JPH0225140Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a device for measuring an ultra-trace amount of liquid, for example, a liquid amount of 10 μm or less.

BACKGROUND TECHNOLOGY As a method for measuring the secretion of an ultra-trace amount of liquid, such as tears, a method has been proposed in which the liquid to be measured is sucked from one end of an extremely thin cotton thread, and the amount of liquid is measured by the wetted length of this cotton thread.

Problems that the invention aims to solve However, the method of using ultra-fine cotton thread as a measuring tool has the following drawbacks.

(i) Evaporation of the measurement liquid occurs on the cotton thread, and the measurement value is affected by the measurement environment, which tends to cause measurement errors.

(ii) Measurement of the wet length of the cotton thread requires the use of a meter, which is cumbersome.

(iii) Oils and fats from hands and fingers tend to adhere to the cotton thread and adversely affect measurements.

The present invention was made with the aim of eliminating these conventional problems.

Means for Solving the Problems The present invention is characterized in that an ultra-fine measuring cotton thread for measuring the amount of ultra-trace liquid by wet length is housed in a transparent microtube with graduations. This relates to an ultra-trace liquid measuring device.

Embodiment An embodiment of the present invention will be described below with reference to the accompanying drawings.

In the figure, 1 is an ultra-fine cotton thread. From a performance standpoint, the cotton thread 1 should be as thin as possible, but due to manufacturing restrictions, it is usually about 0.2 to 0.4 mm in diameter. used. Depending on the amount of liquid to be measured, a thicker one may be used. cotton thread 1
It is preferable to use a material with as good water absorption as possible.
Cotton yarn obtained by the manufacturing method according to No.-183134 can be used. The effective length of the cotton yarn 1 is not particularly limited, and is usually appropriately selected from a range of about 100 to 200 mm.

Reference numeral 2 denotes a microtubule for storing the cotton thread 1, and the microtube 2 has a diameter slightly smaller than the diameter of the cotton thread 1, for example, by 0.1 to 0.2 mm, in consideration of workability when inserting the cotton thread 1 into the tube.
One with a relatively large inner diameter is used. The microtubule 2 is transparent and has a scale 3, and such a microtubule 2 is preferably molded from a synthetic resin with as high transparency as possible, such as acrylic resin.

One end of the cotton thread 1 housed in the microtubule 2 is fixed to the rear end of the microtube 2 by welding or other appropriate means to prevent it from slipping out. The other end of the cotton thread 1 is exposed from the other end of the microtubule 2 for the purpose of immersion in the measurement liquid, and if the length of the exposed portion 1a is too long, it may adversely affect measurement performance. Therefore, the length should be kept to one-tenth or less of the effective length, and is usually selected appropriately from the range of about 0 to 10 mm.

The ultra-trace liquid measuring device according to the present invention consists of measuring cotton thread 1
is contained within the microtubule 2, so that evaporation of the measurement liquid on the cotton thread 1 during measurement can be substantially eliminated.

FIG. 2 is a graph showing the water absorption lengths of 1 μ, 2 μ, and 3 μ, comparing the product of the present invention using microtubules 2 and the conventional product without using microtubules 2. In Fig. 2, A shows the product of the present invention and B shows the conventional product.

As is clear from Fig. 2, compared to the conventional product, the water absorption values of each μ are in a linear relationship, and the water absorption values of each μ are larger, and the slope of the straight line is larger, and even for small liquid volumes, the water absorption values of each μ are larger. Shows sensitivity to change,
Can measure more accurately than conventional products. In Figure 2, the broken line indicates the collapse of the linear relationship in the conventional product.
It is thought that when the liquid volume increases to 2 to 3 microns, the influence of evaporation appears and the linear relationship breaks down.

FIG. 3 compares the water absorption over time between product A of the present invention and conventional product B, and also shows the influence of differences in the measurement environment (humidity) on the water absorption value. The measurement is done in the fourth
Apply the rising method shown in the figure, and the humidity of 60% is indicated by the solid line.
86% is indicated by a broken line. As is clear from Figure 3, the water absorption value of the product of the present invention constantly increases as time passes, whereas the conventional product shows more than 80% of the final water absorption value in 2 minutes, and almost no increase in 4 minutes. This occurs because the amount of evaporation exceeds the amount of water absorbed. This is the measurement environment (humidity) in the same figure.
This can also be explained from the water absorption value due to the difference in humidity, and the product of the present invention is less affected by humidity, whereas the conventional product is greatly affected.

FIG. 5 is also a graph examining the influence of evaporation, and shows the exposed part 1a of the cotton thread 1 from the microtubule 2 from 0 to
When changing to 10 mm, the water absorption value decreases by about 25% in the case of 10 mm compared to the case of 0, and it can be seen that evaporation has a large influence on the water absorption value.

As described above, according to the present invention, the influence of evaporation and the measurement environment (humidity) on the water absorption value can be extremely reduced.

Furthermore, since the scale 3 is attached to the microtubule 2, there is no need to apply a measuring instrument.

Furthermore, during the measurement operation, the cotton thread 1 can be separated from the fingers and fingers by the microtubule 2, so that it is possible to prevent oily fingers from adhering to the cotton thread 1.

In the present invention, the wetted length of the cotton thread 1 can be easily read visually when the liquid is colored, but it is difficult to read when the liquid is colorless, which is inconvenient. Therefore, in such cases, if the measuring solution is acidic or alkaline,
It is convenient to color the cotton thread 1 in advance with the corresponding indicators. In addition, in the case of a neutral liquid, a dye such as fluorescein is added to the cotton thread in advance.
The dye may be colored in advance, and the dye may be dissolved and transferred into the measurement liquid sucked into the cotton thread 1.

Effects As described above, according to the present invention, it is possible to extremely reduce the influence of evaporation and the measurement environment on the water absorption value, and it is also possible to prevent oils and fats from adhering to the cotton thread 1, making it possible to perform accurate measurements and improve performance and quality. can be significantly improved. Furthermore, measure the wet length of cotton thread 1.
Since it can be performed directly from the scale 3 attached to the microtubule 2,
The application of instruments becomes unnecessary and operability can be improved.

[Brief explanation of drawings]

Figure 1 is a perspective view showing one embodiment of the present invention;
The figure is a graph showing the results of a water absorption length comparison test between the product of the present invention and a conventional product, Figure 3 is a graph showing the results of a comparison test of water absorption over time, and Figure 4 is a diagram showing the test method. FIG. 5 is a graph showing the relationship between exposed length of cotton yarn and water absorbency. In the figure, 1 is a cotton thread, 2 is a microtubule, and 3 is a scale.

Claims (1)

[Scope of utility model registration request] An ultra-trace liquid measuring device characterized in that an ultra-fine measuring cotton thread for measuring the amount of ultra-trace liquid by wet length is housed in a transparent microtube with graduations.