Automatic trace instrument

Abstract

The utility model relates to the technical field of trace instruments, in particular to an automatic trace instrument which comprises a bottom shell, a pressure sensor is mounted in the bottom shell, a measuring bin is mounted on the upper side of the bottom shell on the upper side of the pressure sensor, a windproof cover used for covering the measuring bin is arranged on the upper side of the bottom shell, and a light source is mounted on the side face of the windproof cover. A photosensitive sensor is installed on the inner top of the windproof cover, the sensing face of the photosensitive sensor is arranged downwards, a light shielding plate is installed on the lower side of the photosensitive sensor, a first light through hole penetrating up and down is formed in the light shielding plate, and a reflector used for reflecting light emitted by the light source into the first light through hole is installed on the upper side of the measuring bin 1. When the measuring bin inclines, the reflecting mirror inclines along with the measuring bin, so that the reflecting angle and the reflecting direction are changed, and light rays generated by the light source cannot irradiate the photosensitive sensor through the first light through hole after being reflected.

Description

Technical Field

[0001] The utility model relates to the technical field of trace meters, in particular to an automatic trace meter. Background Art

[0002] Trace: A very small amount, so small that it's barely noticeable. In applied science, a substance's concentration is considered to be less than one part per million. Trace is also used in chemistry, materials science, and biomedicine. For example, in the field of mass spectrometry, a trace refers to an amount less than 10e-6.

[0003] The volumetric tracer is a new type of instrument used to calibrate ultra-micro dynamic pipetting of automated pipetting equipment, with a pipetting accuracy of up to nL level.

[0004] As disclosed in application number 202311027098.5, a trace meter and a dynamic ultra-micro pipetting device calibration method are disclosed. The trace meter includes a measuring chamber, a temperature sensor, a pressure sensor and a controller. An opening is set above the measuring chamber, the temperature sensor is set at the bottom of the measuring chamber, and the pressure sensor is set below the measuring chamber. The temperature sensor and the pressure sensor are both electrically connected to the controller. The temperature sensor is used to measure the temperature of the liquid inside the measuring chamber, and the pressure sensor is used to measure the weight of the liquid inside the measuring chamber.

[0005] In the above patent, since the load-bearing plate needs to measure the weight of the measuring chamber, the side and bottom shell of the load-bearing plate cannot be fixed to avoid affecting the measurement results. The pressure sensor is completely relied upon to keep the entire measurement process in a vertical state. Therefore, during use, it is inevitable that some vibrations or other uncertain factors may cause the measuring chamber to tilt or cause the load-bearing plate to tilt together, which will cause errors in the entire measurement results. Utility Model Content

[0006] The purpose of the utility model is to provide an automated trace meter to solve the problem in the prior art that, during the measurement process, if the measuring chamber cannot maintain vertical pressure transmission, the measurement result will be affected.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] An automated trace meter comprises a bottom shell, in which a pressure sensor is installed, a measuring chamber is installed on the upper side of the bottom shell above the pressure sensor, a windshield for covering the measuring chamber is provided on the upper side of the bottom shell, a light source is installed on the side of the windshield, a photosensor is installed on the inner top of the windshield, the sensing surface of the photosensor is arranged facing downward, and a light shield is installed on the lower side of the photosensor, a first light hole is provided on the light shield that passes through from top to bottom, and a reflector for reflecting light emitted by the light source into the first light hole is installed on the upper side of the measuring chamber.

[0009] A further technical solution is that a mounting hole that passes through the inner and outer sides is provided on the side of the windshield, and the light source is installed in the mounting hole.

[0010] A further technical solution is that a focusing plate is installed in the installation hole, the focusing plate is installed between the light source and the reflector, and a second light hole is provided on the focusing plate that passes through both ends.

[0011] A further technical solution is that a fixing ring for mounting the wind shield is provided on the upper side of the bottom shell.

[0012] A further technical solution is that a fixed enclosure is vertically arranged around the edge of the fixed ring, the outer wall of the wind shield is installed to fit the inner wall of the fixed enclosure, a first positioning hole is provided on the fixed enclosure that passes through both sides, and a second positioning hole matching the first positioning hole is provided on the outer wall of the wind shield. When the first positioning hole and the second positioning hole are aligned, they are fixed by positioning pins.

[0013] Compared with the prior art, the present invention has the following beneficial effects: 1. When the measuring chamber is not tilted, the light emitted by the light source is reflected by the reflector and can be irradiated onto the photosensor through the first light hole. When the measuring chamber is tilted, the reflector will tilt along with it, which will cause the angle and direction of reflection to change, so that the light generated by the light source cannot be irradiated onto the photosensor through the first light hole after reflection. In this way, whether the measuring chamber maintains vertical pressure transmission can be judged based on whether the photosensor detects the light signal, thereby improving the measurement accuracy; 2. By setting the first light hole, the light receiving surface of the light surface sensor can be controlled, thereby improving the detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is an overall schematic diagram of an automated trace instrument of the present utility model.

[0015] Figure 2 This is a partial cross-sectional view of an automated tracer according to the present invention.

[0016] Figure 3 This is a temperature acquisition circuit diagram of an automatic trace instrument of the utility model.

[0017] Figure 4 The utility model is a weighing circuit diagram of an automatic trace meter.

[0018] Figure 5 for Figure 2 A partial enlarged schematic diagram of the area marked A.

[0019] Icons: 1-measuring chamber; 2-temperature sensor; 3-pressure sensor; 4-controller; 5-measuring hole; 6-flexible thermal conductive film; 7-anti-steaming screen; 8-through hole; 9-bottom shell; 10-windproof cover; 11-drip hole; 12-protective plate; 13-passage hole; 14-weighing plate; 15-positioning slot; 16-pipette head; 17-host computer; 18-analog-to-digital converter; 19-microcontroller unit; 20-external interface; 21-power module; 22-light source; 23-photosensitive sensor; 24-light shield; 25-first light hole; 26-reflector; 27-mounting hole; 28-condensing plate; 29-second light hole; 30-fixing ring; 31-fixing enclosure; 32-first positioning hole; 33-second positioning hole; 34-positioning pin DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0021] Figures 1 to 5 This is an embodiment of the present utility model.

[0022] Example 1:

[0023] An automated tracer, referring to Figure 1 、 Figure 2 , including a measuring chamber 1, a temperature sensor 2, a pressure sensor 3 and a controller 4. The measuring chamber 1 is opened at the top, the temperature sensor 2 is arranged at the bottom of the measuring chamber 1, and the pressure sensor 3 is arranged below the measuring chamber 1. The temperature sensor 2 and the pressure sensor 3 are both electrically connected to the controller 4. The temperature sensor 2 is used to measure the temperature of the liquid inside the measuring chamber 1, and the pressure sensor 3 is used to measure the weight of the liquid inside the measuring chamber 1. Multiple pipetting is performed in the measuring chamber through a single channel, and the temperature, mass and volume of each pipetting are measured and calculated at the same time. The single-channel pipetting consistency is calculated by the controller 4, and the metering accuracy of the single channel is judged. The smaller the single-channel pipetting consistency value, the higher the pipetting metering accuracy of the single channel. Conversely, the lower the pipetting metering accuracy of the single channel, the total standard deviation of the high-throughput pipetting can also be calculated, which is convenient for judging and calibrating the overall pipetting accuracy of the high-throughput pipetting equipment. The smaller the total standard deviation, the higher the overall pipetting accuracy of the high-throughput pipetting equipment.

[0024] Reference Figure 1 、 Figure 2The inner bottom wall of the measuring chamber 1 is provided with an inclined lowest point, and the inner bottom wall of the measuring chamber 1 is a concave cone, and the inclined lowest point is located directly below the center of gravity of the measuring chamber 1. A through measuring hole 5 is opened at the inclined lowest point of the bottom wall of the measuring chamber 1, and the side of the measuring hole 5 close to the interior of the measuring chamber 1 is covered with a flexible thermal conductive film 6. The sensing end of the temperature sensor 2 is placed in the measuring hole 5 and is tightly pressed against the lower surface of the flexible thermal conductive film 6 (the side of the flexible thermal conductive film 6 facing away from the interior of the measuring chamber 1). After adding liquid to the measuring chamber 1, the liquid gathers at the lowest point inside the measuring chamber 1, which is conducive to maintaining the balance and stability of the measuring chamber 1; the temperature sensor 2 adopts a thermistor temperature sensor 2, and the sensing part of the temperature sensor 2 measures the liquid in the measuring chamber 1 through the flexible thermal conductive film 6, with sensitive response and good stability.

[0025] Reference Figure 1 、 Figure 2 A detachable cover above the measuring chamber 1 is provided with an anti-steam screen 7. The anti-steam screen 7 and the measuring chamber 1 are both made of ultra-light and low thermal conductivity materials. The ultra-light and low thermal conductivity materials can be aerogel materials, vacuum insulation materials, graphite polystyrene materials and PFT insulation materials, etc. A through hole 8 for the pipetting head 16 to pass through is opened on the anti-steam screen 7. The operating pipetting head 16 extends through the through hole 8 of the anti-steam screen 7 into the measuring chamber 1 to add liquid. The anti-steam screen 7 is beneficial to reducing the evaporation and loss of liquid in the measuring chamber 1, which is especially important for the precision measurement of ultra-micro pipetting.

[0026] Reference Figure 1 、 Figure 2 The trace meter also includes a bottom shell 9 arranged below the measuring chamber 1, and the pressure sensor 3 is arranged in the bottom shell 9. A windshield 10 is provided on the bottom shell 9 through a snap fastener, which is convenient for disassembling the windshield 10. The windshield 10 is used to cover the measuring chamber 1. A drip hole 11 for the pipette head 16 to pass through is provided on the top wall of the windshield 10. There is a gap between the measuring chamber 1 and the anti-steam screen 7 and the windshield 10 respectively. The windshield 10 is conducive to reducing the shaking effect of the flow of external air on the measuring chamber 1, which is conducive to ensuring the accuracy of the liquid weight measurement of the measuring chamber 1. The outer top wall of the windshield 10 is also provided with a protective plate 12 through a snap fastener. The protective plate 12 is used in conjunction with the anti-steam screen 7. A through hole 13 is provided on the protective plate 12 for the pipetting head 16 to pass through. The center lines of the through hole 13, the dripping hole 11, the through hole 8 and the measuring hole 5 are all vertically arranged and coincide with each other. The aperture of the through hole 13 is smaller than the aperture of the through hole 8, and the aperture of the through hole 13 is smaller than the aperture of the dripping hole 11, so as to prevent the pipetting head 16 from touching the anti-steam screen 7 and the windshield 10 after extending into the measuring chamber 1, and facilitate the pipetting head 16 to pass through the through hole 13, the dripping hole 11 and the through hole 8 in turn and directly drop the liquid on the measuring hole 5 of the measuring chamber 1, which is beneficial to maintaining the balance and stability of the measuring chamber 1 and to ensuring the accuracy of the liquid weight data measured by the pressure sensor 3.

[0027] Reference Figure 1 、 Figure 2 A weighing pan 14 is provided below the measuring chamber 1, and the pressure sensor 3 is provided in the middle position just below the weighing pan 14. A positioning groove 15 is provided on the upper surface of the weighing pan 14. The positioning groove 15 is concave inwardly conical. The positioning groove 15 includes a horizontally arranged inner bottom wall and a concave conical surface. A positioning portion is provided on the outer bottom wall of the measuring chamber 1. The positioning portion is a convex conical structure, and the positioning portion matches the shape of the positioning groove 15 (that is, the positioning portion includes a convex conical surface and a horizontal bottom surface located below the conical surface). The positioning portion is located in the positioning groove 15, and the positioning portion is used to align the measuring chamber 1 with the measuring chamber 1. The measuring bin 1 is positioned on the weighing pan 14, which makes it easy to quickly and accurately place the measuring bin 1 at the designated position on the weighing pan 14 and ensure the balance of the measuring bin 1; the measuring hole 5 is located at the horizontal bottom surface of the positioning portion, that is, the measuring hole 5 is located directly above the horizontal inner bottom wall of the positioning groove 15. At this time, the sensing end of the temperature sensor 2 is located at the inner bottom wall of the positioning groove 15, so that the center of gravity of the measuring bin 1 is located directly above the inner bottom wall of the positioning groove 15, which is conducive to keeping the balance and stability of the measuring bin 1 at all times while adding liquid into the measuring bin 1.

[0028] Reference Figure 1 、 Figure 2 Two analog-to-digital converters 18 (ADCs), a microcontroller unit 19 (MCU), and a power module 21 are provided within the housing. One ADC 18 is electrically connected to the temperature sensor 2 via a temperature acquisition circuit, and the other is electrically connected to the pressure sensor 3 via a weighing circuit. Both ADCs 18 are electrically connected to the MCU 19. The MCU 19 reads the temperature data measured by the temperature sensor 2 and the liquid weight data measured by the pressure sensor 3 via the corresponding ADC 18. The housing is also provided with an external interface 20. The controller 4 transmits power to the external interface 20 via a cable. The power module 21 obtains input power from the external interface 20 and modulates the power into a reference power supply AVDD, a highly stable differential power supply VCC+ and VCC-, and the like. After the system is started, the controller 4 transmits a 5V voltage to the external interface 20 via a connecting cable. The power module 21 adjusts and stabilizes the voltage and then supplies power to other modules. After the MCU 19 is powered on, it initializes the peripherals and performs a system self-test. After the self-test is completed, the system enters the startup state.

[0029] Reference Figure 2 、 Figure 3The temperature acquisition circuit includes a thermistor NTC, a first resistor R1, a second resistor R2 and a capacitor C4. R2, R1 and C4 are connected in series in sequence. The end of R2 away from R1 is connected to the reference power supply AVDD, and the end of C4 away from R1 is grounded. The NTC is connected to the analog-to-digital converter 18 and then connected in parallel with R1. The reference power supply AVDD is divided by R2 and acts on the NTC. The high-voltage side of the NTC is connected to the analog-to-digital converter 18 through R1 to realize signal acquisition and AD conversion. The analog-to-digital converter 18 then transmits the temperature data to the microcontroller unit 19.

[0030] Reference Figure 1 、 Figure 2 、 Figure 4 The weighing circuit includes a third resistor R3, a fourth resistor R4, an operational amplifier U2, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7 and an eighth resistor R8, R3 and R8 are variable resistors, U2 is an operational amplifier, referred to as an operational amplifier, the operational amplifier U2, the fifth resistor R5, the sixth resistor R6, and the seventh resistor R7 together constitute a current-voltage conversion amplifier circuit, R5 is connected in parallel between the in-phase input terminal and the output terminal of U2, and the negative input terminal of U2 is grounded; the current balancer U1 of the pressure sensor 3 is connected to the weighing circuit, one end of U1 is connected in series with the fourth resistor R4 and the sliding resistor R3 in sequence, the high-stable differential power supply VCC+ and VCC- provide a set of high-stable differential power supplies of equal size and opposite phase to the weighing circuit, and R3 is far away from R4. One end is connected to VCC+, the end of U1 away from R4 is electrically connected to the non-inverting input of U2, and the inverting input of U2 is connected in series with R6, R7, and R8. The end of R8 away from R7 is connected to VCC-. One end of the analog-to-digital converter 18 is electrically connected to the output of U2, and the other end is connected to the circuit between R6 and R7. By adjusting the variable resistors R3 and R8, the current balancer can reach initial equilibrium. When the measured liquid is added to the measuring chamber 1, the pressure sensor 3 is subjected to force, and the current balancer U1 outputs a microcurrent. The current-to-voltage conversion and amplification circuit converts the microcurrent output of the current balancer U1 into a voltage signal and amplifies it. The analog-to-digital converter 18 performs analog-to-digital conversion on the converted and amplified voltage signal and outputs the liquid weight data to the microcontroller 19. After the pipette head 16 adds the liquid to the measuring chamber 1, the microcontroller 19 transmits the measured data via the data bus to the controller 4. The controller 4 calculates and corrects the data and uploads all the data to the host computer 17 for recording and storage.

[0031] Example 2:

[0032] On the basis of Example 1, an automated trace meter includes a bottom shell 9, a pressure sensor 3 is installed in the bottom shell 9, a measuring chamber 1 is installed on the upper side of the pressure sensor 3 on the upper side of the bottom shell 9, and a windshield 10 for covering the measuring chamber 1 is provided on the upper side of the bottom shell 9, characterized in that a light source 22 is installed on the side of the windshield 10, a photosensor 23 is installed on the inner top of the windshield 10, the sensing surface of the photosensor 23 is arranged facing downward, and a light shielding plate 24 is installed on the lower side of the photosensor 23, a first light hole 25 which passes through from top to bottom is provided on the light shielding plate 24, and a reflector 26 for reflecting light emitted by the light source 22 into the first light hole 25 is installed on the upper side of the measuring chamber 1. When the measuring chamber 1 is not tilted, the light emitted by the light source 22 is reflected by the reflector 26 and can illuminate the photosensor 23 through the first light hole 25. However, when the measuring chamber 1 is tilted, the reflector 26 will tilt along with it, which will cause the angle and direction of reflection to change. As a result, the light generated by the light source 22 cannot illuminate the photosensor 23 through the first light hole 25 after reflection. In this way, it is possible to determine whether the measuring chamber 1 maintains vertical pressure transmission based on whether the photosensor 23 detects a light signal, thereby improving the measurement accuracy. By setting the first light hole 25, the light receiving surface of the light surface sensor can be controlled, thereby improving the detection accuracy. The reflector 26 adopts a 45-degree reflection, and the first light hole is vertically aligned with the reflector 26. In this way, the reflection of the light will only be affected when the measuring chamber 1 is tilted, so that the light cannot accurately enter the first light hole 25. The vertical movement of the measuring chamber 1 will not affect the reflection of the light. In order to avoid the center of gravity shifting due to the installation of the reflector 26 on the measuring chamber 1, the reflector 26 is installed symmetrically to balance the position of the center of gravity.

[0033] The side of the windshield 10 is provided with a mounting hole 27 that passes through both the inside and outside, and the light source 22 is installed in the mounting hole 27. The mounting hole 27 facilitates the fixing of the light source 22. The light source 22 can be well fixed on the windshield 10 and connected to the windshield 10 as a whole, and the position between the light source 22 and the light sensor 23 can be easily controlled, so that the reflector 26 can accurately reflect.

[0034] A focusing plate 28 is also mounted within the mounting hole 27. This focusing plate 28 is mounted between the light source 22 and the reflector 26. A second light hole 29 is provided on the focusing plate 28, extending through both ends. The provision of the focusing plate 28 and the second light hole 29 controls the diameter of the emitted light, preventing diffuse reflection of the divergent light within the windshield 10 from affecting the detection effect of the photosensor 23.

[0035] A fixing ring 30 for mounting the wind shield 10 is provided on the upper side of the bottom shell 9. By providing the fixing ring 30, the position of the wind shield 10 can be easily controlled.

[0036] A fixed enclosure 31 is vertically arranged around the edge of the fixing ring 30. The outer wall of the wind shield 10 is mounted on the inner wall of the fixed enclosure 31. A first positioning hole 32 is provided on the fixed enclosure 31, which passes through both sides. A second positioning hole 33 is provided on the outer wall of the wind shield 10 to match the first positioning hole 32. When the first positioning hole 32 and the second positioning hole 33 are aligned, they are fixed by a positioning pin 34. By providing the first positioning hole 32, the second positioning hole 33 and the positioning pin 34, the wind shield 10 can be accurately fixed. In this way, after the wind shield is fixed, the light source 22 can be accurately aligned with the reflector 26, avoiding the impact of errors caused by the installation of the wind shield 10 on the detection effect.

[0037] Although the present invention has been described herein with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and implementations may be devised by those skilled in the art that fall within the scope and spirit of the principles disclosed herein. More specifically, within the scope of the present disclosure, the drawings, and the claims, various variations and modifications may be made to the components and / or layout of the subject combination arrangement. In addition to variations and modifications to the components and / or layout, other uses will also be apparent to those skilled in the art.

Claims

1. An automated trace meter, comprising a bottom shell (9), a pressure sensor (3) installed in the bottom shell (9), a measuring chamber (1) installed on the upper side of the pressure sensor (3) on the upper side of the bottom shell (9), and a windshield (10) for covering the measuring chamber (1) provided on the upper side of the bottom shell (9), characterized in that: A light source (22) is installed on the side of the wind shield (10), a photosensor (23) is installed on the inner top of the wind shield (10), the sensing surface of the photosensor (23) is arranged downward, and a light shielding plate (24) is installed on the lower side of the photosensor (23), a first light hole (25) that passes through the light shielding plate (24) is provided, and a reflector (26) for reflecting light emitted by the light source (22) into the first light hole (25) is installed on the upper side of the measuring chamber (1).

2. An automated tracer according to claim 1, characterized in that: A mounting hole (27) is provided on the side of the wind shield (10) and passes through the inner and outer sides, and the light source (22) is mounted in the mounting hole (27).

3. An automated tracer according to claim 2, characterized in that: A light collecting plate (28) is also installed in the installation hole (27). The light collecting plate (28) is installed between the light source (22) and the reflector (26). A second light-through hole (29) is provided on the light collecting plate (28) that passes through both ends.

4. An automated tracer according to claim 1, characterized in that: A fixing ring (30) for mounting the wind shield (10) is provided on the upper side of the bottom shell (9).

5. An automated tracer according to claim 4, characterized in that: A fixed enclosure (31) is vertically arranged around the edge of the fixed ring (30), the outer wall of the mounting wind shield (10) is fitted to the inner wall of the fixed enclosure (31), a first positioning hole (32) passing through both sides is provided on the fixed enclosure (31), and a second positioning hole (33) matching the first positioning hole (32) is provided on the outer wall of the wind shield (10), and when the first positioning hole (32) and the second positioning hole (33) are aligned, they are fixed by a positioning pin (34).

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