Faq

Norhof develops, produces, and distributes a wide range of liquid nitrogen (LN2) dosing systems, focusing on innovation, quality, and close customer contact for over 40 years

Norhof systems are used for filling FTIR detectors, SEM, TEM or FIB microscopes, cold traps, cryogenic electron microscopes, DSC and other laboratory and industrial applications where precise, safe, and clean LN2 dosing is required

Norhof offers both manual and automatic LN2 dosing systems:
Manual systems: For safe, hand-controlled administration of LN2 in small vessels
Automatic systems: Programmable microdosing with various control options, including level and temperature-based modes, remote control, and data logging

The pump creates a gentle overpressure (up to 300 mBar) in the Dewar by heating a small amount of LN2, causing the liquid to rise and flow out without the need for high pressure or solenoid valves. This ensures quiet, spill-free, and precise LN2 delivery

No need for high-pressure vessels or solenoid valves
Minimal risk of ice formation in the Dewar
Quiet, vibration-free operation
Adjustable and precise flow rates
Enhanced safety and compliance with laboratory standards

Norhof offers lightweight, robust aluminum Dewars in various sizes (e.g., 35L, 50L, 100L), all equipped for easy LN2 withdrawal and transport

Yes, Norhof’s automatic systems can be controlled remotely via software, PLCs, or computers, and support multiple control modes for seamless integration into automated laboratory setups

Certain models, such as the #915, can also be used for liquid argon dosing. Please contact Norhof for specific requirements

Contact Norhof directly via email (info@norhof.com) or phone (+31 – 85 – 1045715) for support, custom solutions, or further technical information

Manual pumps: Up to 1 liter/minute
Automatic pumps: Adjustable from a few drops up to 0.5 liters/minute

Yes, the systems are designed for safe use inside laboratories, near workspaces, thanks to their low-pressure operation and compliance with safety standards

Norhof LN2 microdosing systems offer unattended, automatic refilling of FTIR and laser detectors, ensuring consistent cooling and minimizing downtime. The system can be programmed for overnight measurements and automatic sequences, making it ideal for laboratories that require reliable, hands-off operation

Yes, Norhof provides standard adaptors for brands like Bruker and Shimadzu, and custom adaptors are available on request for other detector types, ensuring compatibility with a wide range of scientific instruments

They allow safe, precise, and spill-free hand-controlled or automatic filling of small Dewars, samples, or experimental setups. The low-pressure, microdosing approach reduces risks, noise, and LN2 waste, making daily use practical and safe at the workstation

Filling small Dewars or containers for experiments
Cooling small objects or chemical reactions
Freezing small samples
Filling Dry Shippers for sample transport
For Automated Laboratory Workflows

The automatic LN2 microdosing pumps can be remotely controlled via software or PC, support multiple level and temperature control modes, and offer monitoring and data logging. This enables seamless integration into automated laboratory processes, such as unattended overnight measurements or scheduled sample cooling

Yes, the hand-controlled systems are ideal for safely and efficiently filling Dry Shippers with LN2, ensuring proper sample preservation during transport without the risks of overfilling or spillage

Absolutely. The precise, low-flow dosing is perfect for controlled cooling of small-scale chemical reactions or delicate objects, minimizing thermal shock and LN2 waste

Gentle, pressureless LN2 delivery
Adjustable and programmable flow rates
Minimal risk of spillage, noise, and vibration
Enhanced safety for laboratory personnel
Compatibility with a wide range of scientific and industrial equipment
If you have a specific application in mind, please contact Norhof for tailored advice and solutions.

The Norhof LN2 microdosing system is designed for precise, safe, and automated dispensing of liquid nitrogen (LN2) in a wide range of laboratory and industrial settings. Its main applications include:
Filling Cold Traps in Vacuum Systems
Automated or manual filling of cold traps to maintain optimal vacuum conditions in scientific and industrial processes2.
Filling Biological Storage Vessels
Controlled LN2 delivery for cryogenic storage of biological samples, ensuring consistent temperatures and minimizing sample loss2.
FTIR Detector Refilling
Automatic, gentle refilling of FTIR detectors (e.g., Bruker, Shimadzu) to enable uninterrupted, overnight, or long-duration measurements without operator intervention8.
DSC (Differential Scanning Calorimeter) Filling
Fully automatic, slow filling of DSC systems to maintain precise cooling during measurements, eliminating the need for manual refills and improving operator safety7.
Filling Small Vessels and Dewars
Safe, spill-free filling of small laboratory vessels, Dewars, or samples, either manually or automatically, directly at the workstation6.
Hand-Controlled Cooling and Freezing
Manual administration of LN2 for cooling small objects, freezing small samples, or filling Dry Shippers for sample transport6.
Temperature-Controlled Applications
Precise LN2 dosing for temperature stages in microscopes, thermal analysis systems, gas chromatography, and sub-zero temperature control systems2.
Stopping Chemical Reactions
Controlled cooling to rapidly halt chemical reactions at specific process stages2.
Cooling of Targets, IR Cells, and Cuvettes
Microdosing LN2 to cool sensitive components in research and analytical instruments2.
Computer-Controlled Freezing and Automated Laboratory Workflows
Integration with laboratory automation systems for remote-controlled, programmable LN2 dosing, including software monitoring and data logging12.
These applications benefit from Norhof’s pressure-less, spill-free, and vibration-free LN2 delivery, which enhances safety, precision, and workflow efficiency in laboratory environments

Yes. Norhof regularly ships products worldwide. All systems are carefully packaged to meet international shipping standards, and documentation is provided for customs clearance.

Yes. Norhof LN2 systems are available in versions compatible with both 110V and 230V power supplies, and come with the appropriate plug type for your country upon request.

User manuals are provided in English. Additional languages may be available upon request. Technical support is primarily offered in English.

Absolutely. Norhof offers remote technical support via email, phone, and video conferencing. Our team can assist with installation, troubleshooting, and application advice regardless of your location.

Norhof systems comply with relevant European safety and quality standards, such as the CE mark. Please contact us if you require region-specific certifications or documentation.

Customs duties, import taxes, and any local fees are the responsibility of the customer. Norhof provides all necessary commercial invoices and shipping documents to facilitate smooth customs clearance.

Yes. Norhof systems are designed to be compatible with a wide range of laboratory instruments worldwide. Adaptors for major brands (e.g., Bruker, Shimadzu) are available, and custom solutions can be provided on request.

Lead times vary depending on the product and destination, but most orders are shipped within 2–4 weeks. You will receive an estimated delivery date upon order confirmation.

Yes. Norhof provides remote training sessions and detailed user manuals to ensure correct installation and operation. On-site training may be available in select regions—please inquire for details.

Contact Norhof directly via email (info@norhof.com) or phone (+31 – 85 – 1045715). Our team will guide you through the ordering process, provide a quote, and arrange shipping to your location.

Norhof systems are engineered for high reliability, using a static pump design with minimal moving parts. This reduces the risk of mechanical failure and ensures consistent performance over time. The systems are ready for use 24 hours a day and deliver LN2 on demand, with no need for warm-up or priming.

Thanks to the robust design and use of pressure-less Dewars, Norhof systems typically offer a long operational lifetime. The lack of high-pressure components, solenoid valves, or complex control instruments minimizes wear and tear, contributing to extended service life.

Routine maintenance is minimal. Periodic checks should be performed on Dewar seals, fill hoses, and electrical connections. Keeping the system clean and dry, and regularly inspecting for condensation or frost buildup, will help maintain optimal performance and extend equipment life. Dewar vessels should be checked for integrity and venting, and any worn parts should be replaced as needed.

The static pump design eliminates common failure points found in systems with solenoid valves or high-pressure fittings. There are no internal LN2 valves or external control valves that could fail, reducing downtime and maintenance needs.

Norhof systems use insulated tubing and have a low thermal mass, which means there is minimal heat transfer and rapid LN2 delivery. This design reduces ice buildup and thermal stress, helping maintain high filling efficiency (over 90%) throughout the system’s lifetime.

If service is needed, Norhof provides technical support and replacement parts. Most issues can be resolved by replacing consumables or performing minor repairs, thanks to the system’s modular and accessible design.