JPH081478Y2 - Specific gravity measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an apparatus for determining the specific gravity of a sample by measuring the aerial weight and the in-liquid weight of the sample.

<Prior Art> A general specific gravity measuring device is an electronic balance for measuring the weight of a sample in air or in liquid, a liquid tank used for measuring the weight in liquid and its vertical movement device, and in air and liquid. And a calculation unit for calculating the specific gravity from the result of measuring the middle weight.

The in-liquid weight of the sample is measured by placing the sample on the lower plate supported by the suspension core suspended from the balance, raising the liquid tank in this state, and immersing the suspension core to the specified position in the liquid. To be done.

The weight of the sample in the air is measured by placing the sample in the air on either the lower pan or the upper pan provided on the same balance.

<Problems to be solved by the invention> By the way, when measuring the weight of a sample in liquid, the surface tension of the liquid received by the suspension core fluctuates instead of being constant.
There is a problem that the accurate and in-liquid weight cannot always be obtained stably, and as a result, the accuracy of the obtained specific gravity value becomes poor.

<Means for Solving the Problems> The specific gravity measuring device of the present invention is provided with a means for rippling the liquid surface in the vicinity of the fishing rod immersed in the liquid tank, and after immersing the lower plate and the fishing rod in the liquid, It is characterized in that the liquid surface in the vicinity of the fishing lead is undulated before collecting the in-liquid weight data.

<Operation> The reason why the surface tension of the fishing rod received from the liquid surface is not constant is that the surface state of the fishing rod near the liquid surface before immersion is not constant. That is, there is a difference in the surface tension received from the liquid when the fishing lead is dry and when it is wet. The wet state of the surface of the hanging core also differs depending on, for example, whether or not the hanging core enters in a swaying state with respect to the liquid.

The present invention has been made paying attention to this point, and the liquid surface in the vicinity of the fishing lead is undulated until the in-liquid data is collected with the fishing lead immersed in the liquid surface up to a predetermined position. By so doing, the wetting of the suspension core is always kept constant, and an accurate weight measurement value in the liquid with less repetitive error is to be obtained.

<Embodiment> The drawings are front views showing the construction of an embodiment of the present invention.

An electronic balance 2 having an upper plate 2a and a lower plate 2b is placed on the ceiling surface of the gantry 1, and the lower plate 2b penetrates the ceiling surface of the gantry 1 by the hanging core 2c and reaches the inside of the gantry 1. .

A liquid tank device including a liquid tank 3 and an elevator device 4 for vertically moving the liquid tank 3 is arranged inside the gantry 1. The liquid tank 3 is driven by driving the elevator device 4.
The position of is either one of two states: the lower plate 2b is immersed in the liquid as shown by the solid line in the figure, and the lower plate 2b is not immersed as shown by the chain double-dashed line in the figure. .

Here, the liquid tank 3 is filled with the liquid to a predetermined level in the used state, and when the elevator device 4 is in the raised state, the liquid level L of the liquid tank 3 is always at a fixed position of the suspension core 2c. ing.

The vibrator 5 is fixed to the lower surface of the ceiling surface of the gantry 1, so that the tip of the vibrator 5 sinks slightly below the liquid level L of the liquid tank 3 when the liquid tank 3 is raised. There is.

The electronic balance 2, the elevator device 4, and the vibrator 5 described above are connected to an arithmetic control unit 6 including a personal computer and its peripheral devices, a drive circuit, and the like, and these units are controlled by the procedure described below.

First, the weight of the sample in air is measured. In this measurement, the liquid tank 3 is lowered and the sample is placed on the upper plate 2a of the electronic balance 2.
Or by placing it on the lower plate 2b. The measurement data of the weight in air is taken in and stored in the arithmetic control unit 6.

Next, the liquid tank 3 is raised by operating a switch or the like (not shown) with the sample placed on the lower plate 2b. As a result, the liquid surface L rises to a predetermined position on the hanging core 2c, but at the same time, the tip of the vibrator 5 is immersed in the liquid surface L.

In this state, the vibrator 5 is automatically activated and stopped after being driven for a certain period of time. As a result, the liquid surface L becomes wavy, and the hanging core 2c gets wet in a predetermined range around the vicinity of the liquid surface L. When the vibrator 5 stops, the liquid level L will come to a standstill, but this standstill state is detected by a monitor of the output of the electronic balance 2 and the weight data is determined to be stable. That is, the in-liquid weight of the sample is taken in and stored in the arithmetic control unit 6.

The arithmetic control unit 6 calculates the specific gravity of the sample from the in-liquid weight data and the in-air weight data of the sample previously taken. At this time, a known correction calculation based on the buoyancy force received by the suspension core and the lower tray, the surface tension, and the like set in advance is also performed.

The points to be noted in the operation of the embodiment of the present invention are as follows.
It means that the vicinity of the liquid surface L of the suspension core 2c is always wetted by the drive of the vibrator 5 before the in-liquid weight data is taken into the arithmetic control unit 6. As a result, the force applied to the suspension core 2c due to the surface tension of the liquid surface L does not change and is always constant, and the specific gravity value of the sample is stably and correctly corrected by the correction calculation described above.

The above-described amplitude of the vibrator 5 may be maintained at a constant amplitude after starting, and may be stopped by keeping the amplitude for a certain period of time, or the amplitude after starting may be attenuated with time.

Further, in the present invention, as means for making the liquid surface L wavy,
Other means such as a rotor can be adopted in addition to the vibrator as in the above-described embodiment.

<Effects of the Invention> As described above, according to the present invention, before collecting the in-liquid weight data, the hanging surface of the lower tray is soaked in the liquid surface that the suspension core is soaked in the liquid surface that the suspension surface is swelled. Since the surface of the core is always in a constant wet state, the force that the hanging core receives due to the surface tension of the liquid surface is almost constant, and the weight value in liquid of the sample is always corrected correctly by a constant correction calculation. The specific gravity value obtained is also stable and accurate with little repetition error.

Here, by making the suspension core extremely thin, the influence of the surface tension received from the liquid surface is reduced, but when the suspension core is thin, the lower dish becomes unstable and it becomes difficult to place and lower the sample on the lower dish. . By adopting the present invention, it is possible to perform high-accuracy specific gravity measurement with less repetitive error even if a thick core is used without using a thin core that makes the lower plate unstable.

[Brief description of drawings]

 The drawing is a front view showing the configuration of the embodiment of the present invention. 1 ... Stand 2 ... Electronic balance 2a ... Top plate 2b ... Bottom plate 2c ... Spindle core 3 ... Liquid tank 4 ... Elevator device 5 ... Transducer 6 ... Calculation control unit L ... Liquid level

Claims (1)

[Scope of utility model registration request] 1. A balance comprising a lower plate suspended from a suspension core, and a liquid tank device for immersing the lower plate, wherein the weight of the sample to be measured in air and the lower plate are provided. In the device for obtaining the specific gravity of the sample from the measurement result with the in-liquid weight of the sample measured by immersing the sample to the predetermined position in the liquid with the sample to be measured, in the liquid tank device It is provided with a means for rippling the liquid surface in the vicinity of the immersed fishing core, and is configured to ruffle the liquid surface after the immersion of the lower plate and the fishing rod and before collecting the in-liquid weight data. A specific gravity measuring device characterized in that