Thermometer has a white back, 6-7mm outer diameter and a standard taper 7/12 inner ground joint. 5 and 6, the lower end of the capillary bore is just slightly below the triangular section and actually is slightly into the circular cross-section of the downwardly tapering conical tip 45. in the order of 1/2 to 11/2 seconds. Pressurized gas was introduced into the bore resulting in expansion of the closed end of the bore and the corresponding portion of the side walls of the blank. In areas, where the upper temperature limit is 38.83C, one may employ a mercury-thallium alloy thermometer having a freezing i.e. npt thermometer bimetal

The thermometer blank, as has been pointed out previously, is of triangular configuration in cross-section. It thus will be seen that there are provided a device which achieves the various objects of the invention and which is well adapted to meet the conditions of practical use. 3 and 4, it is basically of triangular shape with rounded corners at the back of the thermometer which is the portion wherein the strip is embedded and it also has a rounded corner at the front of the thermometer.

The liquid in glass thermometer, is the most commonly used device to measure temperature and it is inexpensive to make and easy to use.

thermometers pfa wikia Thereafter, the thermometer is cooled slowly to room temperature, for example, at a rate of 50 F. per hour. This causes the still-hot lower downwardly tapered conical end of the blank to expand so as to form a bulb having a hollow interior and an external surface which engages the walls of the die cavity. as grooves, threads or mouths, Reshaping the ends, e.g. Besides, they can not provide digital and automated results. After the tip 45 has been so formed, the blank 10 is moved i.e., indexed, to another position relative to the stationary disc 36. 1 shows a perspective view of an apparatus for holding a clinical glass thermometer blank in a vertical position; FIG. No. An intermediate portion 20 of the blank is held by a vise 22 the construction of which is an ancillary feature of the present invention. -30C to 50C. Attention is called to the fact that the diameter of the circular cavity 51 is somewhat larger than the imaginary circumscribing cylinder for the therometer blank. In a preferred embodiment of the invention, the diameter of the cavity is approximately 15% greater than the diameter of the aforesaid imaginary circumscribing cylinder. It will be appreciated that the blank can be inserted into the vise first while the upper end of the blank is below the chuck, and that after the blank has been placed in the vise it can be moved longitudinally upwardly to engage the chuck. 4 is an enlarged view of the thermometer blank and spring-loaded pins shown in FIG. Typically, the stress as relieved is less than 200 lbs. Still further, this method did not provide a desired smooth shape for the extreme tip of the bulb. These particles tended to enter the capillary bore during loading of the thermometer and also use of the thermometer, thereby creating thermometers known as "hard shakers", these being thermometers in which the mercury column would not readily recede after using the same to measure a temperature even when they were whipped quite rapidly. By means of a maximum thermometer, one can measure the maximum temperature over a predetermined time span. 6. How to Size a Cable for Industrial AC Motors? The upper end 16 of the blank 10 is vertically held within a conventional chuck 18 with which there is associated a standard release and tightening mechanism 19, the details of which are unimportant to the present invention. You can unsubscribe at any time. Alternatively, the bulb was rotated with non-cylindrical dies to provide bulbs of different shapes. Unlike electrical thermometers, they do not necessitate power supply or batteries for charging. Subsequently, the thermometer with the formed bulb thereon is charged with mercury, has thermometer graduations placed on the stem, has the quantity of mercury adjusted to conform to the thermometer, is evaculated and closed, the sequence of steps subsequent to the formation of the bulb varying with the manufacture and depending upon the particular methods employed for charging, forming the markings, closing and evacuating the upper end of the thermometer and adjusting the quantity of mercury therein. A very thin opening, called a bore, exists from the bulb and extends down the centre of the tube. In the clinical glass thermometer field, thermometer bulbs are of three general types. The burners are so distributed and a sufficient number thereof is provided so that the portion of the blank being heated has its temperature substantially uniformly raised to a temperature above the flow point of the glass, for example, between approximately 1200 F. -1500 F. Due to the force of gravity on the part of the glass blank below the heated zone, the heated zone begins to stretch and forms an elongated section 42. 1, a thermometer blank 10 is illustrated having a capillary bore 12 extending lengthwise thereof and formed therein prior to use of the blank in the method of the present invention. 4 where they rest agsinst the back surface of the thermometer blank to hold the blank in the vise 22 while the upper end of the blank is being held in the chuck 18. Terms & Conditions, Thomas Traceable Dew Point/Wet Bulb/Humidity/Thermometer, "Accutherm" Bulb Immersion Thermometers - Spirit, Bluetooth Thermometer Hygrometer Data Loggers, Heat Stress WBGT (Wet Bulb Globe Temperature) Meter, Pocket Test Thermometers, Aluminum Case, Red Spirit Filled, H-B DURAC, Liquid-In-Glass Wall Thermometer; Organic Liquid Fill, SYNTHWARE Short Path Vacuum Jacketed Distillation Apparatus, Pocket Test Thermometers, Clear Plastic Case, Red Spirit Filled. A temperature scale which is basically preset or imprinted on the stem for displaying temperature readings. We Believe You Are Important, How Can We Help? Built-in illumination aids viewing of the melting point. After annealing, the thermometer is completed, using standard techniques for charging mercury into the thermometer blank, adjusting the quantity of mercury in the blank, providing graduations on the blank and closing the upper end of the blank. They are followed by the usual steps that are employed to complete the fabrication of a clinical thermometer. Related Products: Mercury Filled Thermometer, Red Spirit Filled In Enclosed and Armor Aluminum Cases Aluminum Cases have Pocket Clips Length 6" (155mm) Permanent Markings Toughened Bulbs Total Immersion Thermometers Replacable, Related Products: Total Immersion Thermometer, Use this simple apparatus to measure relative humidity. to eliminate workplace and environmental hazards associated with mercury. Mercury does not cling to glass, and it expands and contracts at a predictable rate. Following are the major advantages associated with the use of liquid-in-glass thermometers: Use of liquid-in-glass thermometers includes following limitations too: There are two major types ofLiquid-in-glass thermometerswhich are mentioned below: This type of thermometer was developed by a German based physicist namedDaniel Gabriel Fahrenheit. All ranges have a 2 subdivisions. The viewing cover can be removed to easily clean and change the bulb. This pocket ultimately will become the interior of the bulb of the finished thermometer. Amaximum thermometeris a unique kind of mercury thermometer which functions by having a constriction in the neck close to the bulb. The chuck 18 clamps or grips the upper end 16 of the thermometer blank 10 with a force that is sufficient to prevent the blank 10 from falling downwardly. Next, the blank 10, now having the downwardly tapered conical tip 45 which is uniformly heated to above the flow point of the glass, is indexed to a further position with respect to the stationary support. An industrial thermometer is shown in Below Figure (Right). An inert gas, mainly argon or nitrogen which is filled inside the thermometer above mercury to trim down its volatilization. The close coupled condenser and vacuum connection offer and extremely short condensate travel path. Omega Engineering: Introduction to Glass Thermometers, Purdue University: Mercury Thermometers FAQ. per square inch. It is sufficient to observe that the mechanism 19 in one position will tighten the chuck on the upper end of the blank and in another position will release the chuck. The thermometers mount on a wooden handle so they can be spun to obtain tem, Kit is a simple hygrometer used in measuring the moisture content in the air. Moreover, this is accomplished without forming any external protuberances on the bulb that might irritate tender mucous membranes. Preferably, an inert gas such as nitrogen is used. Related Products: Distillation Thermometer, Red Spirit_Filled In Clear Plastic Pocket Case Cases have Pocket Clips Length 6" (155mm) Permanent Markings Toughened Bulbs Total Immersion, up to 6 environmental parameters Built-in multiparameter sensor measures Heat Index, Wet Bulb Globe Temperature (WGBT), Humidity, Ambient Temperature, Temperature, Dew Point and Wet Bulb User Programmable Heat Index/WBGT alarm MIn/Max/Average Data Hold, Auto Power Off with disable, Cards ROHS Compliant CE Mark 1-year warranty Reads relative humidity (RH) and ambient temperature dew point and wet bulb, and functions as a type K or J thermometer. Dual scales of -10/50C and , All complete units supplied with a buret, a CG-3502-04, -10 to 260 thermometer, a CG-1042-01 24/40 thermometer adapter and a leveling bulb with a 24/40 top outer and a lower detachable hose connection. The principle used to measure temperature is that of the apparent thermal expansion of the liquid. Korpella's work has appeared in a variety of publications. A thermometer as set forth in claim 1 wherein the diameter of the bulb is from 20% more to 20% less of the diameter of an imaginary cylinder circumscribing the stem..Iaddend. 9 is a view similar to FIG. Accordingly, two such sets of gas jets 50 will be seen in FIG. As this happens, the chuck is released and the thermometer blank may be pulled out by hand from the vise 22. As temperatures decrease, the mercury has some place to go as it recedes back into the bulb. After the thermometer bulb strikes the paper, catch the thermometer with your other hand to prevent breakage. Next, the still-hot lower end, either with or without further application of heat to keep the same at a suitable temperature for deformation, is introduced into an open-topped cavity of a one-piece mold, i.e., a non-split mold. It equally well could have been the configuration of an oral type thermometer. A swelling, or bulb, at the bottom of the thermometer stores the mercury used in calculating temperature readings. They provide very good repeatability and their calibration remains unaffected. However, the apex of the conical tip is spaced from the bottom wall of the die cavity by an amount suitable to locate the finished bulb properly, i.e., in its desired position with respect to the triangular part of the thermometer blank. If the bulb diameter were greater than the indicated percentage, the wall of the bulb would be too thin and too likely to break, it would be of a thickness which was thinner than the bottom of the bulb, which is undesirable, and it would not fit into openings of commercial centrifuges which are employed for re-setting the mercury column. Slide-rule humidity calculator is silk-screened on case. Preferably, however, the present invention constitutes a thermometer with a cylindrical bulb inasmuch as, as has been mentioned previously, the unique configuration of the lower end of the bulb after the closing of the capillary bore lends itself peculiarly well to the formation of uniform side wall and bottom wall thicknesses in a cylindrical bulb. It is heated approximately 1/2 inches from the lower end 38 thereof (see FIG. Slide rule range is, humidity readings anywhere by comparing the reading of the wet and dry bulb thermometers on the enclosed humidity chart. 1. 3,285,727. However, it doesnt result in expansion upon solidification and hence there will be no danger of glass breakage of the thermometer tube. A monocoque glass clinical thermometer in which the bulb and stem are formed from the same piece of glass and in which the exterior of the bulb is of circular, preferably cylindrical, section and is completely free of protuberances that give rise to irritation in normal use of the thermometer. The force of gravity has caused this lower end to assume a downwardly tapering conical configuration which best is illustrated in FIG. As the pocket is formed, the glass of the tip is forced downwardly and at the same time expanded radially outwardly. The Effect of Wavelength on Photovoltaic Cells, Ways to Predict a Storm With Air Pressure. A working liquid which is generally either mercury or alcohol. as grooves, threads or mouths by blowing, Thermometers specially adapted for specific purposes, Clinical contact thermometers for use with humans or animals, Measuring temperature based on the expansion or contraction of a material the material being a liquid with provision for expansion indicating over not more than a few degrees, GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS, TECHNICAL SUBJECTS COVERED BY FORMER USPC, TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS, Method of making a clinical monocoque glass thermometer, Thermometer and method for its manufacture, Thermometer bubble pressing and blowing machine, Overflow machine is again used in mercury clinical thermometer production, Method of and apparatus for making tubing, Glass syringe barrel forming method and machine, Method and device for the production of foreign body-free glass vessels, in particular ampoules, injection bottles and the like. 2. The thin bore is called a capillary. Free Instrumentation Course for Trainee Engineers, Single Push button to ON and OFF a Bulb using Ladder Logic. What is Thermowell and How-to choose Thermowell Probe Length ? 7 shows the tapered and still-hot lower portion o the thermometer blank inserted into a one-piece non-split die cavity while gas under pressure is introduced through the top end of the thermometer blank so as to inflate the sealed lower end into the shape of the cavity; FIG. In addition, our thermometers have a number of extra quality features built in: Red Liquid Expansion Chambers Reinforced Bulbs to prevent breakage Horizontally. The stem was made from standard Corning lead thermometer glass and the bulb was made from a different type of material which was dimensionally stable upon stress relief at room temperature. In the prior art it has been conventional to form clinical glass thermometers by fusing to the bottom of the stem a previously formed bulb of thin section in suitable configuration. Robert Korpella has been writing professionally since 2000. The freezing point of mercury is 38.83C at which it gets solidified. A clinical glass thermometer in accordance with claim 1 wherein said bulb has a diameter equal to or not greater than 20% of the diameter of an imaginary cylinder circumscribing said stem..]..Iadd.

Clinical thermometers so made had a high reject rate which was caused from internal undercuts that arose from misalignment of the walls of the stem and the bulb. Some thermometers are called partial immersion types, and these include a line engraved across the stem that marks the depth at which the thermometer should be immersed in a substance in order to get a good temperature reading. When the pressurized gas is introduced into the upper end of the thermometer blank as aforesaid, the lower end of the capillary bore will cause a pocket to be formed within the hot conical downwardly tapering tip of the thermometer blank. Instructions, High-impact, plastic case serves as a pivoted handle in use Wet and dry bulb thermometers, range 20 to 120F in 1 divisions Swivel-mount assures that the whirling thermometers always face air flow. Due to this particular method of applying heat and allowing the scrap to drop away, the lower end of the thermometer blank is formed into a downwardly tapered conical shape and, at the same time, the heat causes the capillary bore normally present in a clinical thermometer blank to close, sealing the lower end of the bore. The blank is held in upright position with a special type of jig, although this is not necessary to the practice of the invention.

The second type has a pear-shaped bulb and is known as the rectal type. 5) by gas burners 40 which burners are mounted on the stationary support disc 36. When spun around on their wooden handle, the wet bulb thermometer and the dry bulb thermometer will read different temperatures. While the present invention hereinafter will be described with reference to a stubby type thermometer of the monocoque variety, it is to be understood that this method can be applied equally as well to form clinical thermometers having long cylindrically shaped bulbs or a pear-shaped bulb. Stopcock bore, One thermometer bulb is kept constantly wet by a siphon reservoir while the other gives a dry temperature reading. Moreover, due to the uniform thickness, the side wall is thicker than it would be in a conventional thermometer and, therefore, stronger while at the same time the bottom wall is thinner than it would be in a conventional thermometer and yet still is thick enough, being approximately equal to the thickness of the side wall, to resist breakage to the same degree as the side wall. The contraction chamber affords the person taking a temperature reading a little time to get an accurate reading after removing the thermometer from a heated source. The mercury is forced up through the constriction by the force of expansion as the temperature increases. It will be observed that if the die cavity did not confine the bulb as it was being expanded, it would form a ball, and the thickness of the wall would not be uniform as it is with the confining restraint exercised by the aforesaid die cavity. A bulb which acts as a container for the functioning liquid where it can easily expand or contract in capacity. It does not tend to blow out too markedly because this transformation zone is not as hot and therefore does not flow as readily as the more highly heated downwardly tapering conical tip. Magnified glass makes up the outside jacket of the thermometer, which is called the stem. In addition, the apparatus to form the aforesaid steps was relatively expensive and the process for operating the apparatus was expensive and required the use of skilled help, thus increasing the price of the thermometer. 9. Thus, the thermometer blank with the bulb thereon is placed in a heating chamber C (see FIG. The range is affected by the metal with which mercury is amalgamated. Thermometer is mounted to a molded plastic case that protects the bulb. 21, 1974, now U.S. Pat. The die cavity 51 has a configuration which matches the desired ultimate configuration of a bulb 54 eventually to be formed at the lower end of the thermometer, blank 10, except for the transformation section between the unblown part of the thermometer blank (the part immediately above the bulb and the bulb itself). Due to the special shape above described of the heated lower end of the blank, the bulb thus formed has a high degree of uniformity of wall thickness, that is to say, the thickness of the side wall of the bulb is approximately equal to the thickness of the rounded bottom wall of the bulb. No. After the completion of the bulb-forming step, the thermometer blank is raised to lift the bulb out of the die cavity and the blank is indexed to another station in which the mechanism 19 engages a stationary post 60 attached to the disc 36. The gas which is introduced into the open upper end of the capillary bore is under a mild pressure such as is commonly employed for blowing a glass bulb from a capillary bore in a clinical thermometer. As various possible embodiments might be made of the above invention, and as various changes might be made in the embodiment above set forth, it is to be understood that all matter herein described or shown in the accompanying drawings is not to be interrupted as illustrative and not in a limiting sense. They can not be applied in regions where highly accurate results are desirable. One can also mount the thermometer vertically for overnight which will let the drawing back of alcohol to the column. 11) and there heated and annealed and slowly cooled to leave a negligible residual stress which in the thermometer art is considered to be essentially absent. It takes place in approximately 2 to 3 seconds. FIG.

They can be frequently applied in areas where there is problem of electricity. Gases compress inside the expansion chamber until the mercury flows back down the capillary and into the bulb as temperatures fall. Some thermometers also have a tight restriction just above the contraction chamber. Hold the thermometer in a vertical position, bulb end down, 4 to 6 inches over the wood surface covered with paper, and then drop. This has certain desirable effects; one is esthetic. The bottom of the cavity is provided with a vent passageway 56 which opens to the atmosphere. The bottom wall no longer is unusually thick to create a bull's-eye lens effect which was common in previously manufactured thermometers. The bulb is typically made of glass, but some thermometers may have bulbs made of stainless steel instead. 6) which eventually separates from the portion of the stem above it. The column 35 passes through a stationary disc 36 that is located below the rotatable disc 30. Related Products: Non Mercury Thermometer. No. 3 is a top view of the vise and thermometer blank shown in FIG. In the Liquid In Glass Thermometers (LIG) the thermally sensitive element is a liquid contained in a graduated glass envelope. 1; FIG. This end is subjected to heating with a flame that concentrates its heat to a point above the lower tip of the blank. It aids in increasing the sensitivity of the thermometer. 1, by tubes 32 and brackets 34, respectively. Includes two plastic-backed Celsius thermometers, one for dry bulb measurements and the other for wet bulb measurements.

Preferably, this is accomplished with a bulb that is of cylindrical configuration so far as its side wall is concerned, being either a short cylinder or a long cylinder, depending upon the ultimate desired configuration of the thermometer bulb. 3. In the accompanying drawings in which is shown one of the various possible embodiments of the invention: FIG. Environmental concerns about mercury are prompting manufacturers to look for substitute materials, but many mercury thermometers are still in use. Referring now in detail to the apparatus shown in FIG.

In this method, however, the rotation of the stem and of the rotary dies cuased the opaque strip against which the mercury column was to be read to be severely twisted resulting in an unsightly spiral within the bulb. Ultimately, the strand breaks and the strand, including the portion of the former blank beneath it, drops to waste. In either event, the cavity 51 is of a uniform circular cross-section, except for the bottom which is rounded and concave to impart a convex-configuration to the lower end of the bulb. To overcome the difficulty with thermometers formed from separate stem blanks and bulbs of different materials, it has been proposed to form thermometers as shown in McGill U.S. Pat. High temperature portion of the thermometer can be warmed up beneath an incandescent lamp which will bring the alcohol down to the column. Mounted in fenestrated plastic armor with perforated bulb guard and suspension ring Range of -5 to +45C in 0.5 increments, black on yellow scale, downloadable as a CSV file Indicators include memory full, active alarm state and low battery; Hygrometer equipped models include WBGT (Wet Bulb Global Temperature), Heat, Mold and Comfort indices App can trigger indicator light for unit identification Includes Certificate of Compliance, Related Products: Data Logger Thermometer, The HT200 is a Heat Stress WGBT Meter which enables accurate measurements for Wet Bulb Globe Temperature (WGBT), Black Globe Temperature (TG), Humidity (%RH), Air Temperature (TA), Wet Bulb (WT) and Dew Point (DEW). The heat brings the glass at the zone where the same is directed to flow temperature. 6 shows the thermometer blank at the moment that the heated portion has stretched to a thin strand and is separating from the upper part of the blank, the lower end of the upper part of the blank having been formed by the heating and gravity elongation of the heated zone into a downwardly tapering conical tip in which the lower end of the bores is sealed off; FIG. 11 is a schematic diagram of a heating, annealing and cooling chamber.

The minimum distance is set at 4-1/2" (114mm). The block is positioned behind a protective screen, which speeds heating and, Related Products: Melting Point Apparatus, Thomas Scientific 2022 All Rights Reserved. Thermometer has a white back, a 6 to 7mm outer diameter, and a standard taper 10/30 inner ground joint. As temperatures increase, mercury moves out of the bulbs reservoir. The column is intermittently rotated so as to intermittently move thermometer blanks 10 in relation to the stationary support disc 36. It is approximately 5 inches long. A scale scribed on the outside of the stem gives the temperature reading. Conventionally, the three sides of the thermometer essentially are flat.



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