US2431757A - Psychrometer - Google Patents

Psychrometer Download PDF

Info

Publication number
US2431757A
US2431757A US577284A US57728445A US2431757A US 2431757 A US2431757 A US 2431757A US 577284 A US577284 A US 577284A US 57728445 A US57728445 A US 57728445A US 2431757 A US2431757 A US 2431757A
Authority
US
United States
Prior art keywords
tubes
thermometer
shields
tube
psychrometer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US577284A
Inventor
Kahl Joseph
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to US577284A priority Critical patent/US2431757A/en
Application granted granted Critical
Publication of US2431757A publication Critical patent/US2431757A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N25/00Investigating or analyzing materials by the use of thermal means
    • G01N25/56Investigating or analyzing materials by the use of thermal means by investigating moisture content
    • G01N25/62Investigating or analyzing materials by the use of thermal means by investigating moisture content by psychrometric means, e.g. wet-and-dry bulb thermometers

Definitions

  • My invention relates to improvements in psychrometers and it consists in the novel features which are hereinafter described.
  • One of the objects of my invention is to provide resilient clamps or holder positioned lengthwise the thermometer tubes, whereby to resist the tendency of the deflected air current at the lower end of the psychrometer to unduly bend the thermometer tubes and thereby to prevent their being broken; also to protect the tubes against shocks and strains produced by other causes.
  • Another object is to provide more than one such resilient clamp lengthwise each thermometer tube where the length of these tubes is considerable.
  • a further object of my invention is to provide a curved cross brace for connecting the side shields of the psychrometer to each other and to the central air tube and for securing the said resilient clamps thereto, whereby to protect the thermometer tubes against any strains due to possible lateral deflection of the side shields.
  • a still other object is to provide a means to protect the heat insulating couplings which join the curved cross brace to the radiation shields from excessive tension in their peripheries due to the exteriorly threaded ends of the spigots at the ends of the radiation shields extending too far into the interiorly threaded ends of the couplings.
  • Another object is to provide a means for keeping the inner radiation shields coaxial with the outer radiation shields, preferably by means of one or more spiders or multiple arms extending from one or both ends of each inner shield and to secure the said arms against deflection or breakage.
  • a further object is to have the said arms made in one with the metal at the ends of the inner shields and, to avoid temperature lag, the walls of the inner shields are made thinner at the part thereof which is intermediate between the ends which have thereon these spiders or multiple arms.
  • thermometer tube which would allow the turning of the tube about its axis when desired.
  • Fig. 1 is a fragmentary vertical section of my improved psychrometer on the line l-l of Fig. 2, showing only part of the fan housing and showing sundry parts in elevation.
  • Fig. 2 is a top plan view of the psychrometer omitting the fan housing.
  • Fig. 3 is a section on the line 3-3 of Fig. but showing the thermometer tube in plan view.
  • Fig. 4 is a central vertical section of one set of the radiation tubes and couplings, omitting the lower end of the enclosed thermometer tube.
  • Fig. 5 is a detail in section on the line 5-5 of Fig. 4 showing the spider on the upper end of the inner radiation shield and the reinforcing ring for the same.
  • Fig. 6 is a detail in section on the line 6-6 of Fig. 4, showing the spider on the lower end of the inner radiation shield and the heat insulatin sleeve thereon.
  • Fig. 7 is a detail in section on the line l! of Fig. 2.
  • I l designates a hollow base or fitting terminating at the upper end thereof in a hub l2 for connecting the same to one end of an air suction tube 13, the other end of which is shown as connected to a hub M which in turn is secured to the lower end l5 of a fan housing.
  • the fitting ll terminates at the lower end thereof in a U-shaped casing having thereon two socket l6 which receive therein each the exterriorly threaded end ll of a heat insulating coupling Hi, the lower end of which forms a housing 19 which terminates at the lower end thereof in an interiorly threaded socket 20 to receive therein the exteriorly threaded spigot end 2
  • keeps the latter from being forced too far into the socket 20, thereby avoiding excessve tensile stress in the periphery of the socket 20 of the coupling l8.
  • the tube l3 has secured thereto at the upper end thereof a cross-beam 2B which has mounted thereon the hub M by means of a flange 21 on the latter, which may be secured to the cross-beam 26 in any suitable manner.
  • the cross beam 26 also has connected thereto at each end thereof the upper end of each of a pair of side shields 2B, the lower ends of which are secured each to one side of the fitting ll.
  • cross beam 26 with the side shields 28 form the frame of the psychrometer.
  • the shields 28 are curved in cross-section as shown in Figs. 2 and 3 and serve to protect the thermometer tubes 24 from radiation by external objects located on the side of the psychrometer and also from collision with these and other objects.
  • thermometer tubes 24 may be connected to the cross beam 26 by being cemented in at their upper ends in sockets 29 of caps 30 which extend into openings 30a in the cross beam 26, and the caps 30 may be connected to the beam 26 as shown in Fig. 7 in detail:
  • Each cap 30 has at the upper end thereof a head 45 which extends above the beam 26 and has therein an opening for a pin 46 to be driven thereinto.
  • the pins 46 extend beyond the openings 30a in the cross beam 26 and serve to keep the caps 30 with the tubes 24 from being displaced downwardly.
  • Each cap 30 has therein an annular groove which receives therein one end of a threaded rod 43 which terminates at the other end in a knurled hand-wheel 44 which is shown in Fig. 2.
  • the cap 30 By turning the wheel 44 in one direction the cap 30 is secured to the cross-beam 26; and by turning the wheel 44 in the opposite direction the cap 30 is released and may be turned with the thermometer tube 24 in either direction, if desired.
  • the lower ends of the tubes 24 pass through openings in the fitting II which are somewhat larger than the tubes 24 without touching the walls of the fitting II at the peripheries of the said openings.
  • Air is circulated by a suction fan through the tube I3 and fitting ll past the lower ends of the tubes 24 and bulbs 3
  • the clamps 32-32a consist each of a pair of symmetrically placed plate springs 32 and 32a clasping a tube 24' therebetween; the upper ends of the springs are shown in Fig. 3 as concave at their upper ends on the sides thereof which are adjacent to the tube 24.
  • the braces 33 are shown in Fig. 3 as curved and fitting at their ends into the concave inner sides of the shields 28; at their middle portions the braces 33 have each a fork 34 connected thereto by soldering or otherwise, and are anchored thereby to the tube l3.
  • the springs 32 may be connected by means of screws or bolts passing through the braces 33 and shields 28, and the springs 32a may be likewise connected to the forks 34 and the tube l3.
  • thermometer tubes 24 being long, they are shown in the drawings with their middle portions broken away, as are also the shields 28 and the suction tube I3.
  • Two pairs of resilient clamps 32-32a for each tube 24 are shown as used with relatively long thermometers; one pair of clamps may be used with shorter thermometers.
  • the spider 35 and 36 are shown in detail in Fig. 5 and has connected thereto a metal ring 37 to keep the blades of the spider from being deflected from their positions.
  • the spider 36 is shown in detail in Fig. 6 and has thereon a sleeve 38 of heat-insulating material extending along part of the width of the blades, as shown in Fig. 4.
  • a heat insulating ring 39 is shown in Fig. 4 as placed between the ring 3'! and the spigot 2
  • the shield 23 is shown as having at its ends portions 40 and 4
  • the spiders 35 and 36 are slit from the portions 40 and 4
  • the portion 42 is made relatively thin to reduce the quantity of heat it could absorb and emit to transmit to the thermometer bulbs.
  • thermometer tubes supported each at the upper end thereof by the frame of the psychrometer, the lower ends of the thermometer tubes extending into the said base, said tubes passing through openings in the walls of said base which are larger than the tubes, and one or more resilient clamps connected to said frame in resilient contact with each of the thermometer tubes, whereby to protect the latter against lateral shocks.
  • a frame an air circulation system including a hollow base and an air suction tube, said frame including a pair of side shields, and one or more transverse braces connecting said shields to each other and to the suction tube, a pair of thermometer tubes supported each at the upper end thereof by said frame, the lower ends of the thermometer tubes extending into the said base and passing through openings in the walls of the base which are larger than the thermometer tubes, and one or more resilient clamps connected to said frame in resilient contact with each of the thermometer tubes, said clamps comprising each a pair of oppositely disposed springs connected to one of said shields and to said suction tube.
  • a frame having a horizontally disposed part, a pair of thermometer tubes, means for supporting the upper ends of the tubes, said means comprising caps pivotally connected to said horizontally disposed part of the frame and terminating each at the lower end thereof in a socket for receiving therein and holding the said ends, the caps having thereon each an annular groove, threaded rods in engagement with and passing through the part of the frame supporting said caps and removably extending into the said grooves, whereby normally to hold said caps with the tubes carried thereby against rotation and to allow rotation of the same when desired by removing the ends of the rods from the said grooves.
  • caps having their upper ends extending above the said horizontally disposed part and pins on said upper ends connected thereto transversely to said caps and adapted to be supported by said horizontally disposed part, thereby preventing the downward displacement of said caps with said tubes when said caps are released by said threaded rod.
  • thermometer tubes extending at their lower ends into the air circulation system, said system including a pair of coaxial heat radiation shields encompassing the lower end of each thermometer tube, the inner shield having thereon at the upper end thereof a set of outwardly extending arms for keeping it in alignment with the outer shield and a metal ring connected to the outer ends of said arms to maintain the same in a proper position with re lation to said shields.
  • thermometer tubes extending at their lower ends into the air circulation system, said system including a pair of coaxial heat radiation shields encompassing the lower end of each thermometer, the inner shield having thereon at each end thereof a set of outwardly extending arms of adequate thickness for keeping it in alignment with the outer shield, said arms being slitted from the metal of the inner shield at its ends, the walls of the shield at said ends being accordingly of adequate thickness also, and the thickness of the walls of said inner shield intermediate its end being reduced, thereby reduoing its heat absorbing and emitting capacity.
  • thermometer tubes extending at their lower ends into the air-circulation system, said system including an inverted U- shaped casing, a pair of heat insulating couplings at the lower ends of the branches of said casing, outer and inner heat radiation shields encompassing the lower ends of the thermometer tubes, connected to said couplings, said couplings having thereon at the lower ends thereof interiorly threaded sockets, said outer shields having at their upper ends exteriorly threaded spigots in engagement with said sockets, and shoulders on said outer shields at said spigots to limit the extension of said spigots into the said sockets, whereby to limit the tensile stress in the peripheries of said couplings produced by an excessive extension of said spigots thereinto.

Description

7 3 8 6 v oudi'cn $100313 Dec. 2, 1947. J, KAHL 2,431,757
PSYCHBOMETER Filed Feb. 10, 1945 ATTORNEY Patented Dec. 2, 1947 Search Room UNITED STATES PATENT OFFICE PSYCHROMETER Joseph Kahl, New York, N. Y.
Application February 10, 1945, Serial No. 577,284
9 Claims. 1
My invention relates to improvements in psychrometers and it consists in the novel features which are hereinafter described.
One of the objects of my invention is to provide resilient clamps or holder positioned lengthwise the thermometer tubes, whereby to resist the tendency of the deflected air current at the lower end of the psychrometer to unduly bend the thermometer tubes and thereby to prevent their being broken; also to protect the tubes against shocks and strains produced by other causes.
Another object is to provide more than one such resilient clamp lengthwise each thermometer tube where the length of these tubes is considerable.
A further object of my invention is to provide a curved cross brace for connecting the side shields of the psychrometer to each other and to the central air tube and for securing the said resilient clamps thereto, whereby to protect the thermometer tubes against any strains due to possible lateral deflection of the side shields.
A still other object is to provide a means to protect the heat insulating couplings which join the curved cross brace to the radiation shields from excessive tension in their peripheries due to the exteriorly threaded ends of the spigots at the ends of the radiation shields extending too far into the interiorly threaded ends of the couplings.
Another object is to provide a means for keeping the inner radiation shields coaxial with the outer radiation shields, preferably by means of one or more spiders or multiple arms extending from one or both ends of each inner shield and to secure the said arms against deflection or breakage.
A further object is to have the said arms made in one with the metal at the ends of the inner shields and, to avoid temperature lag, the walls of the inner shields are made thinner at the part thereof which is intermediate between the ends which have thereon these spiders or multiple arms.
A still other object is to provide a support for the upper end of each thermometer tube which would allow the turning of the tube about its axis when desired.
Other objects and advantages will hereinafter appear.
I attain these objects by the psychrometer which is shown in the accompanying drawings or by any mechanical equivalent or obvious modification of the same.
In the drawings:
Fig. 1 is a fragmentary vertical section of my improved psychrometer on the line l-l of Fig. 2, showing only part of the fan housing and showing sundry parts in elevation.
Fig. 2 is a top plan view of the psychrometer omitting the fan housing.
Fig. 3 is a section on the line 3-3 of Fig. but showing the thermometer tube in plan view.
Fig. 4 is a central vertical section of one set of the radiation tubes and couplings, omitting the lower end of the enclosed thermometer tube.
Fig. 5 is a detail in section on the line 5-5 of Fig. 4 showing the spider on the upper end of the inner radiation shield and the reinforcing ring for the same.
Fig. 6 is a detail in section on the line 6-6 of Fig. 4, showing the spider on the lower end of the inner radiation shield and the heat insulatin sleeve thereon.
Fig. 7 is a detail in section on the line l! of Fig. 2.
Similar numerals refer to throughout the several views.
I l designates a hollow base or fitting terminating at the upper end thereof in a hub l2 for connecting the same to one end of an air suction tube 13, the other end of which is shown as connected to a hub M which in turn is secured to the lower end l5 of a fan housing.
The fitting ll terminates at the lower end thereof in a U-shaped casing having thereon two socket l6 which receive therein each the exterriorly threaded end ll of a heat insulating coupling Hi, the lower end of which forms a housing 19 which terminates at the lower end thereof in an interiorly threaded socket 20 to receive therein the exteriorly threaded spigot end 2| of an outer radiation shield 22, which with a corresponding inner radiation shield 23 is for encompassing the lower end of each thermometer tube 24. A shoulder 25 on the shield 22 at said spigot 2| keeps the latter from being forced too far into the socket 20, thereby avoiding excessve tensile stress in the periphery of the socket 20 of the coupling l8.
The tube l3 has secured thereto at the upper end thereof a cross-beam 2B which has mounted thereon the hub M by means of a flange 21 on the latter, which may be secured to the cross-beam 26 in any suitable manner.
The cross beam 26 also has connected thereto at each end thereof the upper end of each of a pair of side shields 2B, the lower ends of which are secured each to one side of the fitting ll.
similar parts The cross beam 26 with the side shields 28 form the frame of the psychrometer.
The shields 28 are curved in cross-section as shown in Figs. 2 and 3 and serve to protect the thermometer tubes 24 from radiation by external objects located on the side of the psychrometer and also from collision with these and other objects.
The thermometer tubes 24 may be connected to the cross beam 26 by being cemented in at their upper ends in sockets 29 of caps 30 which extend into openings 30a in the cross beam 26, and the caps 30 may be connected to the beam 26 as shown in Fig. 7 in detail:
Each cap 30 has at the upper end thereof a head 45 which extends above the beam 26 and has therein an opening for a pin 46 to be driven thereinto.
The pins 46 extend beyond the openings 30a in the cross beam 26 and serve to keep the caps 30 with the tubes 24 from being displaced downwardly.
Each cap 30 has therein an annular groove which receives therein one end of a threaded rod 43 which terminates at the other end in a knurled hand-wheel 44 which is shown in Fig. 2.
By turning the wheel 44 in one direction the cap 30 is secured to the cross-beam 26; and by turning the wheel 44 in the opposite direction the cap 30 is released and may be turned with the thermometer tube 24 in either direction, if desired.
The lower ends of the tubes 24 pass through openings in the fitting II which are somewhat larger than the tubes 24 without touching the walls of the fitting II at the peripheries of the said openings.
Air is circulated by a suction fan through the tube I3 and fitting ll past the lower ends of the tubes 24 and bulbs 3| thereon.
To protect the tubes 24 against lateral strains due to the action of the current of air as it is being deflected from the sockets IS in the fitting H into the tube I3 I provide resilient clamps 32--32a, transverse braces 33 and forks 34 which are connected to the side shields 28 and tube 13 by suitable fastenings which are not shown in the drawings.
The clamps 32-32a consist each of a pair of symmetrically placed plate springs 32 and 32a clasping a tube 24' therebetween; the upper ends of the springs are shown in Fig. 3 as concave at their upper ends on the sides thereof which are adjacent to the tube 24.
The braces 33 are shown in Fig. 3 as curved and fitting at their ends into the concave inner sides of the shields 28; at their middle portions the braces 33 have each a fork 34 connected thereto by soldering or otherwise, and are anchored thereby to the tube l3.
The springs 32 may be connected by means of screws or bolts passing through the braces 33 and shields 28, and the springs 32a may be likewise connected to the forks 34 and the tube l3.
The thermometer tubes 24 being long, they are shown in the drawings with their middle portions broken away, as are also the shields 28 and the suction tube I3.
Two pairs of resilient clamps 32-32a for each tube 24 are shown as used with relatively long thermometers; one pair of clamps may be used with shorter thermometers.
To keep the outer radiation shield 22 and the inner radiation shield 23 coaxial with each other I provide the spiders 35 and 36 on the two ends of the shield 23; the spider 35 is shown in detail in Fig. 5 and has connected thereto a metal ring 37 to keep the blades of the spider from being deflected from their positions.
The spider 36 is shown in detail in Fig. 6 and has thereon a sleeve 38 of heat-insulating material extending along part of the width of the blades, as shown in Fig. 4.
A heat insulating ring 39 is shown in Fig. 4 as placed between the ring 3'!" and the spigot 2| of the shield 22.
The shield 23 is shown as having at its ends portions 40 and 4| thicker than the intermediate portion 42. The spiders 35 and 36 are slit from the portions 40 and 4| respectively.
The portion 42 is made relatively thin to reduce the quantity of heat it could absorb and emit to transmit to the thermometer bulbs.
Variations are possible and parts of my invention may be used without other parts.
I do not, therefore, restrict myself to the details as shown in the drawings.
I claim as my invention and desire to secure by Letters Patent:
1. In a psychrometer, a frame, an air circulation system including a hollow base, a pair of thermometer tubes supported each at the upper end thereof by the frame of the psychrometer, the lower ends of the thermometer tubes extending into the said base, said tubes passing through openings in the walls of said base which are larger than the tubes, and one or more resilient clamps connected to said frame in resilient contact with each of the thermometer tubes, whereby to protect the latter against lateral shocks.
2. In a psychrometer, a frame, an air circulation system including a hollow base and an air suction tube, said frame including a pair of side shields, and one or more transverse braces connecting said shields to each other and to the suction tube, a pair of thermometer tubes supported each at the upper end thereof by said frame, the lower ends of the thermometer tubes extending into the said base and passing through openings in the walls of the base which are larger than the thermometer tubes, and one or more resilient clamps connected to said frame in resilient contact with each of the thermometer tubes, said clamps comprising each a pair of oppositely disposed springs connected to one of said shields and to said suction tube.
3. In a psychrometer, a frame having a horizontally disposed part, a pair of thermometer tubes, means for supporting the upper ends of the tubes, said means comprising caps pivotally connected to said horizontally disposed part of the frame and terminating each at the lower end thereof in a socket for receiving therein and holding the said ends, the caps having thereon each an annular groove, threaded rods in engagement with and passing through the part of the frame supporting said caps and removably extending into the said grooves, whereby normally to hold said caps with the tubes carried thereby against rotation and to allow rotation of the same when desired by removing the ends of the rods from the said grooves.
4. The elements of claim 3, said caps having their upper ends extending above the said horizontally disposed part and pins on said upper ends connected thereto transversely to said caps and adapted to be supported by said horizontally disposed part, thereby preventing the downward displacement of said caps with said tubes when said caps are released by said threaded rod.
Search Room 5. In a psychrometer, an air circulation system, a pair of spaced thermometer tubes extending at their lower ends into the air circulation system, said system including a pair of coaxial heat radiation shields encompassing the lower end of each thermometer tube, the inner shield having thereon at the upper end thereof a set of outwardly extending arms for keeping it in alignment with the outer shield and a metal ring connected to the outer ends of said arms to maintain the same in a proper position with re lation to said shields.
6. In a psychrometer, an air circulation system, a pair of spaced thermometer tubes extending at their lower ends into the air circulation system, said system including a pair of coaxial heat radiation shields encompassing the lower end of each thermometer, the inner shield having thereon at each end thereof a set of outwardly extending arms of adequate thickness for keeping it in alignment with the outer shield, said arms being slitted from the metal of the inner shield at its ends, the walls of the shield at said ends being accordingly of adequate thickness also, and the thickness of the walls of said inner shield intermediate its end being reduced, thereby reduoing its heat absorbing and emitting capacity.
7. The elements of claim 5, combined with a ring of heat insulating material interposed between said metal ring and the upper end of said outer shield adjoining the same in the said air circulation system.
8. The elements of claim 6, combined with a means for heat insulating each of said sets of arms from the said outer shield.
9. In a psychrometer, an air circulation system, a pair of spaced thermometer tubes extending at their lower ends into the air-circulation system, said system including an inverted U- shaped casing, a pair of heat insulating couplings at the lower ends of the branches of said casing, outer and inner heat radiation shields encompassing the lower ends of the thermometer tubes, connected to said couplings, said couplings having thereon at the lower ends thereof interiorly threaded sockets, said outer shields having at their upper ends exteriorly threaded spigots in engagement with said sockets, and shoulders on said outer shields at said spigots to limit the extension of said spigots into the said sockets, whereby to limit the tensile stress in the peripheries of said couplings produced by an excessive extension of said spigots thereinto.
JOSEPH KAI-IL.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date 1,791,020 Wilson Feb. 3, 1931 2,159,133 Chappell et al May 23, 1939 2,264,966 Burdick et al Dec. 2, 1941 FOREIGN PATENTS Number Country Date 691,588 Germany May 31, 1940 967 Great Britain Jan. 14, 1904
US577284A 1945-02-10 1945-02-10 Psychrometer Expired - Lifetime US2431757A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US577284A US2431757A (en) 1945-02-10 1945-02-10 Psychrometer

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US577284A US2431757A (en) 1945-02-10 1945-02-10 Psychrometer

Publications (1)

Publication Number Publication Date
US2431757A true US2431757A (en) 1947-12-02

Family

ID=24308053

Family Applications (1)

Application Number Title Priority Date Filing Date
US577284A Expired - Lifetime US2431757A (en) 1945-02-10 1945-02-10 Psychrometer

Country Status (1)

Country Link
US (1) US2431757A (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB190400967A (en) * 1904-01-14 1904-11-17 Albert John Murphy Improvements in or relating to Apparatus for Indicating the Temperature of Kilns or other Hot-air Chambers used in Drying Grain and like Materials.
US1791020A (en) * 1931-02-03 Apparatus for measuring the temperature of gases
US2159133A (en) * 1936-06-26 1939-05-23 Bendix Aviat Corp Hand aspirating psychrometer
DE691588C (en) * 1936-10-23 1940-05-31 Siebert & Kuehn G M B H Dr Double thermometer for psychrometer
US2264966A (en) * 1938-09-29 1941-12-02 Burdick Charles Laurence Determination of the moisture content of substances

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1791020A (en) * 1931-02-03 Apparatus for measuring the temperature of gases
GB190400967A (en) * 1904-01-14 1904-11-17 Albert John Murphy Improvements in or relating to Apparatus for Indicating the Temperature of Kilns or other Hot-air Chambers used in Drying Grain and like Materials.
US2159133A (en) * 1936-06-26 1939-05-23 Bendix Aviat Corp Hand aspirating psychrometer
DE691588C (en) * 1936-10-23 1940-05-31 Siebert & Kuehn G M B H Dr Double thermometer for psychrometer
US2264966A (en) * 1938-09-29 1941-12-02 Burdick Charles Laurence Determination of the moisture content of substances

Similar Documents

Publication Publication Date Title
US2431757A (en) Psychrometer
US2232816A (en) Electric lamp
US2451900A (en) Electrical discharge device and base
US2659023A (en) Filament structure
US2030820A (en) Electric heater
US3946221A (en) Orientable lighting fixture
US1975140A (en) Vacuum tube stem
US2298965A (en) Electrical discharge device
US2425864A (en) Filament supporting structure for incandescent lamps
US2410993A (en) Support for filament assemblies
US2565138A (en) Filament support structure for incandescent lamps
US2458218A (en) Filament assembly structure
US2478969A (en) Electron tube mount stabilizer support
US2338621A (en) Electric lamp
US3134042A (en) Cap-shaped cathode for cathode ray tubes
US2399757A (en) Tube
US3522467A (en) Electron tube filament support structure employing deformable loop portions of the filaments
US2422819A (en) External anode electron tube
US1651287A (en) Electric incandescent lamp made of glass tubing
US2693544A (en) Resnatron filament basket
US2372208A (en) Gaseous discharge tube
US1653385A (en) Lamp mount
US1116595A (en) Incandescent lamp.
US1508302A (en) Incandescent lamp
US2468433A (en) Multiunit electron tube