-10 V):	100 ppm / °C
  4-20 mA Analog Output @ 24 V
  Vext Supply Range:	13-32 VDC
  Integral Non-linearity:	±0.012%
  Resolution:	16 bits
  Total Error:	±0.25%
  Current Drift (4-20 mA):	75 ppm / °C
  PSRR:	10 µA / V
  Power Requirements
  Primary*:	100-120 or 200-240 VAC ±10% 50-60 Hz, 50 VA
  Physical
  Dimensions (Standard):	97 mm H x 213 mm W x 273 mm D (3.8" H x 8.4" W x 10.75" D)
  Weight (Standard):	1.8 kg (4.0 lbs)
  Dimensions (Rack Mount):	89 mm H x 483 mm W x 273 mm D (3.5" H x 19" W x 10.75" D)
  Weight (Rack Mount):	2.3 kg (5.0 lbs)
  Environmental
  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 inches 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.