Frequently asked questions to Cryogenic Services;
For "in-house" questions.
For "out-house" questions.

1.- Which dewar should I use?
2.- Can you teach me how to transfer?
3.- What's that awful smell?
4.- Why are you bothering me?
5.- I feel like you guys are watching me all the time? What gives?
6-. Why can't I take a dewar at 9 am weekdays?
7.- Why does my cryostat keep plugging?
8.- Why can't I keep a dewar in my lab?
9.- Why must I return empty gas cylinders when I take a full one?
10.- What's the best way to request liquid helium? cylinder gasses?
11.- Why is Cryogenic Services' door closed during business hours?
12-. Where do I get liquid nitrogen?
13.- What's the best way to get cylinder gasses?

Questions asked from people not associated with the University of Florida;
1.- What Helium Liquefier do you have?
2.- How much helium do you produce? per year?, per month?, per day?, per hour?
3.- How much helium gas do you recover?
4.- How do you measure impurities?
5.- Do you recover helium from remote labs?
6.-How many people use helium at UF?
 
 

1.- Which dewar should I use?

A: Most dewars are shared. If you are not speciffically assigned a dewar, you should use the one with the lowest liquid level from which you can get a complete transfer. Assigned dewars are labelled in the NPB or are noted on the dewar room entrance door in CLB or on the whiteboard in the hallway of Williamson for the Microkelvin Lab and Williamson users. An email from Cryogenic Services is the most definitive.
2.- Can you teach me how to transfer?
A: The primary responsibility for all training in individual labs is with the PI  for that lab. However, we are more than willing to train lab personel in the proper methods of helium transfer.
3.- What's that awful smell?
A: In each lab is a water drain. After long periods of no use, they dry out and allow sewer gasses to enter the lab. Pour at least one gallon of water into the drain and the odor should diminish rapidly. It will smell like a natural gas leak. If the odor does not go away and you think it may be an actual gas leak, leave the area and call 2-1111.
4.- Why are you bothering me?
A: We are not bothering you. We are here to help you. If you play by our rules, you will be happier. We will be happier and your PI will be happier because his bills will be lower.
5.- I feel like you guys are watching me all the time? What gives?
A: In a sense, we are watching you all the time. We have a data gathering system called the Cryonet which allows us to monitor all aspects of the liquid helium and recovery resources, including monitors in your lab. If we notice any anomallies we dispatch immediately to prevent small problems from becoming dangerous or large expensive problems. In the Cryogenic Services area, we have several cameras for monitoring the activity within, including the dewar storage room, so that we can assure visitors' safety and dewar assignment compliance.
6-. Why can't I take a dewar at 9 am weekdays?
Every morning at 9 am, the system of computers and data acquisition boxes, know as the Cryonet, poll every helium dewar and gasmeter for a daily inventory and for the previous days' helium usages. If a dewar is not plugged into the network, its data will be missing for that day and disrupts the ability to accurately take an inventory. The daily inventory is a very important method to asses the sysytems' worthyness and to keep the cost of helium low.
7.- How come your dirty helium makes my cryostat plug up?
A: Most plugs are caused by sloppy procedures in the lab, however, we made a supply of transfer tube filters that each lab can have free of charge to reduce the chances that "dirty" helium can cause a plug. The root cause of dirty helium, is sloppy procedures in the lab that contaminate the transport dewars.
8.- Why can't I keep a dewar in my lab?
A: To reduce the cost of having an in house helium system, we share transport dewars to reduce the total number of dewars we need and to maximize the efficient usage of the ones in use. If a dewar is stored in the lab when not in use, it costs everyone more money and inconvienences the other labs who need helium.
9.- Why must I return empty gas cylinders when I take a full one?
A: The rental fees on cylinders can be more than the cost of the product in the cylinder. We provide cylinders and the gas in them at no cost to the labs. So you have no reason to complain.
10.- What's the best way to request liquid helium?
A: On the web here, Email, on the clipboard sign out sheets, phone, in-person - in that order.
11.- Why is Cryogenic Services' door closed during business hours?
A: Since there are only two staff members there are frequently times that we are both needed outside the Cryogenic Services area, for helium deliveries and maintenence demands. For everyone's safety, no one is allowed into the Cryogenic Services area without one of us here.
12-. Where do I get liquid nitrogen?
A: To fill lab supply dewars, there is a fill port on the loading dock of the NPB, and in the hallway of Williamson. For academic liquid nitrogen or for small infrequent needs a 160 liter storage dewar is located in the Helium dewar storage room B123. All liquid nitrogen fills should be logged on the computer in the fill station area. You should be trained by your PI or us before ever attempting to get liquid nitrogen on your own.
13.- What's the best way to get cylinder gasses?
A: There is a request form in B123 for cylinder gasses. Or you can ask one of us in person. Helium cylinders are stocked in B123. Nitrogen and Argon and most other common gases can be ordered within a day or two. If you need Special and/or high purity gasses, you should plan ahead, allowing for up to a month to receive them.
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Questions asked from people not associated with the University of Florida;

1.- What Helium Liquefier do you have?

A: Process Systems International 1610-AS with a single RS compressor installed in 1994. Prior to that we had an Air Products Helifier installed in 1980 and before that an ADL Collins Liquefier installed in 1958.
2.- How much helium do you produce? per year?, per month?, per day?, per hour?
A: We don't keep track of production because there is no easy way to get an accurate rate. What we track is the amounts used by the labs. Production can be 20-40% higher. We have a web area devoted to usage. See reports, annual graph, monthly graph, and our liquefier produces about 50 liters per hour while running 2-5 days per week.
3.- How much helium gas do you recover?
A: System wide, Roughly 90%. The majority of labs recover 95% or better. But we have 4 labs that we supply helium to that are not on recovery. They pay a premium, but it still costs them less than commercial helium would.
4.- How do you measure impurities?
A: We use two GOW-MAC 20-260 Air in Helium purity monitors, and a Kahn Hygrometer. The devices are the best money you will ever spend on a helium recover system. Both are connected to a chart recorder to look for trends. Trends are way more informative than the instantaneous ones.
5.- Do you recover helium from remote labs?
A: Yes, we have recovery extended to 7 remote buildings up to one mile away by using custom built UF designed, low pressure recovery systems.
6.- How many people use helium at UF?
A: We serve Physics, Chemistry, The McKnight Brain Institute, Material Sciences, Astronomy and Geology with about 42 seperate individual labs with one to many people in each one.
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