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Freezer Liquid Nitrogen Level Detector/Alarm.

Model LD 215: Product Information

Model LD 215 Liquid Nitrogen Level Detection/Alarm System.


  • Audible & visual alarms.
  • SPDT alarm contact output.
  • 100-ohm cryogenic RTD probe.
  • 0.250-inch/6.35 mm optimum level change resolution.
  • Low-level or overflow mode operation.


Made in USA Emblem

Product Overview:

The Model LD 215 enables monitoring of liquid nitrogen levels in ultra cold freezer storage systems where maintaining safe cold storage temperatures is critical. Such applications include medical laboratories, biological research labs, and in vitro fertilization (IVF) clinics.

The Model LD 215 monitors liquid nitrogen levels in freezer vessels using a special 100-ohm cryogenic RTD probe located within the freezer unit. The system is able to sense a slight rise in temperature due to cryogenic liquid level drop caused by evaporation. When this happens, an alarm condition is triggered and action can be taken. The system can also be used to detect overflow liquid nitrogen (LN2) levels.

Level indication resolution is approximately 1/4-inch (due to frost accumulation potential on the probe and the ambient temperature within the container). However, once an ideal position is established, the probe will repeatably detect low or high LN2 levels.

An out-of-tolerance alarm condition is signaled by a flashing red LED and a pulsing beeper. If the probe is disconnected (open) the red LED and beeper will remain on steadily. Alarm conditions can also be muted for a user-selectable period of up to 60 minutes.

The unit is shipped with a plug-in power supply and battery back-up. Alarm relay single-pole double throw (SPDT) contacts are brought out to tool-less spring-loaded connectors.

Model LD 215 Documentation:

LD 215 - Pricing

LD 215 - Brochure

LD 215 - Manual

Warrany, Shipping and Return Info


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