CN106781889A - A kind of automatic experiment for surveying air relative pressure coefficient and analytical equipment - Google Patents
A kind of automatic experiment for surveying air relative pressure coefficient and analytical equipment Download PDFInfo
- Publication number
- CN106781889A CN106781889A CN201611152770.3A CN201611152770A CN106781889A CN 106781889 A CN106781889 A CN 106781889A CN 201611152770 A CN201611152770 A CN 201611152770A CN 106781889 A CN106781889 A CN 106781889A
- Authority
- CN
- China
- Prior art keywords
- pressure
- rtd
- temperature
- rod assembly
- mechanical pump
- 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.)
- Pending
Links
Classifications
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09B—EDUCATIONAL OR DEMONSTRATION APPLIANCES; APPLIANCES FOR TEACHING, OR COMMUNICATING WITH, THE BLIND, DEAF OR MUTE; MODELS; PLANETARIA; GLOBES; MAPS; DIAGRAMS
- G09B23/00—Models for scientific, medical, or mathematical purposes, e.g. full-sized devices for demonstration purposes
- G09B23/06—Models for scientific, medical, or mathematical purposes, e.g. full-sized devices for demonstration purposes for physics
Abstract
The present invention provides a kind of automatic experiment for surveying air relative pressure coefficient and analytical equipment, including beaker, motor, stirring vane, bubble, heating rod assembly, temperature measurement module, solenoid directional control valve, pressure-detecting device, pressure detecting module, solenoid actuated unit, driven by mechanical pump unit, mechanical pump, PWM control units, stirring motor driver element, MCU units.The device can automatically carry out gas circuit switching, measuring and controlling temp, judge experimental state and complete temperature and pressure Data acquisition and issuance, it is greatly improved the automaticity and experimental data accuracy of experimentation, operation is simplified, intuitive display improves experiment effect.
Description
Technical field
The present invention relates to a kind of e measurement technology, particularly a kind of automatic experiment for surveying air relative pressure coefficient is filled with analysis
Put.
Background technology
It is the given experiment of College Physics outline to survey air relative pressure coefficient with sensor, is related to school and specialty suitable
Extensively.Existing Examination on experimental operation uses decades, experimentation is completed basically by manual operations, as shown in Figure 1.Experiment
Method is first to complete the calibration of differential pressure pickup, it is determined that output voltage Uo and line when diffusion piezoresistive silicon sensor pressure difference is zero
Sex ratio COEFFICIENT K p.With reference to Fig. 9, stop,threeway is slowly rotated, detain the C of differential pressure pick-up and communicated with B pipes and A bubble disconnections, this
When the logical air of C.Plastic tube G is connected on joint H makes D mouthfuls to be connected with mechanical pump.Four Semi-digital voltmeters are connected on into differential pressure to pass
In the output end 3 and 4 of sensor.Start mechanical pump, from D mouthfuls of pumping.Treat that vacuum meter throw of pointer is motionless nearby to 760mm scales
When, now D implications pressure can be considered zero, Ya Cha ⊿ P=Pc, and the output voltage of differential pressure pick-up is Um.Then mechanical pump is stopped, from
Plastic tube G is taken out on joint H, makes D mouthfuls also to lead to air.Ci Shi ⊿ P0=0, the reading of digital voltmeter is U0.Then relation of the pressure sensor signal with temperature inversion is measured.The slow stop,threeway that rotates makes C mouthfuls to be steeped with A
Communicate.The output voltage values Up of copper wire magnitude of voltage Ut and differential pressure pickup at room temperature is recorded, regulation constant-current source is heated to copper wire,
Relation (Ut, Up) in record temperature elevation process between copper wire magnitude of voltage Ut and the output voltage values Up of differential pressure pickup.From
And draw the Ut-Up relation curves of reaction air relative pressure coefficient.
Operation above completes experimental implementation and measurement basically by manual mode, and it is that operation is repeated several times that it has problem
Efficiency is low and easy error；Temperature control is carried out to copper wire heating using regulation constant-current source manually, this temperature control method, due to
It is low using open loop approach control accuracy, it is impossible to ensure the thermal balance of temperature in bubble；Agitator is needed to use to enter manually during heating
Row stirring, controls thermal balance, to ensure accuracy of reading, if local heating is quickly, Ut and Up can be caused constantly to convert, it is impossible to
Record data.Data collection and analysis are by being accomplished manually, and the operation cycle is long, and efficiency is low, and going wrong needs to process afterwards, experiment
Process data is unable to Real-time Collection, treatment, analysis and shows, whole experiment process lags far behind modern experimental method and measurement
Technology.
The content of the invention
It is an object of the invention to provide a kind of automatic experiment for surveying air relative pressure coefficient and analytical equipment, the device
Gas circuit switching, measuring and controlling temp can be automatically carried out, experimental state is judged and is completed temperature and pressure Data acquisition and issuance, can be big
The big automaticity and experimental data accuracy for improving experimentation, simplifies operation, and intuitive display improves experiment effect
Really.
A kind of automatic experiment for surveying air relative pressure coefficient and analytical equipment, including beaker, motor, stirring vane, gas
Bubble, heating rod assembly, temperature measurement module, solenoid directional control valve, pressure-detecting device, pressure detecting module, solenoid actuated unit, machine
Tool pump driver element, mechanical pump, PWM control units, stirring motor driver element, MCU units；Wherein stirring vane is arranged at Sheng
Have in the beaker of liquid and rotation is driven by motor, stirring motor driver element, bubble is arranged at beaker inscribe by output
Pipeline is connected with solenoid directional control valve first port, and heating rod assembly is arranged in beaker, and temperature measurement module is divided into two-way, wherein all the way
It is that the thermometer that is arranged in beaker and another road be connecteds with heating rod assembly, pressure-detecting device and the end of solenoid directional control valve second
Mouth connection, pressure detecting module is connected with pressure-detecting device, and solenoid actuated unit connects with the magnet coil of solenoid directional control valve
Connect, mechanical pump is connected with the port of solenoid directional control valve the 3rd, and driven by mechanical pump unit is connected with mechanical pump, PWM control units with plus
Hot pin component connect, MCU units respectively with temperature measurement module, pressure detecting module, solenoid actuated unit, driven by mechanical pump list
Unit, the connection of PWM control units, stirring motor driver element；The solenoid directional control valve has in the presence of solenoid actuated unit
There are two working positions, wherein mechanical pump and pressure-detecting device UNICOM, bubble and pressure during the second working position during the first working position
Detection means UNICOM.
Using said apparatus, device also includes that the acousto-optic warning unit being connected with MCU units, LCD display unit, USB drive
Moving cell, keyboard.
Prior art of the present invention is compared, with advantages below：
(1) temperature measurement module of the present invention and pressure-detecting device, can synchronously be automatically performed the measurement of pressure-temperature data, and
Manual adjustment need not be carried out；The temperature data that temperature measurement module feeds back is analyzed and processed using MCU units, is then passed through
PWM driver elements carry out closed-loop control to heating rod assembly, and the temperature control to burning water in the cup is more accurate.
(2) present invention is connected by heating rod assembly with temperature measurement module, and energy effective monitoring temperature prevents heating wire dry combustion method；Profit
With data such as the timely displays temperatures of LCD display energy；The communication with host computer can be realized using USB driver elements, by host computer
Control it and treatment is analyzed to gathered data；Alarm is carried out using audible-visual annunciator to abnormal work device to carry
Show；Using the process of input through keyboard experiment parameter Control release.
(3) present invention surveys the automatic experiment of air relative pressure coefficient and analytical equipment and can carry out automatically accurate, in an orderly manner
Experimental implementation and data acquisition, analysis and display, improve to temperature controlled precision, and experimentation more facilitates, behaviour
Make simpler, drastically increase conventional efficient；And because experiment test task automation is carried out, the standard of experiment can be improved
True property, experimenter's more energy of input that freed from cumbersome work are analyzed and studied to experimental result；Protect
Each experimental result is hindered and has performed the uniformity of content, so as to reach the repeatability and accuracy of experiment.
With reference to Figure of description, the invention will be further described.
Brief description of the drawings
Fig. 1 is that the present invention surveys the automatic experiment of air relative pressure coefficient and the structural representation of analytical equipment.
Fig. 2 is that the automatic experiment of air relative pressure coefficient and the system block diagram of analytical equipment are surveyed in invention.
Fig. 3 is the structural representation of heating rod assembly in Fig. 1.
Fig. 4 is two-way temperature measurement module block diagram in Fig. 1.
Fig. 5 is the signal conditioning circuit schematic diagram of temperature survey.
Fig. 6 is the signal conditioning circuit schematic diagram of pressure measxurement.
Fig. 7 is the control block diagram of PWM driving heating systems in Fig. 2.
Fig. 8 is the P-t curve maps of air relative pressure coefficient.
Fig. 9 is prior art construction schematic diagram.
Specific embodiment
As shown in figure 1, the automatic experiment that the present invention surveys air relative pressure coefficient includes with analytical equipment：Stirring motor 1,
Grip device 3, beaker 4, stirring vane 5, support 14, bubble 6, heating rod assembly 7, the logical electromagnetic switch of mechanical pump 17, two five
Valve 9, pressure-detecting device 10, pressure detecting module 11, solenoid actuated unit 12, the control of driven by mechanical pump unit 13, PWM are single
Unit 15, temperature measurement module 8, stirring motor driver element 16.
As shown in Fig. 2 the automatic experiment that the present invention surveys air relative pressure coefficient includes with analysis system：MCU units 20,
LCD display unit 21, keyboard 22, acousto-optic warning unit 23, USB driver elements 24.There is MCU units 20 PWM outputs, SPI to lead to
News, USB driver elements and correlation function, and with data cut-off protection function.Wherein PWM outputs are that a dutycycle is dynamically adjusted
The process of section, SPI communications can continuously measure multichannel RTD signals.Beaker 4 is used for depositing water.Fixed support 5 be used for fix beaker 4,
Mixing component 5 and RTD sensor 2.RTD sensor 2 is inserted vertically into beaker, and the temperature signal of RTD sensor 2 is exported and two-way
The input of temperature measurement module 8 is connected.The heating oblique cutting of rod assembly 7 enters beaker bottom, the road temperature signal output of heating rod assembly 7 one and list
The input of channel Temperature Measuring module 6 is connected, and the heating input of heating rod assembly 7 one tunnel is connected with the output of PWM driver elements 15.MCU units 20
Input is connected with two-way temperature measurement module 8, and output end is connected with PWM driver elements 15.USB driver elements 24 and MCU units 20
It is connected.The output end of MCU units 20 is connected with LCD display 21 and acousto-optic warning unit 23 respectively.Keyboard 22 and MCU units 20
Input be connected.
With reference to Fig. 3, above-mentioned heating rod assembly 7 includes：
Outer tube 71, heating wire 72, heat conductive silica gel 73 and RTD temperature transducers 74.Heating wire 72 receives MCU units 20
The output signal that PWM drives carries out numerical-control heating, and the heat conductive silica gel 73 of the lumen loading of outer tube 71 is by the heat transfer of heating wire 72
Liquid, the temperature of the module of RTD temperature transducers 74 measurement liquid is simultaneously communicated by SPI interface with MCU units 20, realizes heating
The closed-loop control of temperature.
With reference to Fig. 4, above-mentioned two-way temperature measurement module 8 includes：Constant-current source 81, reference voltage 82, RTD incoming ends 83, RTD are accessed
Amplify and A/D modules 85 at end 84, signal.Constant-current source 81 (LM334) produces constant current signal (400uA) output defeated with reference voltage 82
Enter to be connected and obtain 2.5V reference power sources, the output of reference voltage 82 is connected with signal amplification with A/D modules 86 (AD7705) input.
Constant-current source 81 produces constant current signal output through reference voltage 82 to the input bias current of RTD incoming ends 83, and RTD incoming ends 83 are produced
Temperature signal is input into (passage 1) with A/D modules 85 and is connected with signal amplification.Constant-current source 81 produces constant current signal output through with reference to electricity
Pressure 82 produces temperature signal to amplify defeated with A/D modules 85 with signal to the input bias current of RTD incoming ends 84, RTD incoming ends 84
Enter (passage 2) to be connected.Signal amplifies with A/D modules 85 to dock shrinkage temperature signal and is amplified and converted with A/D and by spi bus
It is connected with the input of MCU units 20.
With reference to Fig. 5 and Fig. 6, temperature signal and pressure signal are small-signal, can use high-gain, the measurement of low disturbance
Amplifier.
With reference to Fig. 5, if T1 is the temperature of beaker reclaimed water, T2 is heater inner chamber temperature, and T3 is that exocoel degree is poor in heater
T3=T1-T2, temperature difference T3 Bianization Shuai ⊿ T3/ ⊿ t, the control mode for being driven heating using PWM is：From water is stretched into
Heater (heating rod assembly 7) carries out temperature feedback (T3 and ⊿ T3), and itself and dry combustion method are judged into dmax carries out application condition analysis,
(the micro- point of letter ⊿ T3/ ⊿ t of T3 is produced after (carrying out differential numerical analysis to T3 signals), such as through excess temperature D adjustment units
Represent that heating rod assembly 7 is in abnormal operation, it is impossible to heated using PWM driver elements；Such as
Heated using PWM driver elements.
Temperature feedback T1, T2 are carried out in TD sensors from water is stretched into Ji ⊿ T3, it is entered with thermal equilibrium state condition
Row application condition is analyzed, and realizes being controlled PWM driver elements by temperature PI adjustment units, and its control voltage is
Control condition is u2(t) ＜ dΔ.Wherein KpIt is scale factor, d△For in heating rod exocoel temperature difference it is maximum allowable
Control errors value.
The automatic experiment of the survey air relative pressure coefficient with analytical equipment when being tested, the output of MCU units 20
Input with the unit of driven by mechanical pump 13 is connected, and the output of driven by mechanical pump unit 13 is connected with the input of mechanical pump 17；MCU is mono-
The output of unit 20 is connected with the input of electromagnetic drive unit 11, the output of electromagnetic drive unit 11 and the input phase of solenoid directional control valve
Even, pipeline switching and the vacuum pumping structure of experimental provision are thus constituted.
MCU units 20 export PWM modulation signal and are connected with the input of PWM driver elements 15, and PWM driver elements 15 are exported and added
The input of hot pin component 7 is connected, and heating rod assembly 7 is fed water and heats, with reference to Fig. 4, the built-in TD temperature transducers of heating rod assembly 7
74 collecting temperature signal outputs are connected with the input of two-way temperature measurement module 8, and the temperature data of two-way temperature measurement module 8 is exported and MCU units
20 inputs are connected, and thus constitute the closed loop heater and temperature control system of water.TD sensors 2 collection water temperature signal output with
The input of two-way temperature measurement module 8 is connected, and the output of the temperature data of two-way temperature measurement module 8 is connected with the input of MCU units 20.Pressure detecting is filled
The output for putting 10 is connected with the input of pressure detecting module 11, pressure detecting module 8 output and MCU units 20 input phase
Even.
MCU units 20 are analyzed to data, process and store, and are connected exporting to be input into LCD display 21, LCD
Display screen 21 shows experimental data and curve.MCU units 20 when experimental provision working condition exception is detected, control by output alarm
Signal processed is connected with the input of audible-visual annunciator 23.Through the output of USB driver elements 24 be uploaded to the data of collection by MCU units 20
Position machine, host computer is further processed to data, and carries out reality by the control main controller MCU of USB driver elements 24 units 20
Test operation.Keyboard 22 is used for the process and parameter of Control release.
When starting experiment, first, the output of MCU units 20 controls the right position of solenoid directional control valve 9 by solenoid actuated unit 12
Work, now mechanical pump 17 is connected with one end of pressure sensor 10, treats that be pumped into for one end of pressure sensor by mechanical pump near true
Space-time (vacuum meter reading is 760mm), presses button, and MCU units 20 write down one end of pressure sensor by AD sampling functions
Output voltage Um in the state of vacuum, one end atmospheric pressure；Then the output of MCU units 20 is caused by solenoid actuated unit 11
The dead electricity of solenoid directional control valve 9, under the effect of spring restoring force, the work of the left position of solenoid directional control valve 9.The efferent duct of bubble 6 and pressure
One end of force snesor 10 is connected, and MCU units 20 measure pressure sensor and are in two-way input pressure difference by AD sampling functions
Output voltage U0 when zero.Calculated according to Um, U0 and Pc and calculate linear scale factor Kp.Such that it is able to according to the voltage surveyed
Value U is converted into corresponding pressure value P.Measure real-time temperature value simultaneously, you can obtain P-t curves.
Claims (7)
1. it is a kind of survey air relative pressure coefficient automatic experiment and analytical equipment, it is characterised in that including beaker (4), motor
(1), stirring vane (5), bubble (6), heating rod assembly (7), temperature measurement module (8), solenoid directional control valve (9), pressure-detecting device
(10), pressure detecting module (11), solenoid actuated unit (12), driven by mechanical pump unit (13), mechanical pump (17), PWM controls
Unit (15) processed, stirring motor driver element (16), MCU units (20)；Wherein
Stirring vane (5) is arranged in the beaker (4) for filling liquid and is driven by motor (1), stirring motor driver element (16)
Dynamic rotation,
Bubble (6) is arranged at beaker (4) inscribe and is connected with solenoid directional control valve (9) first port by output channel,
Heating rod assembly (7) is arranged in beaker (4),
Temperature measurement module (8) is divided into two-way, wherein being all the way the thermometer being arranged in beaker (4) and another road and heating rod assembly
(7) connect,
Pressure-detecting device (10) is connected with solenoid directional control valve (9) second port,
Pressure detecting module (11) is connected with pressure-detecting device (10),
Solenoid actuated unit (12) is connected with the magnet coil of solenoid directional control valve (9),
Mechanical pump (17) is connected with the port of solenoid directional control valve (9) the 3rd,
Driven by mechanical pump unit (13) is connected with mechanical pump (17),
PWM control units (15) are connected with heating rod assembly (7),
MCU units (20) drive with temperature measurement module (8), pressure detecting module (11), solenoid actuated unit (12), mechanical pump respectively
Moving cell (13), PWM control units (15), stirring motor driver element (16) connection；
The solenoid directional control valve (9) has two working positions in the presence of solenoid actuated unit (12), wherein the first work
Mechanical pump (17) and pressure-detecting device (10) UNICOM during position, bubble (6) joins with pressure-detecting device (10) during the second working position
It is logical.
2. device according to claim 1, it is characterised in that the condition of work of heating rod assembly (7) isIts
Middle T3=T1-T2, T1It is water temperature, T in beaker (4)2It is the temperature of heating rod assembly (7), Δ t is the time,It is to T3Signal
T is produced after carrying out differential numerical analysis3Differential letter, number dmaxIt is the most fast rate of temperature change of setting.
3. device according to claim 2, it is characterised in that condition during pressure measxurement is T3≤ 0,
4. the device according to Claims 2 or 3, it is characterised in that the control voltage of PWM control units (15) isWherein, KpIt is scale factor；
Control condition is u2(t) ＜ dΔ, dΔIt is T3Limits of error controlling value.
5. device according to claim 1, it is characterised in that heating rod assembly (7) includes outer tube (71), heating wire
(72), heat conductive silica gel (73), RTD temperature transducers (74)；Wherein
The output signal that heating wire (72) receives MCU units (20) carries out numerical-control heating,
The heat conductive silica gel (73) of outer tube (71) lumen loading by the heat transfer liquid of heating wire (72),
The temperature of RTD temperature transducers (74) module measurement liquid simultaneously communicates with MCU units (20).
6. device according to claim 1, it is characterised in that temperature measurement module (8) includes constant-current source (81), reference voltage mould
Block (82), a RTD incoming ends (83), the 2nd RTD incoming ends (84), signal amplify and A/D modules (85)；Wherein
Constant-current source (81) output end is connected with reference voltage module (82) input, two output ends of reference voltage module (82)
It is connected with a RTD incoming ends (83), the 2nd RTD incoming ends (84) input respectively, a RTD incoming ends (83), the 2nd RTD
Incoming end (84) output end is connected with signal amplification with A/D modules (85) input respectively, and signal amplifies defeated with A/D modules (85)
Go out end to be connected with MCU units (20)；
First RTD incoming ends (83) connect the thermometer being arranged in beaker (4),
2nd RTD incoming ends (84) connect heating rod assembly (7).
7. device according to claim 1, it is characterised in that device also includes the acousto-optic report being connected with MCU units (20)
Alert unit (23), LCD display unit (21), USB driver elements (24), keyboard (22).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201611152770.3A CN106781889A (en) | 2016-12-14 | 2016-12-14 | A kind of automatic experiment for surveying air relative pressure coefficient and analytical equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201611152770.3A CN106781889A (en) | 2016-12-14 | 2016-12-14 | A kind of automatic experiment for surveying air relative pressure coefficient and analytical equipment |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN106781889A true CN106781889A (en) | 2017-05-31 |
Family
ID=58888453
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201611152770.3A Pending CN106781889A (en) | 2016-12-14 | 2016-12-14 | A kind of automatic experiment for surveying air relative pressure coefficient and analytical equipment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106781889A (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1719228A (en) * | 2004-07-09 | 2006-01-11 | 北京林业大学 | Vacuum overheat steam drying experimental device for wood material and its detecting method |
| CN103604826A (en) * | 2013-11-28 | 2014-02-26 | 南京工业职业技术学院 | Automatic experiment and analysis device for gas-liquid equilibrium phase diagram of binary liquid solution |
-
2016
- 2016-12-14 CN CN201611152770.3A patent/CN106781889A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1719228A (en) * | 2004-07-09 | 2006-01-11 | 北京林业大学 | Vacuum overheat steam drying experimental device for wood material and its detecting method |
| CN103604826A (en) * | 2013-11-28 | 2014-02-26 | 南京工业职业技术学院 | Automatic experiment and analysis device for gas-liquid equilibrium phase diagram of binary liquid solution |
Non-Patent Citations (2)
| Title |
|---|
| 杨长铭 等: "《物理实验》", 30 September 2010, 武汉大学出版社 * |
| 金雪尘 等: "《大学物理实验》", 31 January 2009 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN203719811U (en) | Weak voltage signal detection device of micro-voltage sensor | |
| CN103234662A (en) | Compensation method for automatic temperature detection and automatic temperature detection system | |
| CN201993202U (en) | Calibrating device for pressure sensor or transmitter | |
| CN106338323B (en) | A kind of flowmeter in-situ calibration method and verification system | |
| CN103616129A (en) | Automatic calibration method for tension and compression residual stress ultrasonic detection system | |
| CN102707017A (en) | Test system for detecting integrity and reliability of gas monitoring system | |
| CN104977430B (en) | One kind is without wind-tunnel virtual thermal air velocity transducer test device | |
| CN206311462U (en) | A kind of self-operated measuring unit of neat liquid saturated vapor pressure | |
| CN103759651B (en) | A kind of alternating temperature of monitoring in real time variable-pressure laser speckle measurement system | |
| CN103616317B (en) | A kind of fully-automatic equipment of assaying reaction heap material helium diffuse coefficient and method | |
| CN208520523U (en) | A kind of calibrating installation of dynamic pressure measurement little differential pressure sensor | |
| CN106781889A (en) | A kind of automatic experiment for surveying air relative pressure coefficient and analytical equipment | |
| CN104020188A (en) | Unfavorable conductor heat conduction coefficient measuring device and unfavorable conductor heat condution coefficient measuring method | |
| CN104849309A (en) | Intelligent tester and testing method for testing gas ratio and heat capacity ratio | |
| CN100561195C (en) | The non-disperse infrared spectrum determination method and the device that are suitable for wide environmental temperature range | |
| CN103604826B (en) | A kind of vapor-liquid equilibrium phasor of binary liquid solution is experiment and analytical equipment automatically | |
| CN105372288B (en) | A kind of rate of heat flow measuring instrument and measuring method | |
| CN201926903U (en) | Online analyzer for liquid density and content | |
| CN109144149B (en) | Automatic control system and experimental method for vacuum heat treatment furnace | |
| CN110836799A (en) | Suction control type rapid unsaturated soil sample preparation control system and method | |
| CN110243877A (en) | A kind of fast gas quantitative testing device suitable for multiple gases | |
| CN105928697A (en) | Gas valve response time measuring device and method | |
| CN105547484B (en) | For the pixel rdaiation response scaling method of linear array detector reliability screening | |
| CN109813866A (en) | The measuring system and measurement method of unsaturation frozen soil matric potential | |
| CN201936204U (en) | Device for measuring and controlling internal temperature of operational amplifier chip |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20170531 |