The Model 7170 LN2 Level Gauge provides a digital display of LN2 level in a Dewar or container along with adjustable low and high level setpoints which initiate audible and visible alarm signals as well as a relay output for remote monitoring. The display shows liquid level from 0-100% of the active sensor length. It can be programmed to read out in inches or centimeters. Sensors are designed, sized, and configured for Mirion dipstick and integral cryostats. Consult the factory for applications involving non-Canberra™ branded cryostats.
In addition it has adjustable low and high level control setpoints and a relay which provides line voltage to a controlled ac output for operation of a solenoid valve. The control and alarm setpoints are readily adjustable by means of front panel controls. Setpoints are stored in non-volatile memory. This ac outlet is powered from the time the low setpoint is reached until either 1.) the high setpoint is reached or 2.) the user-programmed time-out is reached.
The models 7170-110 and 7170-230 include a cryogenic solenoid valve, for 100-120 V or 220-240 V operation respectively, as well as fill and vent hoses. LN2 supply containers are available for a complete automatic LN2 Fill System.
The 7170 Controller requires a source of LN2 at a pressure of 34 to 172 kPa gauge (5 to 25 psig). Mirion D-180 LN2 cylinder or their equivalents are highly recommended. A self-pressurizing withdrawal device (NTD-30/50) with a 30 or 50 liter Dewar can be used but it is not highly recommended because of marginal capacity and pressure for most applications. The liquid quality must be good at the point of consumption. This means there must be no ice in the liquid and that the supply line must not have excess heat losses.
- Solenoid valve with captive 3 m (10 ft) cord (110 V or 230 V)
- Hoses for fill and vent