Method for detecting liquid level by image method and device

Abstract

The invention discloses a method for detecting liquid level by an image method and a device. The method comprises the following steps: illuminating the inner liquid level and the inner wall of a test tube to be tested; linking an arc tangent point at one side of the bottom of the test tube to be tested toward an inner edge at the other side of a test tube opening and extending the link to form a first extension line, making a second extension line parallel to the first extension line by passing through the inner edge of one side of the test tube opening, arranging a lens plane of a digital camera vertical to the first extension line and the second extension line, and aligning the lens to a whole side edge of the inner wall of the test tube for shooting; and obtaining the distance from an inside point at the top end of the test tube to an interface of the liquid level and the test tube wall through the digital camera so as to calculate a height value of the liquid level in the test tube to be tested through a formula. The method and the device have the advantages that the method and the device are not influenced by the electric conductivity of the sampled liquid or influenced by labels and stains on the outer wall of the test tube, and can detect whether bubbles on the liquid level and a bottle cap are removed.

Description

technical field [0001] The invention relates to a non-contact liquid level detection method, especially in analytical instruments that require automatic micro-sampling and adding of liquids, such as automatic biochemical analyzers, automatic enzyme-labeled immune analyzers, blood viscosity meters, blood coagulation instruments, etc. A liquid level detection method and device for an analyzer, etc. Background technique [0002] Analytical accuracy is the most important indicator of automatic analytical instruments. Among the many factors affecting the analysis accuracy, the sampling accuracy is the most important factor. In the automatic analysis instrument, the micro-sampling of liquid samples and reagents is mostly done by probing the liquid through the sampling needle. Then it is injected into the cuvette or cuvette for subsequent measurement. During the sampling process, the tip of the sampling needle cannot be immersed in the liquid to be sampled too deeply, otherwise ...

AI Technical Summary

Problems solved by technology

The biggest disadvantage of the contact type is: 1. Physical properties such as the conductivity of the liquid affect the detection accuracy of the liquid level; 2. Bubbles on the liquid surface will cause inaccurate sample addition; 3. When the liquid to be sampled is exhausted, the detection device must be completed. Only by detecting the action can we know that the liquid has been exhausted, and this action becomes an invalid action, thus reducing the speed of the instrument; 4. When the bottle cap of the container is forgotten to be removed, the cap may damage the sampling needle

The biggest disadvantage of this method is that it can only be used in transparent test tubes, and there must be no stains on the inner and outer walls of the test tubes. However, the outer surfaces of the test tubes used in clinical practice are all pasted with paper labels or blood stains. Where to use the method

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