CN101865718B - Liquid level detection circuit, device and calibration method thereof - Google Patents
Liquid level detection circuit, device and calibration method thereof Download PDFInfo
- Publication number
- CN101865718B CN101865718B CN 200910106680 CN200910106680A CN101865718B CN 101865718 B CN101865718 B CN 101865718B CN 200910106680 CN200910106680 CN 200910106680 CN 200910106680 A CN200910106680 A CN 200910106680A CN 101865718 B CN101865718 B CN 101865718B
- Authority
- CN
- China
- Prior art keywords
- liquid level
- variable resistor
- voltage
- control
- sampling needle
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Measurement Of Levels Of Liquids Or Fluent Solid Materials (AREA)
- Measurement Of Resistance Or Impedance (AREA)
Abstract
The invention discloses a liquid level detection circuit, a device and a calibration method thereof. The liquid level detection circuit comprises a voltage controlled oscillator, a phase discriminator, a judgment unit and a variable resistor unit, wherein the voltage controlled oscillator is respectively connected with two output terminals of a sampling needle and the variable resistor unit, and outputs a first signal to the phase discriminator, the phase discriminator receives the first signal and a reference signal, and respectively outputs control voltage relevant to the frequency difference value of the first signal and the reference signal to the voltage controlled oscillator and the judgment unit, the judgment unit outputs a control signal to the variable resistor unit according to the control voltage in the calibration state, and the variable resistor unit sets the self resistance value according to the control signal. The invention compensates the capacitance through regulating the resistance value of an oscillator resistor, and realizes the self calibration of the liquid level defection device, and the replacement of the sampling needle by customers is easier.
Description
[technical field]
The present invention relates to a kind of sample adding system, relate in particular to the liquid level sensor in the sample adding system.
[background technology]
In medical field, often need realize detecting sampling and the application of sample of sample and/or reactant liquor with sample adding system.In the liquid sample adding system (as the Biochemical Analyzer sample adding system) based on sampling needle, liquid level detection circuit often utilizes sampling needle equivalent capacity variation detection principle whether sampling needle contact liquid level is judged.Sampling needle in process of production, there is certain tolerance in its electric capacity, this tolerance has considerable influence to the performance of liquid level detection circuit.Therefore, liquid level detection circuit need be calibrated at concrete sampling needle usually.
At present, at concrete sampling needle carry out Calibration Method be by and the method that connects electric capacity the tolerance of sampling needle electric capacity is compensated.As shown in Figure 1, liquid level detection circuit comprises capacitive detection circuit 23, signal condition unit 24 and control module 25.The simulating signal of the reflection capacitance of capacitive detection circuit 23 outputs is sent into control module 25 behind signal condition unit 24, judge whether sampling needle contacts liquid level.Electric capacity 22 is the equivalent capacity of sampling needle, and there is certain tolerance in electric capacity 22 initial values, and this tolerance has certain influence to detecting performance.At present, by the trimmer 21 in parallel at the two ends of electric capacity 22, the manufacturing tolerance of electric capacity 22 is compensated, optimize the purpose that detects performance to reach.But this calibration steps is comparatively loaded down with trivial details and be not easy to regulate on technology, and is particularly more difficult when the client need change sampling needle voluntarily.
[summary of the invention]
The main technical problem to be solved in the present invention is, a kind of liquid level detection circuit, device and calibration steps thereof are provided, and can carry out self calibration at different sampling needles.
According to an aspect of the present invention, provide a kind of liquid level detection circuit, comprising: voltage controlled oscillator, phase detector, judging unit and variable resistor unit; Described voltage controlled oscillator be used for to connect two lead-out terminals of sampling needle, and output frequency first signal relevant with the cycle that discharges and recharges of described sampling needle equivalent capacity is to phase detector; Described phase detector receives first signal and reference signal, and exports the control voltage relevant with the frequency-splitting of first signal and reference signal respectively to described voltage controlled oscillator and judging unit; Described judging unit judges according to control voltage whether sampling needle touches liquid level; Described judging unit also is used for outputing control signals to described variable resistor unit according to described control voltage when align mode, described variable resistor unit is according to the resistance value of control signal setting self, and described voltage controlled oscillator also connects the two ends of variable resistor unit and makes described variable resistor unit insert the charging and discharging circuit of described equivalent capacity.
According to a further aspect in the invention, also provide a kind of liquid level sensor, comprise sampling needle and above-mentioned liquid level detection circuit.
According to a further aspect in the invention, also provide a kind of calibration steps of above-mentioned liquid level sensor, comprising:
Make sampling needle be in predetermined state to be calibrated;
Select the target voltage values corresponding with this state to be calibrated;
Control voltage and target voltage values that actual acquisition is arrived compare;
Regulate the resistance value of himself according to comparative result control variable resistor unit.
The present invention has realized the compensation to the sampling needle equivalent capacity, thereby has realized the self calibration of liquid level sensor by the adjusting to oscillator resistor.According to calibration steps of the present invention, avoided the manual adjustment of carrying out at concrete sampling needle, be more prone in the time of can making the client change sampling needle voluntarily, and can carry out self-adaptation under different working environments regulates, can eliminate environment to the influence of the equivalent capacity of liquid level sensor detection, make the detection system property retention at kilter.
[description of drawings]
Fig. 1 is a kind of functional-block diagram of liquid level sensor;
Fig. 2 is the liquid level sensor functional-block diagram of an embodiment of the present invention;
Fig. 3 is the calibration process flow diagram of an embodiment of the present invention.
[embodiment]
By reference to the accompanying drawings the present invention is described in further detail below by embodiment.
Please refer to Fig. 2, liquid level sensor comprises sampling needle and liquid level detection circuit, and wherein, liquid level detection circuit comprises variable resistor unit 2, voltage controlled oscillator 3, phase detector 5 and judging unit 100.Sampling needle adopts the structure of two thimble tubes usually, produces capacity effect between the internal and external casing, can equivalence become an electric capacity.Equivalent capacity 1 is the equivalent capacity of sampling needle.Equivalent capacity 1 is connected voltage controlled oscillator 3 respectively with variable resistor unit 2, is linked in the circuit of voltage controlled oscillator 3, and equivalent capacity 1 is as the charge and discharge capacitance of voltage controlled oscillator 3.Variable resistor unit 2 is as the oscillator resistor of voltage controlled oscillator 3, and conduct discharges and recharges resistance in the charging and discharging circuit of access electric capacity 1.Voltage controlled oscillator 3 is used for control equivalent capacity 1 and discharges and recharges, and it is relevant with the cycle that discharges and recharges of equivalent capacity 1 to the frequency of phase detector 5, the first signals 4 to export first signal 4.Under the constant situation of resistance 2 resistances, the frequency of first signal 4 of voltage controlled oscillator 3 outputs will change along with equivalent capacity 1.Described phase detector 5 receives first signal 4 and reference signal 7, first signal 4 and reference signal 7 are carried out frequency ratio, and phase detector 5 is controlled voltage 6 and is applied to voltage controlled oscillator 3 and judging unit 100 respectively according to the corresponding control of the output of the frequency-splitting between first signal 4 and the reference signal 7 voltage 6.Voltage controlled oscillator 3 is controlled the frequency that discharges and recharges of equivalent capacity 1 according to controlling voltage 6, makes the frequency of first signal 4 of output tend to consistent with the frequency of reference signal 7.Judging unit 100 judges according to control voltage 6 whether sampling needle touches liquid level.
Parts such as voltage controlled oscillator 3, phase detector 5, equivalent capacity 1, variable resistor unit 2 have constituted a complete phaselocked loop 8, and the output of this phaselocked loop 8 that is control voltage 6 have reflected the value of equivalent capacity 1.
Sampling needle is in manufacturing process, and its electric capacity is limited by processing technology, has certain tolerance, and this tolerance makes the initial value of control voltage 6 there are differences, and this performance to testing circuit has considerable influence.For system is worked better, must manage this tolerance is compensated, make behind the different sampling needle places in circuit that contact or do not contact under liquid level or other object conditions equal, the control voltage 6 of phaselocked loop 8 outputs remains on the level of basically identical.Have certain difficulty owing to directly equivalent capacity 1 is compensated, therefore in the present embodiment, adopt the mode that oscillator resistor is compensated, in the present embodiment, oscillator resistor can power transformation resistance unit 2.
Therefore, judging unit 100 is also exported control signal 12 to described variable resistor unit 2, and the resistance value of self is set in described variable resistor unit 2 according to control signal 12.The ultimate principle of compensation can be illustrated by the formula of reduction of phaselocked loop 8:
In the formula, f is the frequency of the signal of voltage controlled oscillator output, f equals the frequency (fixed value) of reference signal 7 under the condition of phaselocked loop locking, u is the magnitude of voltage of control voltage 6, R is oscillator resistor, can power transformation hinder the resistance value that unit 2 is set, C is the capacitance of equivalent capacity 1, and K is phaselocked loop constant (fixed value).Because there is tolerance in the initial capacitance C of different sampling needles, cause the initial value of corresponding u there are differences; In the present embodiment, by regulating R, get final product the resistance of power transformation resistance unit 2, make different sampling needles can both obtain identical u.After self calibration, detect in the process of liquid level, f, K, R are definite value, this moment, u and C were directly proportional, but namely controlled the variation of the variation quantitative response equivalent capacity 1 of voltage 6.
In the present embodiment, as shown in Figure 2, judging unit 100 comprises modulate circuit 9 and control module, control module comprises Acquisition Circuit 10 and controller 11 again, described modulate circuit 9 links to each other with the output terminal of described phase detector 5, be used for receiving described control voltage 6, and the control voltage after the output processing is to Acquisition Circuit 10, Acquisition Circuit 10 is used for the control voltage after the processing of described modulate circuit 9 outputs is sampled, and sampled result outputed to controller 11, described controller 11 is used for sampled result and setting threshold (for example voltage threshold or change in voltage slope threshold value) are compared, and whether touches liquid level to judge sampling needle.When liquid level sensor was in align mode, control voltage and predetermined target voltage value that described controller 11 is gathered Acquisition Circuit 10 compared, according to comparative result to the variable resistor unit 2 output control signals.The resistance of self is regulated according to the control signal that receives in variable resistor unit 2, thereby regulates the control voltage of output.
In the present embodiment, variable resistor unit 2 comprises digital regulation resistance, and the two ends of digital regulation resistance connect two terminals of described voltage controlled oscillator 3 respectively, and control end is coupled to described controller 11.Digital regulation resistance is a kind of programme controlled adjustable element of being convenient to, and its resistance to self under the control of controller 11 is regulated.
Present embodiment utilizes principle of phase lock loop, will originally the compensation of electric capacity be converted into the compensation to resistance of easier realization on the engineering, and uses digital regulation resistance element by way of compensation, in conjunction with control software and sequential design, has realized the automatic adjustment of testing circuit.Present embodiment has been exempted the manual adjustment of carrying out at concrete sampling needle, is more prone to when making the client change sampling needle voluntarily.And can carry out self-adaptation under different working environments automatically regulates, by setting the resistance that mates with current environment, also can eliminate environment (for example temperature, humidity) to the influence of the equivalent capacity of liquid level sensor detection, make the detection system performance remain at kilter.
In above-described embodiment, Acquisition Circuit 10 is replaceable to be comparer, this moment, controller 11 only knew that from comparer current control voltage 6 is higher than or is lower than desired value, and exported control signal accordingly, and oscillator resistor (can power transformation resistance unit 2) is regulated step by step.Be adjusted to comparer always and overturn (illustrating that control voltage 6 is near desired value), adjustment can finish.In case of necessity, also can regulate direction readjustment one-level to certain, (for example guarantee repeatedly adjustment result's consistance, regulation is adjusted to the comparer upset from the top down and the time must adjusts back one-level, not adjust back when being adjusted to the comparer upset from bottom to top, can so that the result of each adjustment always remain on target voltage above and with target voltage gap minimum).
In above-described embodiment, variable resistor unit 2 also can be realized by the different resistance that analog multichannel switch and each road connect except adopting the digital regulation resistance realization, also can realize by a plurality of parallel control loops that are in series with different resistance.
The self-alignment flow process of liquid level sensor may further comprise the steps as shown in Figure 3:
In step S101, make sampling needle be in predetermined state to be calibrated, its effect is to by the fair consistent external capacitive environment (this environment electric capacity and sampling needle capacitive junctions have constituted equivalent capacity 1 altogether) of one of the different sampling needle of adjustment.Predetermined state to be calibrated comprises any in the following state:
A. sampling needle is in the state that does not contact or keep clear of liquid level and other object, and in biochemical instruments, sampling needle moves to the service sink top;
B. sampling needle be in the predetermined container and contacting container in the state of liquid of predetermined quantity and predefined type, in biochemical instruments, sampling needle inserts to be had in the service sink of certain water yield;
C. sampling needle is in the state of contact or close predetermined object, and in biochemical instruments, sampling needle inserts in the reaction tray of metal material.
Behind the completing steps S101, execution in step S103.
In step S103, select the target voltage values corresponding with the residing state to be calibrated of sampling needle.
The control voltage 6 of phaselocked loop 8 outputs is sent into modulate circuit 9 and is carried out signal condition, and modulate circuit 9 generally comprises follower, low-pass filter and amplifier, differentiator or block isolating circuit can also be arranged in case of necessity to extract change amount signal.Signal after the conditioning enters Acquisition Circuit 10 and carries out analog to digital conversion, delivers to controller 11 then and analyzes.At system design stage, pre-determine the target voltage values of the control voltage 6 corresponding with the sampling needle state to be calibrated selected among the step S101, capacitance change or voltage variety are relevant before and after target voltage values and phaselocked loop supply voltage, the contact liquid level.The foundation of determining target voltage values is: one period before and after the contact liquid level, near variation phaselocked loop 8 output voltage range intermediate values of control voltage 6.For example for the phaselocked loop 8 of 9V power supply, adopt when calibrating under state A to be calibrated (namely not contacting or keeping clear of liquid level and other object) pattern, the intermediate value of phaselocked loop 8 output voltage ranges is 4.5V, one period before and after the contact liquid level, the about 2V of voltage variety, adopt state A pattern to be calibrated, target voltage values is got 3.5V, before then contacting liquid level, control voltage 6 is 3.5V, behind the contact liquid level, control voltage 6 changes 2V and reaches 5.5V, near this constant interval (3.5V～5.5V) drop on just the intermediate value 4.5V.Therefore target voltage values can be taken as 3.5～4.5V as required.Execution in step S105 then.
In step S105, control voltage and target voltage values that actual acquisition is arrived compare.Real-time collection result and this target voltage values that controller 11 will be controlled voltage 6 compare, then execution in step S107.
In step S107, regulate the resistance value of himself according to comparative result control variable resistor unit.If control voltage is lower than target voltage values, then controls the variable resistor unit and increase the resistance value of himself; If control voltage is higher than target voltage values, then controls the variable resistor unit and reduce the resistance value of himself.Be the situation of digital regulation resistance for the variable resistor unit, increase or the amount that reduces can be made as 1 digital regulation resistance step simply at every turn, also can adopt more complicated algorithm such as FUZZY ALGORITHMS FOR CONTROL to realize more high efficiency adjusting.It is stable to treat phaselocked loop 8 generally need to make suitable time-delay after the adjusting, and when for example regulating 1 digital regulation resistance step, time-delay needs 1ms approximately at every turn.Execution in step S109 then.
In step S109, judge whether the collection result of control voltage 6 and the difference of this target voltage values satisfy predetermined condition, if satisfy, then finish, if do not satisfy, then turn to step S105, repeated execution of steps S105 and S107, resistance value after this moment, the variable resistor unit sampling was regulated, control voltage 6 also be with regulate after the resistance corresponding voltage value.Described predetermined condition comprises any in the following condition:
A. the deviation of controlling voltage and target voltage values is little in predetermined scope;
B. the deviation of controlling voltage and target voltage values reaches minimum value and this value in predetermined scope;
C. do not satisfy condition a and b, but the variable resistor unit has been adjusted to the limit, comprises the limit or the predetermined limit value of software of device.Not success of adjustment is described this moment, can takes the circumstances into consideration to carry out retry or report an error.
In the above-mentioned flow process, if selecting state A pattern to be calibrated in the step 101 calibrates under the state that does not contact or keep clear of liquid level and other object, then calibration process is not limited to when sampling needle is static and carries out, also can in the sampling needle motion process, carry out, this moment is owing to parts are moving, human body is avoided by the light of nature, avoided better touching sampling needle and influence calibration.
Above-mentioned calibration process both can manual triggers, also can automatically perform, and general the employing automatically performs, to reach the purpose of simplifying testing and measuring technology.Concrete mode of operation can comprise following any:
1, power at every turn or reset after carry out primary calibration;
2, in the course of work, utilize idle period to calibrate frequently;
3, go through once or calibration for several times after, parameter is kept in oscillator resistor 2 or the controller 11, no longer calibrate later on, but directly be written into this value.
Behind each replacing sampling needle, can calibrate.
In sum, the present invention proposes a kind of liquid level detection circuit structure, utilize principle of phase lock loop will be converted into the compensation to resistance of easier realization on the engineering originally to the compensation of electric capacity, in conjunction with control software and sequential design, realized the self calibration of liquid level sensor.The present invention has exempted the manual adjustment of carrying out at concrete sampling needle, is more prone to when making the client change sampling needle voluntarily, and can carries out self-adaptation automatically and regulate under different working environments, makes the detection system property retention at kilter.
Above content be in conjunction with concrete embodiment to further describing that the present invention does, can not assert that concrete enforcement of the present invention is confined to these explanations.For the general technical staff of the technical field of the invention, without departing from the inventive concept of the premise, can also make some simple deduction or replace, all should be considered as belonging to protection scope of the present invention.
Claims (14)
1. a liquid level detection circuit is characterized in that comprising: voltage controlled oscillator, phase detector, judging unit and variable resistor unit; Described voltage controlled oscillator be used for to connect two lead-out terminals of sampling needle, and output frequency first signal relevant with the cycle that discharges and recharges of described sampling needle equivalent capacity is to phase detector; Described phase detector receives first signal and reference signal, and exports the control voltage relevant with the frequency-splitting of first signal and reference signal respectively to described voltage controlled oscillator and judging unit; Described judging unit judges according to control voltage whether sampling needle touches liquid level; Described judging unit also is used for outputing control signals to described variable resistor unit according to described control voltage when align mode, described variable resistor unit is according to the resistance value of control signal setting self, and described voltage controlled oscillator also connects the two ends of variable resistor unit and makes described variable resistor unit insert the charging and discharging circuit of described equivalent capacity.
2. liquid level detection circuit as claimed in claim 1, it is characterized in that, described judging unit comprises modulate circuit and control module, described modulate circuit links to each other with the output terminal of described phase detector, be used for receiving described control voltage, and the control voltage of output after handling is to control module, and described control module judges according to the control voltage after handling whether sampling needle touches liquid level, and described control module also outputs control signals to described variable resistor unit.
3. liquid level detection circuit as claimed in claim 2 is characterized in that, described variable resistor unit comprises digital regulation resistance, and the two ends of described digital regulation resistance connect two terminals of described voltage controlled oscillator respectively, and control end is coupled to described control module.
4. as claim 2 or 3 described liquid level detection circuits, it is characterized in that, described control module comprises Acquisition Circuit and controller, described Acquisition Circuit is used for the control voltage after the processing of described modulate circuit output is sampled, and sampled result outputed to controller, described controller is used for sampled result and setting threshold are compared, to judge whether sampling needle touches liquid level, described controller also is used for when align mode described sampled result and predetermined target voltage value being compared, and exports described control signal according to comparative result.
5. as claim 2 or 3 described liquid level detection circuits, it is characterized in that, described control module comprises comparator circuit and controller, described comparator circuit is used for control voltage and setting voltage threshold value after the processing of described modulate circuit output are compared, and comparative result outputed to controller, described controller is used for exporting described control signal according to comparative result.
6. a liquid level sensor is characterized in that comprising: each described liquid level detection circuit in sampling needle and the claim 1 to 5.
7. the calibration steps of liquid level sensor as claimed in claim 6 is characterized in that comprising:
Make sampling needle be in predetermined state to be calibrated;
Select the target voltage values corresponding with this state to be calibrated;
Control voltage and target voltage values that actual acquisition is arrived compare;
Regulate the resistance value of himself according to comparative result control variable resistor unit.
8. calibration steps as claimed in claim 7 is characterized in that, described predetermined state to be calibrated comprises any in the following state:
Sampling needle is in the state that does not contact or keep clear of liquid level and other object;
Sampling needle is in the state of contact or close predetermined object.
9. as claim 7 or 8 described calibration stepss, it is characterized in that described step of regulating the resistance value of himself according to comparative result control variable resistor unit comprises:
If control voltage is lower than target voltage values, then controls the variable resistor unit and increase the resistance value of himself;
If control voltage is higher than target voltage values, then controls the variable resistor unit and reduce the resistance value of himself.
10. as claim 7 or 8 described calibration stepss, it is characterized in that, repeat the described control voltage that actual acquisition is arrived and target voltage values relatively and describedly regulate the step of the resistance value of himself according to comparative result control variable resistor unit, satisfy predetermined condition up to the deviation of controlling voltage and target voltage values.
11. calibration steps as claimed in claim 10 is characterized in that, described predetermined condition comprises any in the following condition:
A. the deviation of controlling voltage and target voltage values is little in predetermined scope;
B. a that do not satisfy condition, but the variable resistor unit has been adjusted to the limit.
12. calibration steps as claimed in claim 10 is characterized in that, after the resistance value of each adjusting variable resistor unit, and the delay adjustments time.
13. calibration steps as claimed in claim 8 is characterized in that, described sampling needle is in the state that does not contact or keep clear of liquid level and other object and is specially, sampling needle be in the predetermined container and contacting container in the state of liquid of predetermined quantity and predefined type.
14. calibration steps as claimed in claim 11 is characterized in that, the deviation of described control voltage and target voltage values is little to be specially in predetermined scope, and the deviation of control voltage and target voltage values reaches minimum value and this value in the scope of being scheduled to.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200910106680 CN101865718B (en) | 2009-04-17 | 2009-04-17 | Liquid level detection circuit, device and calibration method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200910106680 CN101865718B (en) | 2009-04-17 | 2009-04-17 | Liquid level detection circuit, device and calibration method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101865718A CN101865718A (en) | 2010-10-20 |
| CN101865718B true CN101865718B (en) | 2013-09-11 |
Family
ID=42957530
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200910106680 Active CN101865718B (en) | 2009-04-17 | 2009-04-17 | Liquid level detection circuit, device and calibration method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101865718B (en) |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102759661A (en) * | 2011-04-28 | 2012-10-31 | 鸿富锦精密工业（深圳）有限公司 | Testing circuit and testing method for temperature compensating resistor |
| CN102798431B (en) * | 2012-08-30 | 2014-04-09 | 北京京仪海福尔自动化仪表有限公司 | Piezoelectric crystal oscillation and detection device |
| CN103115655A (en) * | 2012-12-19 | 2013-05-22 | 上海博玺自动化科技有限公司 | Frequency conversion liquid level detecting structure |
| CN106352950B (en) * | 2015-07-13 | 2019-03-19 | 桓达科技股份有限公司 | Radar object liquid level measuring device and radar object liquid level measurement method |
| WO2017008249A1 (en) * | 2015-07-14 | 2017-01-19 | 深圳迈瑞生物医疗电子股份有限公司 | Sampling mechanism, skipped-vacuum testing method therefor, and sample analyzer |
| CN106404111B (en) * | 2015-07-29 | 2019-07-05 | 上海凡宜科技电子有限公司 | The anti-interference method of the bearing calibration of capacitance charge level sensing device and plural device |
| CN107655543A (en) * | 2016-07-25 | 2018-02-02 | 中国科学院理化技术研究所 | Phase-locked capacitance liquid level meter |
| CN106643978B (en) * | 2017-01-09 | 2020-07-14 | 迈克医疗电子有限公司 | Data processing method and module |
| CN107870594A (en) * | 2017-11-30 | 2018-04-03 | 四川泛华航空仪表电器有限公司 | A kind of programmable capacitor circuit |
| CN109030807A (en) * | 2018-08-09 | 2018-12-18 | 苏州长光华医生物医学工程有限公司 | The detection system and method for needle are blocked up suitable for cleaning separation function |
| CN111380916B (en) * | 2018-12-29 | 2023-09-15 | 深圳市帝迈生物技术有限公司 | Liquid level detection device and liquid level detection method |
| CN113701714B (en) * | 2021-09-23 | 2024-06-07 | 深圳市微特精密科技股份有限公司 | Method and device for identifying DUT (device under test) leveling calibration by infrared reflection sensor |
| CN113824444B (en) * | 2021-09-29 | 2023-07-28 | 天津津航计算技术研究所 | DAC output self-adaptive calibration device under wide temperature environment |
| CN113824445B (en) * | 2021-09-29 | 2023-07-28 | 天津津航计算技术研究所 | DAC output self-adaptive calibration method in wide temperature environment |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6107810A (en) * | 1996-11-19 | 2000-08-22 | Hitachi, Ltd. | Analyzer with function of detecting liquid level |
| CN101004424A (en) * | 2006-01-20 | 2007-07-25 | 深圳迈瑞生物医疗电子股份有限公司 | Device and method for detecting jam of sample needle of biochemical analyser |
| CN101135584A (en) * | 2006-08-31 | 2008-03-05 | 深圳迈瑞生物医疗电子股份有限公司 | Detecting probe liquid level detector and method |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56129819A (en) * | 1980-03-18 | 1981-10-12 | Nippon Kokan Kk <Nkk> | Eddy current type mold level meter with agc |
| JP3682138B2 (en) * | 1997-02-13 | 2005-08-10 | アロカ株式会社 | Dispensing device |
-
2009
- 2009-04-17 CN CN 200910106680 patent/CN101865718B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6107810A (en) * | 1996-11-19 | 2000-08-22 | Hitachi, Ltd. | Analyzer with function of detecting liquid level |
| CN101004424A (en) * | 2006-01-20 | 2007-07-25 | 深圳迈瑞生物医疗电子股份有限公司 | Device and method for detecting jam of sample needle of biochemical analyser |
| CN101135584A (en) * | 2006-08-31 | 2008-03-05 | 深圳迈瑞生物医疗电子股份有限公司 | Detecting probe liquid level detector and method |
Non-Patent Citations (2)
| Title |
|---|
| JP昭56-129819A 1981.01.02 |
| JP特开平10-227799A 1998.08.25 |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101865718A (en) | 2010-10-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101865718B (en) | Liquid level detection circuit, device and calibration method thereof | |
| US9256228B2 (en) | Mass flow controller with onboard diagnostics, prognostics, and data logging | |
| CN102378917B (en) | System and method of line noise analysis and detection and reduction on sensor signal | |
| CN101858770B (en) | Liquid level detection device and sample adding system | |
| EP1279964B1 (en) | Resistance measuring circuit | |
| KR100247184B1 (en) | Digital trimming of on-chip analog components | |
| US20050174129A1 (en) | Circuit arrangement for capacitive humidity measurement and method for operating the same | |
| CN102914756B (en) | A kind of method of Full-automatic calibration compensation of diode-type microwave power probe | |
| CN101769800A (en) | High-precision temperature checking method and instrument based on ARM | |
| CN109765502B (en) | Program-controlled direct current electronic load | |
| CN106289366A (en) | A kind of automatic calibration of sensor method and batch calibrating installation | |
| CN108718153B (en) | A kind of the Second Order Sliding Mode Control system and control method of Buck DC-DC converter fixed frequency | |
| CN108809271A (en) | A kind of alc circuit and radio-frequency signal source | |
| CN114566685A (en) | Electrolyte flow dynamic control system and method based on vanadium battery SOC estimation | |
| CN101124721A (en) | Digital time constant tracking technique and apparatus | |
| WO2021062844A1 (en) | Apparatus and method for determining polarization voltage of battery, and related device | |
| CN112068610B (en) | Pressure balance flowmeter, flow control system and flow control method | |
| CN114690620A (en) | Electronic load PID self-tuning method and system | |
| CN105720634B (en) | A kind of the charge power current control method and system of self study | |
| CN111077923B (en) | Air supply system of airborne blasting device and control method thereof | |
| CN114371335A (en) | High-precision digital source meter | |
| CN113552529A (en) | Self-calibration system and method based on intelligent electric energy meter online monitoring | |
| US7554388B2 (en) | Integrated circuit apparatus | |
| CN113702851B (en) | Automatic control system for battery voltage sampling time sequence | |
| CN210072357U (en) | High-temperature sensitive pressure sensing control system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| EE01 | Entry into force of recordation of patent licensing contract | ||
| EE01 | Entry into force of recordation of patent licensing contract |
Application publication date: 20101020 Assignee: Shenzhen Mindray Animal Medical Technology Co.,Ltd. Assignor: SHENZHEN MINDRAY BIO-MEDICAL ELECTRONICS Co.,Ltd. Contract record no.: X2022440020009 Denomination of invention: Liquid level detection circuit, device and calibration method thereof Granted publication date: 20130911 License type: Common License Record date: 20220804 |