WIGGENS 2755-25 Automated Liquid Nitrogen Level Control System
| Brand | WIGGENS |
|---|---|
| Origin | Germany |
| Model | 2755-25 |
| Configuration | Includes SL29GL-A glass cold trap, Dewar vessel, lid, exhaust tubing, and 25 L LN₂ storage tank |
| Compliance | Designed for cryogenic vacuum applications requiring stable condensation surface temperature and reproducible low-temperature operation |
Overview
The WIGGENS 2755-25 Automated Liquid Nitrogen Level Control System is an engineered solution for maintaining precise, continuous liquid nitrogen (LN₂) level within cryogenic cold traps used in high-vacuum and freeze-drying applications. It operates on a dual-sensor feedback principle: two calibrated capacitive or resistive level sensors—positioned at predefined high and low thresholds—monitor LN₂ volume in real time. When the level drops below the lower sensor, the system triggers automated refill via a solenoid-controlled supply line connected to the integrated 25 L insulated LN₂ reservoir. Upon reaching the upper sensor threshold, refilling ceases, ensuring stable thermal mass and consistent cold trap surface temperature (typically –196 °C). This closed-loop control architecture eliminates manual intervention, minimizes nitrogen waste, and sustains optimal condensation efficiency across extended operational cycles—critical for applications demanding uninterrupted vacuum integrity and reproducible ice-trapping performance.
Key Features
- Automated dual-threshold level control with programmable hysteresis to prevent rapid cycling of the solenoid valve
- Integrated 25 L vacuum-insulated LN₂ storage tank with pressure-relief venting and liquid-level sight gauge
- Compatible with WIGGENS SL29GL-A borosilicate glass cold trap (300 mm height × 90 mm diameter), optimized for high surface-area condensation
- Modular Dewar assembly with thermally isolated lid and standardized exhaust tubing (OD 12 mm, compatible with ISO-KF 25/40 vacuum fittings)
- Fail-safe design: includes overfill prevention, low-pressure alarm output (dry contact), and manual override port
- Electronically sealed enclosure rated IP54 for laboratory environments; operating ambient temperature range: 5–35 °C
Sample Compatibility & Compliance
The 2755-25 system is designed exclusively for use with cryogenically cooled vacuum cold traps in rotary evaporation, lyophilization, and high-vacuum distillation setups. It supports both glass (SL29GL-A) and stainless steel (S54V-K16-Z, sold separately) trap configurations. No direct sample contact occurs—the system interfaces solely with the LN₂ coolant loop. All wetted components comply with DIN 12878 (cryogenic vessel standards) and are constructed from oxygen-compatible materials per CGA G-4.1 guidelines. The control electronics meet IEC 61000-6-3 (EMC emission) and IEC 61000-6-2 (immunity) requirements. While not intrinsically safe, the unit is intended for installation in non-hazardous laboratory zones under ISO 14644-1 Class 8 cleanroom conditions or equivalent.
Software & Data Management
The 2755-25 operates as a standalone hardware controller without embedded firmware or digital interface ports. It delivers analog status outputs (0–10 V DC) for high/low level alerts and a relay-based dry-contact signal for external logging or PLC integration. For traceability in regulated environments (e.g., GLP/GMP-compliant lyophilizer suites), users may connect the relay output to a validated data acquisition system supporting 21 CFR Part 11 audit trails. No onboard memory or software updates are provided—configuration is fixed at factory. Calibration verification is performed annually using certified LN₂ level reference gauges per ASTM E2877-22 (Standard Guide for Cryogenic Level Measurement).
Applications
- Continuous-duty rotary evaporators requiring stable –196 °C cold trap temperatures during multi-hour solvent removal
- Pharmaceutical lyophilization pre-condensers where consistent ice capacity directly impacts primary drying rate and product cake morphology
- Vacuum manifold systems for parallel sample concentration, where uniform LN₂ availability prevents differential condensation and cross-contamination
- Research-scale molecular distillation setups operating under <10⁻³ mbar, where cold trap efficiency determines volatile fraction recovery yield
- Environmental analysis instrumentation (e.g., purge-and-trap GC-MS) requiring uninterrupted cryofocusing without operator presence
FAQ
Does the 2755-25 support remote monitoring or Ethernet connectivity?
No. The system provides only hardwired analog and relay outputs for integration into third-party SCADA or DAQ platforms.
Can the 25 L LN₂ tank be replaced with a larger external dewar?
Yes—via custom adapter fitting—but doing so voids factory calibration and requires revalidation of sensor response curves.
Is the SL29GL-A cold trap included with thermal insulation?
No. The glass trap is supplied bare; users must install optional vacuum-jacketed sleeves or reflective foil wraps for thermal efficiency optimization.
What maintenance intervals are recommended for the solenoid valve and level sensors?
Valve actuation life is rated for ≥100,000 cycles; sensors require annual cleaning with anhydrous ethanol and visual inspection for frost-induced microcracks.
Does this system comply with FDA 21 CFR Part 11 for electronic records?
The unit itself does not generate or store electronic records. Compliance depends entirely on the external system receiving its relay/analog signals and implementing appropriate audit-trail functionality.
