CN103940481A - Laser micro-flow detection device - Google Patents

Abstract

A laser micro-flow detection device belongs to a field of micro-flow detection technology. In order to detect the micro-flow of liquid without the monitored liquid directly flowing through the flow metering device, the present invention adopts the following measures: a laser emitting tube (5) and a laser receiving head (6) are respectively installed on both sides of a transparent drip tube (4), the laser emitting tube (5) is connected to a laser signal generator, the laser receiving head (6) is connected to a laser signal processing circuit, the laser signal processing circuit is connected to a single-chip microcomputer, and the single-chip microcomputer is connected to a display screen (3); the laser signal processing circuit described here refers to a circuit device that can convert the electrical signal generated by the laser receiving head when the water droplets flow through the transparent drip tube into an electrical signal that can be recognized by the single-chip microcomputer; the advantage of this is that since laser technology is used to "read" the liquid drip flow information, the detected liquid is non-contact when detecting the liquid flow. The corrosion of the instrument by the liquid is avoided.

Description

Laser micro flow detection device

technical field

The invention belongs to the field of micro flow detection technology.

Background technique

In many technical fields such as industrial automatic control, medical treatment, laboratory, etc., it is necessary to detect and control the flow of micro-flow liquid. However, because it is a micro-flow, its flow rate is very slow, the flow rate per unit time is very small, and its flow force is not even enough to drive the instrument. Therefore, it is almost impossible to accurately detect and measure by conventional means. In some special occasions, such as the field of medical technology, it is necessary to detect and measure the micro-flow medicinal liquid for precise manual or automatic control. However, the flowmeters used in the prior art are not only unable to measure the micro-flow rate of the liquid medicine, but also require the liquid medicine to be measured to flow through the flowmeter. This is not allowed for medical drugs, because it is easy to cause pollution of the liquid medicine. Therefore, in the prior art, no suitable micro-flow detection device has been found in the field of medical technology so far.

On the other hand, in industries, especially in the chemical industry and other technical fields that require automatic control based on micro-flow, laboratories, etc., many places need to detect liquids with highly corrosive micro-flow as the basis for automatic control or flow recording . These liquids are generally very corrosive or highly toxic, and they also precipitate and crystallize, which can seriously damage the flowmeter. It is difficult for ordinary flow meters to measure it. As a result, this aspect is still a blank.

Contents of the invention

In order to be able to detect the micro-flow rate of the liquid under the premise that the monitored liquid does not directly flow through the flow metering device, the present invention takes the following measures: a laser emitting tube and a laser receiving head are respectively installed on both sides of the transparent drip tube, and the laser emitting tube Connect the laser signal generator, the laser receiving head is connected to the laser signal processing circuit, the laser signal processing circuit is connected to the single-chip microcomputer, and the single-chip computer is connected to the display screen; the laser signal processing circuit mentioned here refers to the output of the laser receiving head, and the water droplets flow through the transparent drip A circuit device that converts the electrical signal generated during the cartridge into an electrical signal that can be recognized by a single-chip microcomputer.

The advantage of this is that the laser micro-flow detection device of the present invention uses laser technology to "read" the liquid dripping information, so when detecting the liquid flow, it is non-contact to the liquid to be detected. That is to say, the present invention can also measure the micro-flow rate of the liquid under the condition that the liquid can still keep circulating in its own pipeline without directly contacting the measuring device. In this way, secondary pollution of the liquid to be detected by the measuring device can be avoided, and corrosion of the instrument by the corrosive liquid can also be avoided. This device can monitor the flow and total flow per unit time at any time through the single-chip microcomputer, so that the user can know the change of the flow in time. Therefore, such a device is of great significance for use in the medical field.

Description of drawings

Fig. 1 is a schematic structural diagram of a laser micro-flow detection device.

Fig. 2 is a schematic diagram of the circuit structure of the laser micro-flow detection device.

In the figure: flow regulator 1, drip hose 2, display screen 3, transparent drip tube 4, laser emitting tube 5, laser receiving head 6.

Detailed ways

In the present invention, a laser emitting tube 5 and a laser receiving head 6 are respectively installed on both sides of the transparent drip tube 4 . The laser emitting tube transmits laser pulse signals to the laser receiving head 6 through the transparent drip tube 4 . When liquid drips downwards above the transparent drip tube 4 and passes through the emission path of the laser, the laser beam is scattered and blocked by the liquid drop. At this time, the intensity of the laser signal obtained by the laser head changes, causing the electrical signal output by the laser receiving head to also change, and these changes can accurately reflect the flow of the droplet.

The laser receiving head 6 is connected with a laser signal processing circuit. The laser signal processing circuit mentioned in this application refers to a circuit device that can convert the electrical signal output by the laser receiving head and generated when water droplets flow through the transparent drip tube into a pulsed electrical signal that can be recognized by a single-chip microcomputer. The present invention has no special requirements on the laser signal processing circuit, and the form of the laser signal processing circuit is various, and they can have different structures and different combinations.

To facilitate the description of the working principle of the present invention, this embodiment takes the injection of a needle in the medical field as an example. First hang the medicine bottle on the hook, then connect the drip tube rubber tube 2, and then clamp the transparent drip tube 4 between the laser emitting tube 5 and the laser receiving head 6, as shown in Figure 1. After the nurse let go the air in the drip tube 2 and connected the needle to the patient's venous blood vessel, the flow regulator 1 could be opened, and at this moment the medicinal liquid began to drip down from the top of the transparent drip tube 4 . Turn on the power switch of the laser micro-flow detection device, and the circuit starts to work. The laser emitting tube 5 emits laser pulses to the laser receiving head 6 . When the drops of medicinal liquid drip down from the top of the transparent drip tube 4, the drops flow through the emission path of the laser light, causing scattering and refraction of the laser light when the laser light is irradiated on the water drops. It deflects the laser that originally reached the laser receiving head, and its energy is greatly reduced. The reduction of laser energy changes the electrical signal output by the laser receiving head. These changes can truly and accurately reflect the flow of droplets. The laser receiving head is connected to the laser signal processing circuit, and the laser signal processing circuit is connected to the single-chip microcomputer, as shown in Figure 2. The laser signal processing circuit converts the electrical signal output by the laser receiving head into an electrical signal that can be recognized by the single-chip microcomputer, which represents the pulse electrical signal that the water droplet flows through, and then sends it to the single-chip microcomputer. According to the established procedure, the single-chip microcomputer calculates the number of drops per minute according to the time between the two drops and displays them on the display screen for the nurse lady as a reference for adjusting the flow regulator 1 . This greatly shortens the time for adjusting the flow rate and reduces the labor intensity of nurses. On the other hand, the single-chip microcomputer can set the alarm program. For example, when the flow is not detected within a certain period of time, it can be considered that the rubber hose is blocked by pressure or the liquid medicine is finished, and the single-chip microcomputer can immediately start the alarm program and send the alarm to the nurse for handling. When the flow rate is greater than the set value, the single-chip microcomputer can also start the alarm program and the alarm is also handled by the nurse.

Claims (1)

1. laser micrometeor pick-up unit, mainly comprise LASER Discharge Tube (5), laser pick-off head (6), display screen (3) composition, it is characterized in that: LASER Discharge Tube (5) and laser pick-off head (6) are installed respectively on the both sides of transparent drop cylinder (4), LASER Discharge Tube (5) connects laser signal generator, laser pick-off head (6) connects laser signal treatment circuit, laser signal treatment circuit connects single-chip microcomputer, and single-chip microcomputer connects display screen (3); Laser signal treatment circuit described here refers to can be by laser pick-off head output, and the electric signal that water droplet produces while flowing through transparent drop cylinder changes the circuit arrangement of the electric signal that single-chip microcomputer can identify into.