JPH0641141Y2 - Load measuring instruments and balances - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a load measuring instrument and a balance, and in particular,
For example, the present invention relates to a load measuring instrument and a balance suitable for measuring the mass of a substance in a beaker while keeping a magnet such as a magnetic stirrer in a container such as a beaker.

<Prior Art> There is a magnetic stirrer as a device for stirring a suspension or the like contained in a beaker. This device houses a small piece of permanent magnet called a stirrer inside a beaker, and a drive mechanism provided outside the beaker magnetically rotates the stirrer to stir the suspension or the like inside the beaker. To do.

By the way, in a conventional balance, it is practically impossible to directly place the beaker containing such a magnetic stirrer on the measuring dish of the balance and measure the sample mass in the beaker, The magnetic stirrer in the beaker was taken out one by one when measuring the sample mass.

<Problems to be solved by the device> If the liquid mass can be measured with a balance etc. while the liquid and the magnetic stirrer are housed in the beaker, the measurement efficiency will improve, but it was impossible in the past. Is because the magnetic force generated by the magnetic stirrer interferes with the magnetic components inside the balance and the wall of the balance weighing chamber, or with the electromagnetic force balance balance internal magnetic circuit for load measurement. is there.

That is, as shown in FIG. 9, the magnetic force lines generated by the stirrer 21 are, for example, electromagnetic force balance type load measuring units.
31, the weighing chamber wall 32a, the weighing chamber floor 32b, or the balance case 32 such as the balance base 32c is strongly reached. As a result, even though the same beaker 20 and stirrer 21 are being measured, the balance display value fluctuates greatly each time it is placed on the measuring dish 33. The cause of this fluctuation is also that the position of the stirrer 21 in the beaker 20 changes every time.

This is particularly remarkable in a precision balance, an accurate mass value cannot be obtained, and the reproducible balance is extremely bad.

Therefore, conventionally, the magnetic stirrer 21 in the beaker 20 is taken out for each mass measurement, but this is troublesome and the work efficiency is poor as described above, and in some cases, the magnetic stirrer 21 The amount of liquid that adheres to the surface and is carried away can be a problem.

The present invention has been made in view of such a point, and an instrument capable of accurately measuring the mass and the like of a normal balance or the like while accommodating an object that generates magnetic field lines such as a magnetic stirrer, And the purpose is to provide a balance.

<Means for Solving the Problems> In order to achieve the above object, a load measuring instrument of the present invention is a container 1 made of a ferromagnetic material and a container thereof, as shown in FIG. 1 corresponding to an embodiment. It is characterized by including a non-magnetic spacer 2 housed in 1 and a piece 3 made of a ferromagnetic material provided above the spacer 2.

Here, instead of the spacer 2, as shown in FIG. 2 similarly corresponding to the embodiment, a lid body 4 made of a non-magnetic material for covering a predetermined upper portion of the similar container 1 is provided, and the lower surface of the lid body 4 is provided. A piece 3 made of a ferromagnetic material may be provided in the.

In addition, for the same purpose, the load measuring instrument illustrated in FIG. 1 or FIG. 2 may be fixed to a measuring dish or a balance may be configured to serve also as the measuring dish.

<Operation> As shown in FIG. 4, the ferromagnetic piece 3 forms a magnetic circuit having a relatively high magnetic flux density with the magnetic stirrer 21 in the beaker 20, and the spacer 2 or the lid which is a non-magnetic material. The leakage flux from the magnetic circuit described above is absorbed by the ferromagnetic container 1 existing via the space 11 formed by the body 4. As a result, the magnetism generated by the magnetic stirrer 21 in the beaker 20 hardly reaches the measuring system of the balance.

This effect is the same as in a balance in which such a load measuring instrument is fixed to or combined with a measuring dish.

<Embodiment> FIG. 1 is a plan view of a load measuring instrument according to an embodiment of the present invention (a).
It is a longitudinal cross-sectional view (b).

A container 1 made of a ferromagnetic material such as soft iron accommodates a spacer 2 made of a non-magnetic material such as foamed polystyrene or a conductive sponge. The spacer 2 is also formed of soft iron or the like. The ferromagnetic material piece 3 is arranged.

FIG. 2 is a plan view (a) and a vertical sectional view (b) of a load measuring instrument according to another embodiment of the present invention.

In this example, a lid 4 made of, for example, a non-magnetic material such as an aluminum material is provided in the same ferromagnetic container 1 in place of the spacer 2, and the ferromagnetic piece 3 is provided on the lower surface thereof. Is stuck.

FIG. 3 is a plan view (a) and a vertical sectional view (b) of a load measuring instrument according to another embodiment of the present invention.

In this example, instead of the spacer 2 of FIG. 1, a holder 5 made of a non-magnetic material such as an aluminum-based material is fixed to the bottom surface of the container 1 made of a ferromagnetic material. A piece 3 is positioned at a predetermined height inside the container 1.

In each of the above examples, the ferromagnetic piece 3 is configured to be located above the bottom surface of the container 1 by a predetermined distance via the spacer 2 or the space 11. It is more effective that the height of the peripheral edge of the container 1 is higher than the upper surface of the spacer 2 or the lid 4 or the holder 5 by a predetermined dimension.

Next, the operation of the embodiment of the present invention will be described below by taking the configuration shown in FIG. 2 as an example.

FIG. 4 shows a state in which the load measuring instrument of the embodiment of the present invention is placed on the weighing pan 33 of the balance, and the magnetic stirrer 21 and the beaker 20 containing the sample solution are placed thereon.

In this state, the magnetic lines of force generated by the magnetic stirrer 21 are short-circuited mainly by the ferromagnetic piece 3, and
Since it is further absorbed by the container 1, it hardly reaches each part of the balance, and the influence on the measured value becomes extremely small.

Here, as shown in FIG. 5, when only the load measuring instrument of the embodiment of the present invention is placed on the weighing pan 33 of the balance, it is about the same as when measuring a non-magnetized iron plate or the like. Only affected, no particular problem.

Here, as shown in FIG. 4 or FIG. 5, the load measuring instrument of the present invention can be fixed in position with respect to the balance by screwing with the measuring pan 33 of the balance on the bottom surface of the container 1. Preferably, at the same time, in this case, it is desirable to prevent the pan tray 34 of the balance from rotating. As a result, the state of the magnetic field lines generated by the magnetic stirrer 21 with respect to the balance is unlikely to change, and the influence on the measurement value is further reduced. Of course, the load measuring instrument may be fixed to the measuring dish 33 by using a double-sided adhesive tape, a so-called magic tape, a suction cup, an adhesive or the like instead of screwing.

In order to obtain reproducibility of the position of the magnetic stirrer in the beaker, it is more preferable that the ferromagnetic piece 3 in each of FIGS. 1 to 3 (a) has a rectangular shape.

Even if a balance having such a load measuring instrument is incorporated, the same effect can be expected.

FIG. 6 is a partial sectional view of the balance showing an example thereof.

In this example, the measuring pan 61 placed on the pan receiver 34 is integrated with the load measuring instrument described above. That is,
The measurement dish 61 is made of a ferromagnetic material, and is composed of a dish portion 61a for mounting on the dish receiver 34 and a container portion 61b above the dish portion 61a. Inside the container portion 61b, a lid 4 similar to that shown in FIG. A ferromagnetic piece 3 is provided.

A balance having such a measuring dish 61 can be expected to have the same operation and effect as when the load measuring instrument described above is used for a normal balance.

In addition, in each of the above-described embodiments, the ferromagnetic piece 3 may be replaced by a magnetic stirrer equivalent to the magnetic stirrer 21 housed in the beaker 20, that is, a magnetized piece. In this case, as shown in FIG. 5, when the magnetic stirrer 21 is not placed, the influence of the magnetic lines of force generated by the presence of the magnetized pieces is larger than that in the previous example. However, when the beaker 20 containing the magnetic stirrer 21 is placed, the magnetic stirrer 21 inside the beaker 20 is strongly attracted by the magnetized piece, the position of the magnetic stirrer 21 is easily determined, and the reproducibility is improved, and the measurement is performed. The magnetic flux that leaks out of the magnetic circuit formed by the magnetized piece inside the instrument and the two magnetized pieces of the magnetic stirrer 21 inside the beaker 20 is reduced, so the influence on each part of the balance in the state of FIG. 4 is reduced. This enables more stable measurement. In particular, from the state in which the magnetic stirrer 21 is placed in the beaker 20 to the state in which the object to be measured is further placed,
Since the magnetic condition does not change at all, when setting the reference load such as deleting the tare before loading the measurement object and adding the measurement object in that state and measuring the mass Is very effective at.

Further, in the example of FIG. 2, the relationship between the lid 4 and the ferromagnetic piece 3 is that the depression 71 is formed in the upper portion of the lid 4 ′ as shown in FIG. May be inserted. Similarly, in the example of FIG. 3, it goes without saying that the shape of the holder 5 is also arbitrary.

Further, the shape of the container in each example is as shown in FIG.
Of course, it is optional as shown in the perspective view in FIG.

In each of the embodiments, the spacer, the lid, the holder, or the like is made of a material such as a beaker, which is easily charged, by using a material that is an electrically conductive material. It is desirable because it can reduce the adverse effects of charging. Further, if the peripheral edge of the container 1 is higher than the position of the magnetic stirrer 21 in the beaker 20, there is an advantage that the magnetic flux leaking from the stirrer 21 is further reduced. Furthermore, if a material having a light weight such as sponge, styrofoam, or conductive sponge is used as the material of the spacer, it is convenient that the range of weighing of the balance is reduced.

<Effects of the Invention> As described above, according to the present invention, a liquid or the like to be measured is stored inside a beaker or the like while a magnetized object such as a magnetic stirrer is contained inside the beaker or the like. Even if the mass and the like are measured, it is difficult for the influence of the magnetic field lines to reach the balance measurement system or other members that cause an error (the wall of the balance weighing chamber, etc.), and the accurate mass and the like can always be measured with good reproducibility.

[Brief description of drawings]

FIG. 1 is a plan view (a) and a longitudinal sectional view showing the configuration of an embodiment of the present invention, and FIG. 2 is a plan view (a) showing the configuration of another embodiment of the present invention.
And a vertical sectional view, FIG. 3 is a plan view (a) and a vertical sectional view showing the structure of still another embodiment of the present invention, and FIGS. 4 and 5 are explanatory views of the operation of the embodiment of the present invention. FIG. 7 is a partial sectional view showing the structure of the balance of the present invention, FIG. 7 is a sectional view showing another example of the relationship between the lid and the ferromagnetic piece of the embodiment of FIG. 2, and FIG. FIG. 9 is a perspective view showing an example of the shape of the container in the example, and FIG. 9 is an explanatory view showing the influence of magnetic lines of force when a beaker containing a magnetic stirrer is measured by a conventional balance. 1 ... Container 2 ... Spacer 3 ... Ferromagnetic piece 4 ... Lid 5 ... Holder 20 ... Beaker 21 ... Magnetic stirrer 33 ... Measuring pan 61 ... Measuring pan 61a ... Plate 61b ... … Container

Claims (3)

[Scope of utility model registration request] 1. An instrument for interposing between a measurement dish of a mass or weight measuring instrument such as a balance and a sample to be measured, which is a container made of a ferromagnetic material and a non-magnetic container housed in the container. An instrument for load measurement, comprising a physical spacer and a piece made of a ferromagnetic material provided above the spacer. 2. An instrument for interposing between a measuring dish of a mass or weight measuring instrument such as a balance and a sample to be measured, which is a container made of a ferromagnetic material, and a non-cover which covers a predetermined portion above the container. A load measuring instrument comprising: a lid made of a magnetic material; and a piece made of a ferromagnetic material fixed to the lid. 3. A balance, wherein the load measuring instrument according to claim 1 or 2 is fixed to the measuring dish or also serves as the measuring dish.