• We perform Cryofills daily at universities, hospitals, pharmaceutical companies and government research labs across the USA.
• MR Resources maintains all of your fill scheduling so you don't have to.
• Our NMR Fill Technicians have many years of experience in all aspects of NMR magnet filling procedures.

How many times have you been attempting to fill your magnet with Liquid Helium and you were unsure if you were doing it correctly?
Is my magnets current Liquid Helium level at a point where the coil is partially exposed?
What do I do differently if it is?
Am I filling it too fast…or too slow?
Is the pressure in the dewar where it's supposed to be for my particular type of magnet?
What do I do if the fill line goes "soft" while I'm doing a fill?
You may not know all the answers to these important questions. This much is true: if the magnet is not filled in the proper manner it will quench causing significant "down time" for your lab, not to mention the exorbitant costs associated with bringing the magnet back up to field. What would it be worth to your lab to not have to worry about such issues? MR Resources can take the responsibility of properly filling your NMR Magnet so you don't have to. You are trained to do analysis & experiments utilizing your spectrometer. We are trained to take care of ALL aspects regarding your NMR system. MR Resources' Helium Fill Contracts allow you to do your work, while MR Resources does ours. Our engineers will look at your magnets specifications and arrange the proper scheduling to come to your lab and fill your magnets with Liquid Helium, thus both assuming responsibility for the proper filling of your magnets and freeing up your time to do your lab work.

• Our 1-800-4 HELIUM telephone number, makes placing orders convenient and cost free.
• All orders are dispatched from one central location to our 12 regional supply points to assure superb quality control.
• Start-up and Emergency delivery services available.
• Our cryogens meet or excede recommended purity specifications.

"I would like to compliment MR Resources on nearly five years of fine service to Oxford Instruments. Over these past five years I have been involved with installation and service for superconducting magnet systems around the country. During this period MR Resources' Liquid Helium deliveries have always been on time, regardless of the quantity ordered or it's destination. Thank you all for making a positive contibution to Oxford Instruments needs."
Newell Tillman, Customer Support Manager Oxford Instuments America, Inc., Superconductivity Division

"We have been purchasing our liquid helium through MR Resources for over a decade. Prior to MR Resources becoming our supplier we had many unpleasant experiences trying to obtain liquid helium. In one instance we received a non-stainless steel dewar which became stuck to a wide-bore 300 MHz magnet. With MR Resources, one phone call to 800-4-HELIUM takes care of everything where as before we sometimes had the aggravation of filling out two separate purchase orders, one for the liquid helium and one for the delivery charges. No one has been able to beat the cost of liquid helium from MR Resources either. Reliability is the best feature of obtaining liquid helium from MR Resources, we know that MR Resources will get the dewar to us within our needed timeframe."
David Weisleder, NMR Spectroscopist at the USDA National Center for Agricultural Utilization Research

"I would like to express my appreciation to you and the Cryogens Department at MR Resources for the excellent service delivered over the past year. Ordering is simple and efficient. Deliveries are accurate and on time. You and MR Resources have been extremely helpful by taking the time to answer questions and offer advice on ways to improve the care and maintenance of our NMR system."
John Havard, Ciba Specialty Chemicals, McIntosh Alabama

"I would like to express my appreciation to MR Resources group for their excellent cryogens support. MR Resources has provided ONI with cryogen delivery from coast to coast and in several instances saved us costly delays by providing emergency delivery services. As a new player in the MRI market ONI has found MR Resources support and expertise in cryogens invaluable."
Bob Stevens, ONI, Inc.

• Liquid nitrogen is typically filled every 7 to 10 days and depending on your type of magnet, liquid helium fills can be required as often as once a month to as infrequently as only once or twice per year.
• Cryogen fills must be performed correctly to avoid injury to you and the magnet.
• Injury to a magnet could include breaking a seal on a dewar or quenching a magnet.
• Both forms of magnet injuries are repairable, but at the least entail recharging the magnet; at the most, they can entail replacing the magnet.

• When filling the magnet with liquid nitrogen, you must be sure not to exceed the recommended fill pressure and rate for your magnet.
• If your magnet has two liquid nitrogen ports, one should be used for filling and the other for venting the boil-off gaseous nitrogen and overfill liquid nitrogen.
• A piece of tubing is typically placed on the vent port to direct the overfill liquid nitrogen away from the magnet seals, probe, and electronics.
• It is highly recommended that your liquid nitrogen tanks be made of non-magnetic stainless steel.
• Liquid helium fills are typically a awkward operation. Because they are done so infrequently, it is good to review the process before each fill.
• The fill requires a supply dewar of liquid helium, a special liquid helium transfer line, and a tank of pure compressed helium gas.
• Liquid helium is transferred from the liquid helium supply dewar up through the transfer line, into the helium dewar of the magnet.
• The transfer line goes into the top of the liquid helium supply dewar, but should never rest on the bottom of the dewar.
• The bottom of the dewar may contain frozen water, oxygen, and nitrogen which will be forced into your magnet if the transfer line touches the bottom during the transfer process.
• The compressed helium gas, mentioned earlier, is for pressurizing the liquid helium supply dewar with about 2 to 4 psi of pressure.
• Gauges on helium supply dewars can be very inaccurate, so do not count on them to give you an accurate reading.
• A helium pressure above the liquid forces the Helium into the magnet dewar.
• The transfer line is usually inserted into the magnet until it contacts a transfer flange in the bottom of the magnet.
• The nitrogen ports on the magnet should be plugged with a check valve during filling of the helium dewar of the magnet.
• This step prevents cryopumping, a process whereby nitrogen, water, and oxygen are condensed out of the atmosphere into the nitrogen dewar due to the magnet stacks being cooled by the helium.
• Many labs loosely plug the helium vents with tissue during the fill. This cuts down on cryopumping should the flow of the venting He drop.
• The best way to determine if the magnet is full is to look for a change in the gas cloud coming out of the magnet vents.
• When the magnet is full the cloud becomes very thick with a deep white center plume with a slight blue tint.
• The helium vents on the magnet should be closed promptly after the magnet is full.