JPH04258724A - Volume measuring device - Google Patents

Abstract

PURPOSE:To correctly measure the volume of a cavity and the volume of the residual substance accommodated inside, independently of the existence of the residual substance in a container, by one measurement work. CONSTITUTION:A flow passage selector valve 1 which selectively supplies measurement gas and carrier gas through an inflow pipe 11 and a discharge pipe 12 which are connected with a measured vacant body S, gas detector 9 connected with the discharge pipe 12, and an integration circuit 10 for integration- calculating the signal supplied from the gas detector 9 are provided. The measurement gas which is confined in the measured vacant body S through the inflow pipe 11 is discharged into the gas detector 9 through the discharge pipe 12, together with the carrier gas. At this time, the integration value of the output of the gas detector 9 becomes equal to the volume of the measurement gas accommodated in the measured vacant body S, the volume of the measured vacant body S can be known.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring the internal volume of containers, cylinders, holes, etc.

0002

2. Description of the Related Art When measuring the volume of an irregularly shaped object having an uneven surface, etc., the object to be measured Q is housed in a sample chamber A having a constant volume V1 as shown in FIG. After setting the pressure to a constant pressure P1, the sample chamber A is opened to communicate with the expansion chamber B having a constant volume V2 by opening the valve C, and the pressure P2 at this time is measured. From these pressures P1, P2, V1, and V2, the volume Vs of the object to be measured Q is determined as V1-V2/{(P1/P2)-1} based on Boyle-Charles' law.

0003

[Problem to be Solved by the Invention] However, in order to measure the volume of a cavity formed by a container, tube, hole, etc. in an irregularly shaped object, it is necessary to measure the volume of the irregularly shaped object itself and the volume with the opening closed. It is necessary to measure and find the difference between them,
In addition to the problem of time-consuming measurement, if volatile substances remain in the cavity, or if you try to measure the volume of volatile substances or the volume of the cavity with volatile substances contained, There is a problem in that the pressure changes due to the vapor pressure of the sexual substance, and the measurement results include errors.

[0004] The present invention was made in view of these problems, and its purpose is to determine the volume of a cavity and the amount of material contained inside it in a single measurement operation, regardless of the presence or absence of residual substances. An object of the present invention is to provide a novel volume measuring device that can accurately measure the volume of residual substances.

[0005]

[Means for Solving the Problems] In order to solve such problems, the present invention selectively supplies the measurement gas and the carrier gas through an inflow pipe and a discharge pipe connected to the hollow body to be measured. The apparatus includes a supply flow path switching means, a gas detection means connected to the discharge pipe, and a means for integrating a signal from the gas detection means.

[0006]

[Operation] The measurement gas confined in the hollow body to be measured via the inflow pipe is discharged by the carrier gas to the gas detection means via the discharge pipe. The output of the gas detection means at this time represents the concentration, but its integral value is the volume of the measurement gas contained in the cavity to be measured, so by calculating the integral value, the volume of the cavity to be measured is determined. can be known.

In this process, even if the substance remaining in the cavity to be measured evaporates and the internal pressure changes, the volume of the measurement gas itself does not change at all, so the residual substance is the cause of the measurement error. It won't be.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be explained below based on illustrated embodiments. FIG. 1 shows an embodiment of the present invention, in which reference numerals 1 and 2 are first and second switching valves, respectively, and a first flow path is indicated by a solid line in the figure, and a first flow path is indicated by a dotted line. A second flow path is configured, and the first and second
When the first flow path (the flow path indicated by the solid line in the figure) is selected by the switching valves 1 and 2, the measurement gas, such as a gas that is easy to detect such as helium or hydrogen, flows from the measurement gas inlet 3 to the first flow path. 2 into the switching valve 2. The second switching valve 2 is connected to a third switching valve 4 through which measuring tubes 5, 6 with different capacities are connected.
7 is connected, a suitable metering tube 6 is used to accommodate a known amount of measuring gas in the metering tube 6.

In this state, the second switching valve 2 is connected to the second flow path (
When switching to the flow path shown by the dotted line in the figure), the measurement gas is sealed in the metering tube 6. Next, when the first switching valve 1 is switched to the second flow path (the flow path indicated by the dotted line in the figure),
After the carrier gas such as nitrogen flows from the carrier gas source 8 through the first switching valve 1 and the second switching valve 2 to the third switching valve 3, it passes through the first switching valve 1 and changes its thermal conductivity. The measuring gas flows into a gas detector 9 such as a detector, and the measuring gas remaining in the flow path is purged.

When the second switching valve 2 is switched to the first flow path (the flow path indicated by the solid line in the figure) when the purge is completed, the carrier gas passes through the third switching valve 4 and enters the metering tube 6. The gas for measurement flowing in and contained therein is discharged to the gas detector 9 via the second and first switching valves 2 and 1. By integrating the output of the gas detector 9 (FIG. 2) at this time using the integrating circuit 10, the relationship with a known amount of measurement gas can be calibrated.

When performing measurement, the hollow body S whose volume is to be measured is connected to the second switching valve 2 via the inflow pipe 11 and the discharge pipe 12, and the first switching valve 1 is connected to the first flow path. (flow path indicated by a solid line) and the second switching valve 2 is switched to the second flow path (flow path indicated by a dotted line) and the measurement gas is injected into the hollow body S via the second switching valve 2. flows into. Next, when the first switching valve 1 is switched to the second flow path and carrier gas is injected, the measurement gas confined in the cavity S is discharged to the gas detector 9 by the carrier gas. The output from the gas detector 9 is integrated by an integrating circuit 10 and sent to the hollow body S.
is output as the volume of Needless to say, since the volume of the measuring gas confined in the hollow body S matches the internal volume of the hollow body S, the measurement can be completed in one measurement operation.

[0012] Furthermore, even if the hollow body S contains a highly volatile substance such as an organic solvent, a gas detector capable of selectively detecting the measurement gas and the volatile substance is provided. If used, the total amount of measurement gas contained in the hollow body S can be detected, so the spatial volume of the hollow body,
Alternatively, the amount of organic solvent can be measured.

[Example] Measurement was carried out with 250 microliters of ethanol contained in a tester with an internal volume of 2.1384ml, and the space volume of the tester was 1.
．． A measurement value of 8844 milliliters was obtained, resulting in a total amount of ethanol contained in the test tube of 254 microliters. From this, it was found that even if easily vaporized substances were attached, it was possible to measure the volume of the contained easily volatile substances and the internal volume of the glass test tube body without being affected by the vapor pressure of these substances. .

[0014]

[Effects of the Invention] As explained above, in the present invention,
A flow path switching means for selectively supplying a measurement gas and a carrier gas through an inflow pipe and a discharge pipe connected to the hollow body to be measured; a gas detection means connected to the discharge pipe; Since the gas detecting means is equipped with a means for integrating the signal, the volume of the hollow body can be measured in one operation by integrating the amount of detectable measurement gas contained in the hollow body to be measured using the gas detection means. In addition, even if a highly volatile substance remains in the hollow body, it is not affected by the vapor pressure of the residual substance, making it possible to accurately measure the volume or the spatial volume of the hollow body to be measured. can.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of an apparatus showing an embodiment of the present invention.

FIG. 2 is a diagram showing the output from a gas detector in the same device.

FIG. 3 is an explanatory diagram showing a conventional method for measuring the volume of a foreign object.

[Explanation of symbols]

1, 2 Switching valve 3 Gas inlet for measurement 5, 6, 7 Measuring tube 8 Carrier gas source 9 Gas detector S　Cavity body to be measured

Claims (1)

[Claims] 1. A flow path switching means for selectively supplying a measurement gas and a carrier gas through an inflow pipe and a discharge pipe connected to a hollow body to be measured; and a gas detection means connected to the discharge pipe. , a volume measuring device comprising means for integrating a signal from the gas detection means.