Liquid Nitrogen Level Measurement
The TEC 3000 uses a differential pressure system to determine
the LN2 level to an accuracy of ± 0.5 in. (15 mm) and a
resolution of 0.1 in. (5.0 mm). Unlike alternative level
sensing systems, differential pressure allows the exact level
to be measured and displayed. Using the simple single point
calibration in a range of 3.0 in. to 48.0 in. (75 mm to 1220 mm),
the patented, self-maintaining, closed-loop system displays in
inches, millimeters, or a percentage full.
Automatic Liquid Nitrogen Level Control
The fully automated LN2 level control system is based on userdefined
parameters that can be electronically adjusted over the
entire level range. The parameters include Low Level Alarm, Low
Level Fill Point, High Level Fill Point and High Level Alarm. The
redundant Dual Solenoid Valves for overfill protection run on 24
VDC, 1.0 amp (max).
This exclusive feature provides an estimation of liquid usage
to track LN2 consumption and can provide an early failure
warning to allow sufficient time to implement corrective action
and save irreplaceable samples.
A total of 17 audio/visual alarms are used to alert the user to
any potential or developing problems. The alarms include:
High Temperatures, Low Temperatures, High Level, Low Level,
Liquid Usage, Maximum Fill Time, Gas Bypass, Temperature
Calibrations, Low Battery, Power Failure, Lid Open and
Remote Alarm Monitoring
The TEC 3000 Alarm monitoring includes a Global Remote
Alarm Relay, as well as four discrete contacts for High Level,
Low Level, Temp A High and Low Battery.
Two independent temperature measurement channels are
employed to accurately measure the temperature across the
entire storage space. The two platinum RTD sensors have an
accuracy of ± 1.0°C and a resolution of 0.1°C. The temperature
can be displayed in °C, °F or K. The single or two point
calibration also has altitude compensation for the highest
Hot Gas Bypass
This unique feature is able to vent warm nitrogen gas from
the supply line before initiating a fill. This prevents warm gas
from entering the freezer space, which helps maintain a stable
temperature gradient and increases the efficiency by reducing
excess LN2 evaporation.
Event Log / Data Storage
The TEC 3000 is able to store vital, unalterable, time-stamped
data in nonvolatile memory. This is a great tool for assessing
freezer performance and troubleshooting any problems. The
memory can store 30,000 events, an estimated 10 years of storage
capacity. The data includes time-stamped temperatures, LN2
level, liquid usage, and any alarms or events.
The multilevel security system comprised of up to ten userspecific
programmable passwords and four security levels can
be customized to grant or restrict personnel access to certain
menus and settings.
Two independent ports can be used to communicate with other
TEC 3000 controllers, a remote PC, serial printer, or other RS-
485 networks and devices. Options include ASCII, MODBUS,
Printer and One Fill All Fill (OFAF).