JPH0430509Y2 - - Google Patents

Description

[Detailed explanation of the invention] Conventionally, when measuring body temperature with a thermometer, in order to return the thermally expanded temperature-sensitive medium (mercury, etc.) to its original state, the thermometer was held in the hand and shaken, or the thermometer was placed in a storage container and the string was twisted and rotated. If the patient were to apply centrifugal force to the patient himself, it would have to be a very difficult movement. Or you may forget to put it back and the mercury column becomes intermittent.

In the present invention, after taking a measurement, if the thermometer is stored in the storage container, the temperature-sensitive medium automatically returns to the reference point. An example will be explained using figures. 1st
The figure shows an external view of a thermometer, in which a glass rod 3 having a storage part 2 for a temperature-sensitive medium 1 at the bottom has a vacuum hollow part 4 inside, and the storage part 2 and the hollow part 4 are connected to a constriction part 5. A transparent container in which the temperature-sensitive medium 1 is sealed is formed. The glass outer cylinder 6 integrally houses the scale plates 7 and 3 and is configured as a normal thermometer. When a magnetic fluid with good thermal conductivity is used as the temperature-sensitive medium 1, it is possible to exhibit the feature of automatically returning a thermally expanded medium to a reference point as described later. A magnetic fluid is a liquid in which fine particles of oxides such as iron oxide or fine particles of metals such as iron, cobalt, or alloys thereof are dispersed in a liquid. There are some that use oil and some that use mercury. For thermometers, it is preferable to use a mercury-based metal magnetic fluid, taking into consideration not only thermal conductivity but also the ability to cut the fluid to the glass surface, the adhesion of the fluid, and the like. FIG. 2 is a longitudinal cross-sectional view of the storage container, showing the state in which the thermometer is stored.
A case 8 and a case cover 9 made of plastic or the like are connected by a threaded portion 10 to complete an integrated structure as a container. Stopper 11 inside the case
A permanent magnet 12 is attached nearby. As shown in Figure 2, when the thermometer is stored, the magnetic fluid 1 has thermally expanded.
is magnetized by the permanent magnet 12 and automatically pulled back to the reference point. The heat generated by magnetization compression and the heat generated by body temperature are naturally radiated through the glass. One of the ways in which mercury has traditionally been used as a temperature-sensitive medium is
This is because this natural heat dissipation is suitable for processing compression heat and heating. However, if the mercury column is not returned to the reference point promptly, it will shrink due to heat radiation, causing the inconvenience that the mercury column will be cut vertically at the constriction portion or the mercury column will become discontinuous. Conventionally, as shown in Fig. 3, a string attached to the storage container was twisted and the storage device was rotated by pulling it from side to side with fingers to apply centrifugal force. In this case, the force f is given as rotation radius 7 cm, mercury 0.05 cc, and 10 revolutions/second = mv ² / r = 13.55 × 0.05 / (980
×7)×(2×7×π×10) ² ≈19.1g The saturation magnetization value of the magnetic fluid used in the present invention is about 200 (oxide magnetic fluid) to 1500 (metallic magnetic fluid) Gauss.

If it is 1000 Gauss, the suction force F is (A = storage part 2
Inner peripheral area ≒ 0.785cm ² , H = 1000 Gauss, magnetic permeability of air μ = 1) F = μH ² A / 8π = 1 × 1000 ² × 0.785 / 8π =
31235 dyne≒31.87 gF>, which is sufficient for this example.

In this way, simply by storing the thermometer in the storage container, the temperature-sensitive medium easily and automatically returns to the reference point and is always kept in a reusable state.

[Brief explanation of the drawing]

FIG. 1 shows the outer shape of the thermometer of the present invention, and FIG. 2 is a vertical sectional view of the thermometer storage device, showing the state in which the thermometer is stored. FIG. 3 is an external view of a conventional storage device, showing the case where the storage device is rotated by twisting a string attached to the case and pulling the string from side to side with one's fingers. 1... Temperature-sensitive medium (magnetic fluid), 7... Scale plate,
2...Reservoir, 8...Case, 3...Glass rod, 9
... Case cover, 4 ... Hollow part, 10 ... Threaded part, 5 ... Throttle part, 11 ... Stopper, 6 ... Glass outer cylinder, 12 ... Permanent magnet.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A thermometer that uses a magnetic fluid with good thermal conductivity as a temperature-sensitive medium and is sealed in a transparent container such as glass;
A body temperature measurement device consisting of a thermometer storage device with a permanent magnet attached to a part of the case or case cover to automatically return the temperature-sensitive medium to a reference point. (2) The body temperature measurement device according to the preceding item 1, which uses a mercury-based metal magnetic fluid as the magnetic fluid with good thermal conductivity.