- •Contents
- •Foreword
- •Preface
- •1 Materials in the Lab
- •2 Measurement
- •3 Joints, Stopcocks, and Glass Tubing
- •4 Cleaning Glassware
- •5 Compressed Gases
- •6 High and Low Temperature
- •7 Vacuum Systems
- •8 The Gas-Oxygen Torch
- •APPENDIX
- •Appendix A Preparing Drawings for a Technician
- •Index
- •Foreword
- •Preface
- •For the Second Edition
- •Please note:
- •1 Materials in the Lab
- •1.1 Glass
- •1.1.1 Introduction
- •1.1.2 Structural Properties of Glass
- •1.1.3 Phase Separation
- •1.1.4 Devitrification
- •1.1.5 Different Types of Glass Used in the Lab
- •1.1.6 Grading Glass and Graded Seals
- •1.1.7 Separating Glass by Type
- •1.1.9 Stress in Glass
- •1.1.11 Tempered Glass
- •1.1.13 Limiting Broken Glass in the Lab
- •1.1.14 Storing Glass
- •1.1.15 Marking Glass
- •1.1.16 Consumer's Guide to Purchasing Laboratory Glassware
- •1.2 Flexible Tubing
- •1.2.1 Introduction
- •1.2.2 Physical Properties of Flexible Tubing
- •1.3 Corks, Rubber Stoppers, and Enclosures
- •1.3.1 Corks
- •1.3.2 Rubber Stoppers
- •1.3.3 Preholed Stoppers
- •1.3.4 Inserting Glass Tubing into Stoppers
- •1.3.5 Removing Glass from Stoppers and Flexible Tubing
- •1.3.6 Film Enclosures
- •1.4 O-Rings
- •1.4.2 Chemical Resistance of O-Ring Material
- •1.4.3 O-Ring Sizes
- •2 Measurement
- •2.1 Measurement: The Basics
- •2.1.1 Uniformity, Reliability, and Accuracy
- •2.1.2 History of the Metric System
- •2.1.3 The Base Units
- •2.1.4 The Use of Prefixes in the Metric System
- •2.1.5 Measurement Rules
- •2.2 Length
- •2.2.1 The Ruler
- •2.2.2 How to Measure Length
- •2.2.3 The Caliper
- •2.2.4 The Micrometer
- •2.3 Volume
- •2.3.1 The Concepts of Volume Measurement
- •2.3.2 Background of Volume Standards
- •2.3.4 Materials of Volumetric Construction #1 Plastic
- •2.3.5 Materials of Volumetric Construction #2 Glass
- •2.3.6 Reading Volumetric Ware
- •2.3.7 General Practices of Volumetric Ware Use
- •2.3.8 Calibrations, Calibration, and Accuracy
- •2.3.9 Correcting Volumetric Readings
- •2.3.10 Volumetric Flasks
- •2.3.11 Graduated Cylinders
- •2.3.12 Pipettes
- •2.3.13 Burettes
- •2.3.14 Types of Burettes
- •2.3.15 Care and Use of Burettes
- •2.4 Weight and Mass
- •2.4.1 Tools for Weighing
- •2.4.2 Weight Versus Mass Versus Density
- •2.4.3 Air Buoyancy
- •2.4.5 Balance Location
- •2.4.6 Balance Reading
- •2.4.7 The Spring Balance
- •2.4.8 The Lever Arm Balance
- •2.4.9 Beam Balances
- •2.4.10 Analytical Balances
- •2.4.11 The Top-Loading Balance
- •2.4.12 Balance Verification
- •2.4.13 Calibration Weights
- •2.5 Temperature
- •2.5.1 TheNature of Temperature Measurement
- •2.5.2 The Physics of Temperature-Taking
- •2.5.3 Expansion-Based Thermometers
- •2.5.4 Linear Expansion Thermometers
- •2.5.5 Volumetric Expansion Thermometers
- •2.5.7 Thermometer Calibration
- •2.5.8 Thermometer Lag
- •2.5.9 Air Bubbles in Liquid Columns
- •2.5.10 Pressure Expansion Thermometers
- •2.5.11 Thermocouples
- •2.5.12 Resistance Thermometers
- •3.1 Joints and Connections
- •3.1.1 Standard Taper Joints
- •3.1.2 Ball-and-Socket Joints
- •3.1.3 The O-Ring Joint
- •3.1.4 Hybrids and Alternative Joints
- •3.1.5 Special Connectors
- •3.2 Stopcocks and Valves
- •3.2.1 Glass Stopcocks
- •3.2.2 Teflon Stopcocks
- •3.2.3 Rotary Valves
- •3.2.4 Stopcock Design Variations
- •3.3.1 Storage and Use of Stopcocks and Joints
- •3.3.2 Preparation for Use
- •3.3.3 Types of Greases
- •3.3.4 The Teflon Sleeve
- •3.3.5 Applying Grease to Stopcocks and Joints
- •3.3.6 Preventing Glass Stopcocks and Joints from Sticking or Breaking on a Working System
- •3.3.7 Unsticking Joints and Stopcocks
- •3.3.8 Leaking Stopcocks and Joints
- •3.3.9 What to Do About Leaks in Stopcocks and Joints
- •3.3.10 General Tips
- •3.4 Glass Tubing
- •3.4.1 The Basics of Glass Tubing
- •3.4.2 Calculating the Inside Diameter (I.D.)
- •3.4.3 Sample Volume Calculations
- •4 Cleaning Glassware
- •4.1 The Clean Laboratory
- •4.1.1 Basic Cleaning Concepts
- •4.1.2 Safety
- •4.1.3 Removing Stopcock Grease
- •4.1.4 Soap and Water
- •4.1.5 Ultrasonic Cleaners
- •4.1.6 Organic Solvents
- •4.1.7 The Base Bath
- •4.1.8 Acids and Oxidizers
- •4.1.9 Chromic Acid
- •4.1.10 Hydrofluoric Acid
- •4.1.11 Extra Cleaning Tips
- •4.1.12 Additional Cleaning Problems and Solutions
- •4.1.13 Last Resort Cleaning Solutions
- •5 Compressed Gases
- •5.1 Compressed GasTanks
- •5.1.1 Types of Gases
- •5.1.2 The Dangers of Compressed Gas
- •5.1.3 CGA Fittings
- •5.1.4 Safety Aspects of Compressed Gas Tanks
- •5.1.5 Safety Practices Using Compressed Gases
- •5.1.6 In Case of Emergency
- •5.1.7 Gas Compatibility with Various Materials
- •5.2 The Regulator
- •5.2.1 The Parts of the Regulator
- •5.2.2 House Air Pressure System
- •5.2.4 How to Use Regulators Safely
- •5.2.6 How to Purchase a Regulator
- •6 High and Low Temperature
- •6.1 High Temperature
- •6.1.1 TheDynamics of Heat in the Lab
- •6.1.2 General Safety Precautions
- •6.1.3 Open Flames
- •6.1.4 Steam
- •6.1.5 Thermal Radiation
- •6.1.6 Transfer of Energy
- •6.1.7 Hot Air Guns
- •6.1.8 Electrical Resistance Heating
- •6.1.9 Alternatives to Heat
- •6.2 Low Temperature
- •6.2.1 TheDynamics of Cold in the Lab
- •6.2.2 Room Temperature Tap Water (=20°C)
- •6.2.8 Safety with Slush Baths
- •6.2.9 Containment of Cold Materials
- •6.2.10 Liquid (Cryogenic) Gas Tanks
- •7 Vacuum Systems
- •7.1 How to Destroy a Vacuum System
- •7.2.1 Preface
- •7.2.2 How to Use a Vacuum System
- •7.2.4 Pressure, Vacuum, and Force
- •7.2.5 Gases, Vapors, and the Gas Laws
- •7.2.6 Vapor Pressure
- •7.2.7 How to Make (and Maintain) a Vacuum
- •7.2.8 Gas Flow
- •7.2.9 Throughput and Pumping Speed
- •7.3 Pumps
- •7.3.1 The Purpose of Pumps
- •7.3.2 The Aspirator
- •7.3.3 Types and Features of Mechanical Pumps
- •7.3.4 Connection, Use, Maintenance, and Safety
- •7.3.5 Condensable Vapors
- •7.3.6 Traps for Pumps
- •7.3.7 Mechanical Pump Oils
- •7.3.8 The Various Mechanical Pump Oils
- •7.3.9 Storing Mechanical Pumps
- •7.3.11 Ultra-High Vacuum Levels Without Ultra-High
- •7.3.12 Diffusion Pumps
- •7.3.13 Attaching a Diffusion Pump to a Vacuum System
- •7.3.14 How to Use a Diffusion Pump
- •7.3.15 Diffusion Pump Limitations
- •7.3.17 Diffusion Pump Maintenance
- •7.3.18 Toepler Pumps
- •7.4 Traps
- •7.4.1 The Purpose and Functions of Traps
- •7.4.2 Types of Traps
- •7.4.3 Proper Use of Cold Traps
- •7.4.4 Maintenance of Cold Traps
- •7.4.5 Separation Traps
- •7.4.6 Liquid Traps
- •7.5 Vacuum Gauges
- •7.5.2 The Mechanical Gauge Family
- •7.5.4 The Liquid Gauge Family
- •7.5.5 The Manometer
- •7.5.6 The McLeod Gauge
- •7.5.7 How to Read a McLeod Gauge
- •7.5.8 Bringing a McLeod Gauge to Vacuum Conditions
- •7.5.10 The Tipping McLeod Gauge
- •7.5.11 Condensable Vapors and the McLeod Gauge
- •7.5.12 Mercury Contamination from McLeod Gauges
- •7.5.13 Cleaning a McLeod Gauge
- •7.5.14 Thermocouple and Pirani Gauges
- •7.5.15 The Pirani Gauge
- •7.5.16 Cleaning Pirani Gauges
- •7.5.17 The Thermocouple Gauge
- •7.5.18 Cleaning Thermocouple Gauges
- •7.5.19 The lonization Gauge Family
- •7.5.20 The Hot-Cathode Ion Gauge
- •7.5.21 Cleaning Hot-Cathode Ion Gauges
- •7.5.24 The Momentum Transfer Gauge (MTG)
- •7.6 Leak Detection and Location
- •7.6.1 AllAbout Leaks
- •7.6.3 False Leaks
- •7.6.4 Real Leaks
- •7.6.5 Isolation to Find Leaks
- •7.6.6 Probe Gases and Liquids
- •7.6.7 The Tesla Coil
- •7.6.8 Soap Bubbles
- •7.6.9 Pirani or Thermocouple Gauges
- •7.6.10 Helium Leak Detection
- •7.6.11 Helium Leak Detection Techniques
- •7.6.13 Repairing Leaks
- •7.7 More Vacuum System Information
- •7.7.1 The Designs of Things
- •8 The Gas-Oxygen Torch
- •8.1.2 How to Light a Gas-Oxygen Torch
- •8.1.3 How to Prevent a Premix Torch from Popping
- •8.2.2 How to Tip-Off a Sample
- •8.2.3 How to Fire-Polish the End of a Glass Tube
- •8.2.4 Brazing and Silver Soldering
- •Appendix
- •A.2 Suggestions for Glassware Requests
- •B.1 Introduction
- •B.2 Polyolefins
- •B.3 Engineering Resins
- •B.4 Fluorocarbons
- •B.5 Chemical Resistance Chart
- •C.1 Chapter 1
- •C.4 Chapter 4
- •C.5 Chapter 5 & Chapter 6
- •C.6 Chapter 7
- •C.7 Chapter 8
- •D.1 Laboratory Safety
- •D.2 Chemical Safety
- •D.3 Chapter 1
- •D.4 Chapter 2
- •D.5 Chapter 3
- •D.6 Chapter 4
- •D.7 Chapter 5 and the Second Half of Chapter 6
- •D.8 Chapter 7
- •D.9 Chapter 8
- •Index
More Vacuum System Information 7.7 |
467 |
Fig. 7.66 Removing a hole from a glass seal by removing the glass around the hole with a glass rod and a gas-oxygen torch (not shown).
lated circumstances, covering a hole with Glyptol or any other temporary patch should not be relied on because:
1.There is a chance that you may create a virtual leak.
2.Once a system is (temporarily) repaired, there is a good chance that the need for a permanent repair will drop ("out of sight, out of mind"). Temporary repairs are, at best, temporary and should not be relied on for future needs.
3.Glyptol, or other temporary leak repair material, can be very difficult to properly remove from a glass surface. Total removal of any temporary sealant must be done before any glassworking can be done.
Obviously there will be times when the temporary repair of a leak is essential, but otherwise it is best to make all repairs permanent.
After a leak has been discovered and removed and the glass repaired, flameannealed, and cooled, the system must be leak checked again not only to verify that the repair was successful, but to see if there are any other leaks that need repair. It is not uncommon for another leak to be immediately adjacent to the first leak. An adjacent, smaller may be unable to attract the spark from a Tesla coil away from a larger leak. Or, a larger leak can cause too much helium noise for a smaller leak to be pinpointed. However, once larger leaks are repaired, smaller leaks can be more readily identified.
7.7 More Vacuum System Information
7.7.1The Designs of Things
As you work with vacuum systems, you may be called upon to design new parts and/or sections for the system. Your success will depend on your experience with the materials you select, your choice of materials, and your access to experienced technicians.
468 Vacuum Systems
If you require metal components on your vacuum system, select metals with low gas permeation, such as 300 series stainless steel. It is nonmagnetic and, like glass, is a poor conductor of heat and electricity. Stainless steel, also like glass, is relatively nonreactive, and therefore is less likely to rust or be affected by chemicals. If welding the stainless steel is required, select 304L stainless steel, which is low in carbon. Otherwise, at welding temperatures the carbon will combine with the chromium (within the stainless steel) to form chromium carbide and the corrosion protection of the chromium will be lost. Type 303 stainless steel should not be used for vacuum work because it contains selenium, which has a high vapor pressure.
The metals zinc and cadmium should be avoided because of their high vapor pressures. Metals that include zinc and cadmium alloys such as brass (copper and zinc) and some silver solders (cadmium) should also be avoided for the same reasons. It is possible to obtain cadmium-free silver solder and brazing materials that use tin, lead, and indium for vacuum use. Some steel screws are cadmium-coated and also must be avoided.
Copper is often used as gasket material, such as in Conftat (Varian) flanges, however, standard copper is often permeated with oxygen. If copper is heated in a hydrogen environment, the oxygen combines with the hydrogen to form water, which causes the copper to become brittle. Thus, when selecting copper, obtain OFHC (oxygen-free high-conductivity) copper.
Besides copper, indium is often used as a metal gasket material. Despite its lack of elasticity and its limited operating temperature (100°C), indium wire (0.8 - 1.6 mm) can easily be bent into a circle of any desired size and, if the ends are overlapped, no soldering is required. Aluminum can be made into a gasket as well by using a wire (0.5 - 1 mm), bending it into a circle of the desired size, and soldering it together using a flux. The flux must be washed off before use. Aluminum can be used to temperatures as high as 400°C. Gold is probably the best material for gaskets because it requires no flux to join the ends of a circled wire and can be used to temperatures as high as 450-500°C.
Parts are fairly easy to attach and change with metal systems; it is mostly a matter of unbolting one unit and replacing it with another. Be sure to follow the bolting techniques described in Sec. 7.6.4 to ensure even cutting on gaskets and equal torque on flange surfaces.
Glass systems are a little different: If you have not worked with glass before, do not try to learn glassblowing on an already made vacuum system. If you want to learn some glassblowing techniques, it is imperative that you start with small items at a bench before risking the destruction of a very valuable piece of equipment. Watching an experienced glassblower is deceiving because it looks easy. A concert pianist makes playing piano look just as easy, but playing the piano is just as difficult.
This book is not an instruction book on glassblowing. Chapter 8 has some tips on gas-oxygen torch use, and Appendix D contains some recommended books for your consideration. The following discussion will also provide some of the
More Vacuum System Information 7.7 |
469 |
Fig. 7.67 Support on vacuum lines must be connected to the vertical bars of a support rack, not the horizontal bars.
dynamics of glass vacuum systems so that common errors and problems can be avoided. Consider the following questions before doing any glasswork and/or additions to a vacuum line:
Are the Glasses You Have to Work with Compatible (see Sec. 1.1.5)? Trying to repair a small leak in a vacuum line made of borosilicate glass by filling a hole with a soda-lime glass will result in an entire day of repair by a qualified person instead of the half-hour originally required.
Do Any of the Items Being Added onto the Vacuum System Have any Concave Surfaces? Convex items can support themselves against atmospheric forces with a vacuum on the other side. Concave-shaped items, on the other hand, cannot deal with the stress unless they have been specially built. For example, a standard Erlenmeyer flask cannot withstand atmospheric forces against a vacuum because the base is somewhat concave. However, a filter flask can withstand these pressures because it is constructed out of heavy-walled glass. There should be the same concern of implosion, whether a vacuum is created by a small single-stage vacuum pump or with a vacuum system capable of ultrahigh vacuum. The greatest percentage of change in force against an walls of a container occur when the item is brought from atmospheric to about 1 torr because the primary force at work is atmospheric pressure, not the vacuum. Remember, a vacuum of about 1 torr can pull water about 33 ft into the air, but no matter how much more vacuum is applied, the height of the water is raised a millimeter or so.
Fig. 7.68 If you tighten twoor three-fingered clamps or clamp supports (dark arrows), it is important to relieve the stress that is created on the glass by heating the connecting glass (hollow arrows).
470 |
Vacuum Systems |
Top view |
Side view |
Fig. 7.69 Placing cut rubber tubing on a support ring makes a good support for a round-bottom flask.
Are Your Vacuum Line Supports on Vertical or Horizontal Rods of the Vacuum Rack? Vacuum lines are supported by twoand/or three-fingered clamps, which in turn are held onto the vacuum rack by clamp supports that grip the rack by screws. Regardless of how tightly a clamp support is screwed down, it's not difficult to swing a support one way or another. This movement can be an advantage if you wish to swing away a support for a Dewar, but could be a disaster for a vertical axis support of a vacuum line (see Fig. 7.67). A disaster could also happen when an entire system or just a single item, is supported on horizontal bars.
Are Sections Between Vacuum Parts Breaking as You Tighten Twoand/or Three-Fingered Clamps or Clamp Supports? Glass is perfectly elastic until the point of fracture and it is easy to place too much torque against glass with the tightening screws of clamp fingers and/or clamp supports. During and/or after placing parts of a vacuum system in these devices, relieve the tension by heating the glass sections between the clamps (see Fig. 7.68). The heating should be done with a gentle, bushy flame. Be careful not to get the flame near larger-diameter tubing or near glass seals that could cause strain within the glass. These situations could cause later cracks or breaks.
Are There Rubber Cushions Supporting Round-Bottom Flasks on Support Rings? By simply taking pieces of rubber tubing and slitting them open along one side, protective surfaces are made on which to lay round-bottom flasks (see Fig. 7.69). This method of protection should not be used if a round-bottom flask is wanned greater than 100°C, or if you plan to heat the round-bottom flask in its support (see Sec. 1.1.9 for information on how to heat round bottom flasks). Such heating can burn or melt the rubber or vinyl tubing, releasing dangerous fumes.
Kevlar or glass wool tape
Fig. 7.70 Use Kevlar or glass wool tape on twoand three-fingered clamps, especially if they will be subjected to any heat.
More Vacuum System Information 7.7 |
471 |
Is There Fiberglass, Kevlar, or Ceramic Tape Protecting the Glass from Twoor Three-fingered Clamp Arms? When purchasing new twoor three-fin- gered clamps, they will be supplied with either a plastic coating or fiberglass covers on the fingers. Asbestos covers are no longer commercially available. The plastic provides protection for the glass, but cannot survive any significant heat or direct flames. It is possible to obtain fiberglass covers to replace the coverings on older twoand three-fingered clamps (see Fig. 7.70). Another choice for covering clamp fingers is Kevlar tubing. The advantage of Kevlar is that one size of tubing will fit many size fingers. The drawback is that Kevlar tubing unravels easy, so it should be limited to long-term holding and not used with clamps that are in constant (open and close) use. There are dipping solutions sold in hardware stores whereby you can provide your tool handles a plastic covering. These products can be used to place, or replace, the plastic on clamp fingers. Two to three coats have shown to provide an excellent coating. Be sure to use with adequate ventilation as they typically contain tolulene.
Are You Unable to Squeeze the Fingers of a Two-Fingered Clamp Down Sufficiently to Obtain a Good Grip on Small-Diameter Tubing? There are two choices to resolve this problem depending on the conditions surrounding the section of tubing in question. The easiest solution is to take a short piece of flexible tubing, slit open the side, and wrap this tubing piece around the glass tubing where the clamp will support the item. This slitting of the flexible tube is exactly the same process described in Fig. 7.69, except the slitted tube goes onto straight tubing instead of the support ring. If, on the other hand, the glass tubing will be heated, the piece of flexible tubing could be damaged. In these environments, wrap ceramic tape* (do not use asbestos tape) around the tubing that would otherwise be too narrow for a fingered clamp to obtain a firm grip (see Fig. 7.71).
Are You Snapping Stopcocks Off at the Base While Rotating the Plug?
Whenever possible, stopcocks should be supported from both ends by fusion to other glass and/or by a twoor three-fingered clamp, although this support cannot always be supplied. One of the purposes of an extra clamp is to provide support and bracing against the torque from accidental knocks. The main purpose of an extra stopcock is to protect it from heavy-handed rotation. As stopcock grease gets old, it becomes thicker and loses its slippery nature. When rotating a stopcock
Glass tubing with ceramic tape wraped around it
Fig. 7.71 Wrapping ceramic tape around glass tubing makes it easier to be held by twoor three-fingered clamps.
Ceramic tape can be obtained from the various glassblowing supply houses mentioned in Appendix C, for Sees. C.I.
472 |
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References |
^ ^ |
H |
Rotation of the |
|
Tension is created |
^ ^ - ^ ^ |
^ |
p l u f l |
here |
7 |
|
Torque iscreatedon |
yyj7// ^ |
|
||
the entire stopcock
Fig. 7.72 By rotating the stopcock plug without proper support, torque is created on the stopcock. If the tension is great enough, the stopcock may break.
plug with old grease, tremendous torque can be created on the stopcock and it can snap off at the base (see Fig. 7.72).
This breakage can be prevented by maintaining fresh stopcock grease in the stopcock and by holding the stopcock with one hand while rotating the plug with the other. In fact, it is always best to hold the body of a stopcock with one hand while rotating the plug with the other.
References
1.H.G.Tompkins, An Introduction to theFundamentals of Vacuum Technology,American Vacuum Society, American Institute of Physics, New York, 1984, p.2.
2.R.J. Naumann, "Prospects for a Contamination-Free Ultravacuum Facility in LowEarth Orbit," Journal of VacuumScience and Technology 7, 90-99 (1989).
3.J.F. O'Hanlon, A User's Guide to Vacuum Technology, Wiley-Interscience, John Wiley & Sons, New York, 1980, p. 11.
4.A. Guthrie, Vacuum Technology, Wiley-Interscience: John Wiley & Son, NewYork, 1963, p. 6.
5.T.E. Madey, "Early Applications of Vacuum, from Aristotle to Langmuir," Journal Vacuum Science and Technology,A, 2,110-117 (1984).
6.M.H.Hablanian, and B.B.Dayton, "Comments on the History of Vacuum Pumps,"
Journal Vacuum Science and TechnologyA, 2, 118-125 (1984).
7.J.H. Singleton, "TheDevelopment of Valves, Connectors andTraps forVacuumSystems During the 20th Century," Journal Vacuum Science and Technology, A, 2, 126-131 (1984).
8.P.A. Redhead, "The Measurement of Vacuum Pressures," Journal Vacuum Science and Technology, A, 2, 132-138 (1984).
9.J.F. Peterson, "Vacuum Pump Technology; A Short Course on Theory and Operations, Part I," Solid State Technology,24, 83-86 (1981).
10.R. Barbour, Glassblowing for Laboratory Technicians, Pergamon Press., Pergamon Press, Elmsford, NY, 1978, pp. 184-186.
References |
473 |
11.A.M. Russel, "Use of Water Aspirator in Conjunction with Sorption Pumping on an Ultrahigh Vacuum System," Review of Scientific Instruments, 36, 854 (1965).
12.P. Sadler, "Comparative Performance Characteristics Between a Vane and a Rotary Piston Type of Mechanical Vacuum Pump," Vacuum, 19, 17-22 (1969).
13.M.H. Hablanian, "Performance of Mechanical Vacuum Pumps in the Molecular Flow Range," Journal VacuumScience and Technology,A, 19, 250-252 (1981).
14.Welch Vacuum Technology, Inc., 1988, p. 125.
15.Z.C. Dobrowolski, "Mechanical Pumps," in Methods of Experimental Physics, Vol. 14, G.L. Weissler and R.W. Carlson , eds., Academic Press, New York, 1979, pp. 468-471.
16.N. Harris, Modern Vacuum Practice, McGraw-Hill, Berkshire England, 1989, pp. 78-80.
17.C.J. Carstens, C.A. Hord, and D.H. Martin, "Mercury Contamination Associated with McLeod Gauge Vacuum Pumps," Review of Scientific Instruments, 36, 1385-1386(1972).
18.M.H. Hablanian, "Comments on the History of Vacuum Pumps," Journal Vacuum Science and Technology,A, 2, 174-181 (1984).
19.J.F. O'Hanlon, A User's Guide to Vacuum Technology Wiley-Interscience, John Wiley & Sons, New York, 1980, p. 165.
20.M.H. Hablanian, "Mechanical Vacuum Pumps," Journal Vacuum Science and Technology, A, 19, 250-252 (1981).
21.W. Strattman, "Foreline Traps," Signs of the Times, 218, 34-38 (1996).
22.Shriver, DF, & Drezdzon, MA, The Manipulation of Air-Sensitive Compound,
Wiley-Interscience, John Wiley & Sons, New York, 1986, pp. 7-8.
23.Ibid.Ref. 22, p. 31.
24.R. Rondeau, "Design and Construction of Glass Vacuum Systems," Journal of Chemical Education, 42, A445-A459 (1965).
25.W. Strattman, Signs of the Times, February, 219, 48-64 (1997).
26.Ibid, Ref. 25.
27.M. Wheeler, "4" Glass Oil Diffusion Pump," Proceedings of the American Scientific Glassblowers Society Proceedings, 40th, 24-30 (1995).
28.N.S. Harris, "Practical Aspects of Constructing, Operating, and Maintaining Rotary Vane and Diffusion-Pumped Systems," Vacuum, 31, 173-182 (1981).
29.J.F. Peterson and H.A. Steinherz, "Vacuum Pump Technology; A Short Course on
Theory and Operations, Part I," Solid State Technology, 24, 83-86 (1981).
30.G.F. Weston, "Pumps for Ultra-high Vacuum," Vacuum, 28, 209-233 (1978).
31.Ibid, Ref. 30.
474 |
References |
32.L. Laurenson, "Vacuum Fluids," Vacuum,30, 275-281 (1980).
33.J.F. O'Hanlon, A User's Guide to Vacuum Technology Wiley-Interscience, John Wiley & Sons, New York, 1980, p. 198.
34.Ibid, Ref. 33.
35.D.J. Santeler, "Use of Diffusion Pumps for Obtaining Ultraclean Vacuum Environments," Journal of VacuumScience and Technology, 8, 299-307 (1971).
36.W.W. Roepke and K.G. Pung, "Inexpensive Oil Vapor Trap for Use with Rotary Vac-
uum Pumps," Vacuum, 18, 457-458 (1968).
37.Ibid, Ref. 21.
38.S. Dushman, J.M. Lafferty, Ed., Scientific Foundations of Vacuum Technique, John Wiley & Sons, New York, 1962, pp. 204-205.
39.F. Rosebury, Handbook of Electron Tube and Vacuum Techniques, American Institute of Physics, New York, 1993 (originally published in 1964), p. 212.
40.Brown, A.B., Proceedings of the American Scientific Glassblowers Society Proceedings, 30th, 80-82 (1985).
41.W Jitschin, "Accuracy of Vacuum Gauges," Journal Vacuum Science and Technology, A, 8, pp. 948-956 (1990).
42.International Vocabulary of Basic and General Terms in Metrology, ISO, Geneva, 1984.
43.P. Nash, "The Use of Hot Filament Ionization Gauges," Vacuum, 37, 643-649 (1987).
44.W. Jitschin, "Accuracy of Vacuum Gauges," Journal Vacuum Science and Technology, A, 8,948-956 (1990).
45.Ibid, Ref. 28, pp. 173-182.
46.S.T. Zenchelsky, "Pressure Measurement, Part One," Journal of Chemical Education, 40, A611-A632 (1963).
47.H.F. Carroll, "Avoid Parallax Error When Reading a Mercury Manometer," Journal of Chemical Education, 44, 763 (1967).
48.W.G. Brombacher, D.J. Johnson, and J.L. Cross, "Errors in Mercury Barometers and Manometers," Instruments & Control Systems, 35, 121-122 (1962).
49.S.O. Colgate and PA. Genre, "On Elimination of the Mercury Pumping Error Effect in McLeod Gauges," Vacuum, 18, 553-558 (1968).
50.J.K.N. Sharma et al., "A Simple Graphical Method of Pressure Determination in a McLeod Gauge," Vacuum, 31, 195-197 (1981).
51.K.B. Wear, "Condensable Gases in a McLeod Gauge," Review of Scientific Instruments, 39, 245-250 (1968).
52.C.J. Carstens, C.A. Hord, and D.H. Martin, "Mercury Contamination Associated with McLeod Gauge Vacuum Pumps," Review of Scientific Instruments, 43, 1385-1386(1972).
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475 |
53.W. Jitschin, "Accuracy ofVacuum Gauges," Journal Vacuum Science and Technology, A, 8, 948-956 (1990).
54.J.C. Snaith, "Vacuum Measurement," Journal of the British Society of Scientific Glassblowers, 7, 3-7 (1969).
55.R.N. Peacock, N.T. Peacock, and D.S. Hauschulz, "Comparison of Hot Cathode and Cold Cathode Ionization Gauges," Journal VacuumScience and Technology,A, 9, pp. 1977-1985 (1991).
56.W.B. Nottingham, 7th Ann. Conf. on Phys. Electron., M.I.T. (1947).
57.K.E. McCulloh and R. Tilford, "Nitrogen Sensitivities of a Sample of Commercial Hot Cathode Ionization Gas Tubes," Journal VacuumScience and Technology, A,
18,994-996(1981).
58.M. Hirata, M. Ono, H. Hojo, and K. Nakayama, "Calibration of Secondary Standard Ionization Gauges," Journal Vacuum Science and Technology,A, 20, 1159-1162 (1982).
59.H.C. Hseuh, "The Effect of Magnetic Fields on the Performance of Bayard-Alpert Gauges," Journal Vacuum Science and Technology,A, 20,237-240 (1982).
60.N.S. Harris, "Practical Aspects of Constructing, Operating, and Maintaining Rotary Vane and Diffusion-Pumped Systems," Vacuum, 31, 173-182 (1981).
61.Ibid, Ref. 60.
62.R.N. Peacock, N.T. Peacock, and D.S. Hauschulz, "Comparison of Hot Cathode and Cold Cathode Ionization Gauges," Journal VacuumScience and Technology,A, 9,
1977-1985 (1991).
63.N.S. Harris, "Practical Aspects of Constructing, Operating, and Maintaining Rotary Vane and Diffusion-Pumped Systems," Vacuum, 31, 173-182 (1981).
64.JJ. Sullivan, "Research Efforts Boost Range and Accuracy of Vacuum Gages,"
Industrial Res. & Dev., 25, 161-169 (1983).
65.H.A. Tasman et al., "Vacuum Techniques in Conjunction with Mass Spectrometry,"
Vacuum, 15, 33 (1963).
66.Ibid, Ref. 65.
67.D.F. Klemperer, "Recent Developments in Ultrahigh Vacuum," Journal of the British Society of Scientific Glassblowers, 2, 28-38 (1965).
68.Tom Orr, personal conversation.
69.A.H. Turnbull, "Leak Detection and Detectors," Vacuum, 15, 3-11 (1965).
70.Dr. Cathy Cobb, personal conversation.
71.D. Santeler, "Leak Detection—Common Problems and Their Solutions," Journal VacuumScience and Technology, A, 2, 1149-1156 (1984).
72.A.H. Turnbull, "Leak Detection and Detectors," Vacuum, 15, 3-11 (1965).
476 |
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73.W. Fiszdon, " 'Ad Hoc' Liquid Spray Vacuum Leak Detection Method," Physics of Fluids, 22, 1829-1831 (1979).
74.Ibid, Ref. 73.
75.G. Coyne and C. Cobb, "Efficient, Inexpensive, and Useful Techniques for Low Vacuum Leak Detection with a Tesla Coil," Journal of Chemical Education, 68, 526-528 (1991).
76.A. Guthrie, Vacuum Technology, John Wiley & Sons, New York, 1965, p. 514.
77.L.H. Martin and R.D. Hill, Manual of Vacuum Practice, Melbourne University Press, Melbourne, 1946, p. 112.
78.Ibid, Ref. 76, p. 514.
79.E.L. Wheeler, Scientific Glassblowing, Interscience Publishers, New York, 1958, p.
348.
80.W. Espe, Materials for High Vacuum Technology, Vol. 3, Pergamon Press, New York, 1968, p. 393.
81.J.F. O'Hanlon, A User's Guide to Vacuum Technology, John Wiley & Sons New York, 1980, p. 365.
82.Ibid, Ref. 71, pp. 1149-1156.
83.Ibid, Ref. 76, p. 468.
84.C.C. Minter, "Vacuum Leak Testing with Liquids," Rev. Sci. Inst., 31, 458-459 (1960).
85.Varian Associates, Inc. Introduction to Helium Mass Spectrometer Leak Detection, published by Varian Associates, Inc. ©1980.
86.N.G. Wilson, and L.C. Beavis, Handbook of Vacuum Leak Detection, published by the American Institute of Physics, Inc., © 1976, 1979, p. 26.
87.Ibid, Ref. 86, p. 37.
88.Ibid, Ref. 86 pp. 39.
89.Ibid, Ref. 71, pp. 1149-1156.