CN205210058U - Formaldehyde tester - Google Patents
Formaldehyde tester Download PDFInfo
- Publication number
- CN205210058U CN205210058U CN201521074352.8U CN201521074352U CN205210058U CN 205210058 U CN205210058 U CN 205210058U CN 201521074352 U CN201521074352 U CN 201521074352U CN 205210058 U CN205210058 U CN 205210058U
- Authority
- CN
- China
- Prior art keywords
- sensor
- circuit
- unit
- gas circuit
- gas
- 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
Landscapes
- Investigating Or Analyzing Materials By The Use Of Fluid Adsorption Or Reactions (AREA)
Abstract
The utility model provides a formaldehyde tester, including sensor, gas circuit air chamber unit, signal acquisition and processing unit and microprocessor unit, gas circuit air chamber unit includes the holding the sensor chamber room of sensor, with test gas circuit that sensor chamber room one side links to each other, with the test gas circuit is parallelly connected to be set up the calibration gas circuit of sensor chamber room homonymy, and set up the air exhaust device of sensor chamber room opposite side, test gas circuit one end awaits measuring gaseous linking to each other with the external world, the other end with the sensor chamber room links to each other, the signal acquisition and processing unit with microprocessor unit with sensor electric connection, air exhaust device with microprocessor electric connection, the utility model discloses can calibrate the demarcation of sensor self, prevent that sensor self drift from influencing the measuring degree of accuracy, makes the test result accurate reliable.
Description
Technical field
The utility model relates to a kind of formaldehyde tester, belongs to field of gas detection.
Background technology
Formaldehyde is that one can bring out various diseases, and has the harmful gas of carcinogenicity.Formaldehyde gas in household, working environment has become the major reason be detrimental to health, and causes showing great attention to of people.According to China's national Specification: in indoor air, the maximum permissible concentration of formaldehyde is 0.08 milligram/cubic metre, the maximum permissible concentration of public place formaldehyde is 0.10 milligram/cubic metre.
At present, measurement formaldehyde gas the most accurately method is chromatography, but the method needs by means of large-scale precision instrument, expensive, can not generally use.Existing also have a kind of detection adopting the development process of chemical reagent to carry out concentration of formaldehyde, but the method needs to use chemical reagent to carry out the method detected, the concentration of formaldehyde is judged by reagent color change after adsorbing extraneous formaldehyde, but this chemical reagent is only single use, its test duration is long, and result can not quantitatively and easy contaminated environment.
In recent years, people have also been developed some formaldehyde testers, but the main concentration still carrying out quantitative test formaldehyde with electrochemical sensor, precision of its test is lower, price is higher, hinders a large amount of uses of this small portable testing apparatus.
In view of this, be necessary to provide a kind of formaldehyde tester of improvement to solve the problem.
Utility model content
The purpose of this utility model is to provide one can carry out self-alignment formaldehyde tester to transducer calibration, this formaldehyde tester have can carry, detect fast, power consumption is little and cost is low advantage.
For realizing above-mentioned utility model object, the utility model provides a kind of formaldehyde tester, comprise sensor, gas circuit air chamber unit, signal acquisition process unit and microprocessor unit, described gas circuit air chamber unit comprises the sensor cavities of accommodating described sensor, the test gas circuit be connected with described sensor cavities side, the calibration gas circuit at described sensor cavities homonymy is arranged in parallel with described test gas circuit, and be arranged on the air extractor of described sensor cavities opposite side, described test gas circuit one end is connected with external world's gas to be measured, the other end is connected with described sensor cavities,
Described signal acquisition process unit and described microprocessor unit and described sensor are electrically connected, and described air extractor and described microprocessor are electrically connected.
As further improvement of the utility model, the first airtight gas channels that described calibration gas circuit comprises purification chamber, is connected with ambient atmos by described purification chamber, and the second airtight gas channels that described purification chamber is connected with described sensor cavities.
As further improvement of the utility model, described sensor cavities has an entrance gas channels, the entrance gas channels of described sensor cavities is provided with and described test gas circuit and the gas path switching device calibrated gas circuit and be connected.
As further improvement of the utility model, described gas path switching device has Chang Kaiduan and normal-closed end, and described Chang Kaiduan is connected with described test gas circuit, and described normal-closed end is connected with described calibration gas circuit.
As further improvement of the utility model, described purification chamber includes multilayer acticarbon, and adjacent two layers is separately fixed on the relative sidewall of purification chamber two, is crisscross arranged to make the acticarbon in two opposing sidewalls.
As further improvement of the utility model, the gas access place of described sensor cavities is provided with fair water fin.
As further improvement of the utility model, described signal acquisition process unit comprises the signal condition change-over circuit of setting parallel with one another, constant-current circuit and exciting circuit, one end of described conditioning change-over circuit, constant-current circuit and exciting circuit is connected with described microprocessor, and one end is connected with described sensor.
As further improvement of the utility model, described formaldehyde tester also comprises the radio communication unit that one end is connected with described microprocessor, and described radio communication unit is bluetooth communication module or WiFi module.
As further improvement of the utility model, described formaldehyde tester also comprises the power supply unit, storage unit, display unit and the alarm unit that are electrically connected with described microprocessor.
As further improvement of the utility model, described exciting circuit, gas path switching device and extractor fan adopt independent voltage stabilizing to power.
The beneficial effects of the utility model are: the utility model formaldehyde tester is before test starting, calibration gas circuit is utilized to purify sensor self, thus reach transducer calibration is calibrated, the accuracy preventing sensor self-resistance drift effect from measuring, makes test result accurately and reliably.
After calibration is completed to described sensor, calibration gas channels is switched to test gas channels,
By arranging the flowing that air extractor makes gas to be measured stable and uniform in the sensor in test gas channels, realize the Quick Measurement to gas to be measured.
Accompanying drawing explanation
Fig. 1 is the module diagram of the utility model formaldehyde tester.
Fig. 2 is the air chamber gas circuit cell schematics in the utility model one preferred embodiment.
Embodiment
Being described in detail the utility model below with reference to each embodiment shown in the drawings, is below the utility model one better embodiment.
Refer to shown in Fig. 1 to Fig. 2, the utility model relates to a kind of formaldehyde tester 100, comprise sensor 10, gas circuit air chamber unit 20, signal acquisition process unit, power supply unit, storage unit, display unit, alarm unit, radio communication unit and microprocessor unit, described signal acquisition process unit, power supply unit, storage unit, display unit, alarm unit, radio communication unit and described microprocessor unit are electrically connected.
Described sensor 10 is novel resistor-type nano material formaldehyde sensor, the response of ppb level concentration of formaldehyde can be realized, there is higher sensitivity, described sensor 10 also has advantage low in energy consumption, it particularly adopts Semiconductor gas sensors material to make, operating temperature range is 100-180 DEG C, when drift can be there is in the resistance of described sensor 10, the activation voltage of 3.5-5.0V only need be provided described sensor 10, with the activationary time of 10min-1000min, 180-300 DEG C of activationary temperature can be produced.The activation voltage of described sensor 10, activationary time and working temperature are all lower than common formaldehyde sensor.
In the present embodiment, the model of described sensor 10 is NGTFS-14a, and certainly in other embodiments, described sensor 10 can select other model.
Described gas circuit air chamber unit 20 comprises the sensor cavities 21 of accommodating described sensor 10, the test gas circuit 22 be connected with described sensor cavities 21 side and the air extractor 23 being arranged on described sensor cavities 21 opposite side and is arranged in parallel the calibration gas circuit 24 at described sensor cavities 21 homonymy with described test gas circuit 22.
One end of gas circuit air chamber unit 20 and signal acquisition process unit is all electrically connected with described microprocessor unit, the other end is also all electrically connected with described sensor 10, and the unidirectional and described microprocessor unit of described power supply unit, storage unit, display unit and alarm unit is connected.
Described sensor cavities 21 is closed structure, and be provided be positioned at described test gas circuit 22 side entrance gas channels 25, be arranged on the air intake 211 on described entrance gas channels 25 and be positioned at the gas outlet 213 of described air extractor 23 side, air intake 211 place of described sensor cavities 21 is provided with fair water fin 212, to ensure that the uniform and stable of air-flow flows through described sensor cavities 21 and described sensor 10, improve the accuracy measured.Described test gas circuit 22 one end is connected with external world's gas to be measured, and the other end is connected with described sensor cavities 21.Described air extractor 23 is a micropump, be electrically connected with described microprocessor, and being arranged on gas outlet 213 place of described sensor cavities 21, described air extractor 23, by gas to be measured for the external world is pumped to described sensor 10 fast, is conducive to the speed and the sensitivity that improve detection.
The first airtight gas channels 242 that described calibration gas circuit 24 comprises purification chamber 241, is connected with external world's gas to be measured by described purification chamber 241, and the second airtight gas channels 243 that described purification chamber 241 is connected with described sensor cavities 21, described entrance gas channels 25 is provided with and described test gas circuit 22 and the gas path switching device 244 be connected calibrating gas circuit 24.Described gas path switching device 244 has Chang Kaiduan and normal-closed end, and described Chang Kaiduan is connected with described test gas circuit 22, and described normal-closed end is connected with described calibration gas circuit 24.In the present embodiment, described gas path switching device 244 is solenoid valve.For reducing the power consumption of system, the opening and closing of solenoid valve is controlled by two metal-oxide-semiconductor control circuits, and the calibrate stage of solenoid valve only before testing opens, and is in off position, not power consumption when testing described sensor 10.
Described purification chamber 241 includes multilayer acticarbon 246, adjacent two layers is separately fixed on the relative sidewall 245 of described purification chamber 241 two, be crisscross arranged to make the described acticarbon 246 in two opposing sidewalls 245, setting like this, extraneous gas to be measured can be made in described purification chamber 241 to have the longest path that flows through, thus ambient atmos effectively can be purified through long-time, to improve the precision of pick up calibration.When air to be measured carries out content of formaldehyde test to the described formaldehyde tester 100 of employing to external world, first press corresponding function button and start test, described microprocessor unit controls to calibrate gas circuit 24 described in the conducting of described gas path switching device 244, and control described air extractor 23 and start exhausting, ambient atmos obtains clean gas for calibrating the benchmark calibration of described sensor 10 after described purification chamber 241.After described sensor 10 has been calibrated, described test gas circuit 22 is connected by described gas path switching device 244, now external air flow is directly pumped to the sensor 10 in described sensor cavities 21 by described air extractor 23, when the content of formaldehyde concentration in air to be measured exceedes the benchmark of described sensor 10 setting, described alarm unit just can send chimes of doom, and concentration is shown by described display unit, to realize measuring the content of formaldehyde in extraneous gas to be measured.Described display unit is LCDs, and for showing concentration of formaldehyde information, the model of described LCDs is JLT24009A.
Described signal acquisition process unit comprises the signal condition change-over circuit of setting parallel with one another, constant-current circuit and exciting circuit, one end of described conditioning change-over circuit, constant-current circuit and exciting circuit is connected with described microprocessor, and one end is connected with described sensor 10.Described signal condition change-over circuit comprises the filtering circuit, voltage follower circuit, the A/D convertor circuit that are connected in series, described constant-current circuit is used for powering when measuring to described sensor 10, described constant-current circuit forms zero temp shift circuit by components and parts such as LM334 and diode IN149, and electric current is set to 20uA.Low-pass filter circuit is adopted in described filtering circuit, by set of frequency at about 100Hz, AD conversion chip adopts high-precision AD chip ADS1100, and gives described microprocessor unit by IIC communication mode by digital data transmission, and transfer rate is arranged on 400KHz.
Described exciting circuit is made up of an adjustable voltage stabilizing chip, and output voltage is 3.5V ~ 5V, produces the temperature of 180 ~ 300 DEG C in described sensor 10.Because described sensor 10 is exposed in the air containing impurity for a long time, described sensor 10 may be subject to the ectocines such as poisoning, pollution and cause the resistance of described sensor 10 to drift about, described exciting circuit can provide an activation voltage to the resistance of described sensor 10, and produce desorption after described sensor 10 is heated, recover sensitivity, make the resistance of described sensor 10 come back to normal operating conditions, thus ensure that the performance of described sensor 10 does not make performance degradation because using time long.
Described power supply unit is powered to above-mentioned each unit by a joint 3.7V lithium battery, due to operating voltage requirement and the stability requirement difference of other each unit, power to it respectively by corresponding low pressure difference linearity voltage stabilizing chip, wherein said microprocessor unit adopts XC6206P302M voltage stabilizing chip to power to it; Described gas path switching device 244, described aspirator 23 and described exciting circuit adopt the XC6206P302P voltage stabilizing chip of relatively high power to carry out independently-powered to it, reduce the impact on system, improve the stability of system.Described power supply unit is integrated wired and wireless charging circuit also, and wherein wireless charging circuit adopts and meets the charge coil of Qi standard and overcharge protection circuit is connected with lithium battery.
Described radio communication unit is bluetooth communication module or WiFi module.In the present embodiment, described radio communication unit adopts Bluetooth technology to carry out exchanges data by serial ports connected mode and described microprocessor unit, wireless blue tooth adopts transparent transmission mode to be connected with the personal terminal such as mobile phone, PC, to realize test data being transferred to personal terminal and utilizing personal terminal to carry out the operations such as control to equipment.
Described microprocessor unit comprises single-chip microcomputer and relevant peripheral circuit, described formaldehyde tester 100 also comprises function keyboard, storage chip, clock chip and humiture module, and described function keyboard, storage chip, clock chip and humiture module are directly connected with described single-chip microcomputer is unidirectional.Described signal acquisition process unit is when processing described sensor 10 signal recorded, first the voltage signal of described sensor 10 is changed into formaldehyde gas concentration information through calculating, and be presented on described display unit, time and result are stored on described storage chip simultaneously, described storage chip adopts EEPROM24AA512 chip, and this storage chip carries out exchanges data by IIC communication mode with 400KHz speed and described single-chip microcomputer.Meanwhile, for ensureing the accuracy of test, employing is repeatedly averaged method and carries out data acquisition, and one-time detection gathers 128 secondary data and averages.And when single-chip microcomputer idle condition, system enters dormant state, to reduce power consumption.In the present embodiment, the model of described clock chip is DS1302, and the sensor model number that described humiture module adopts is AM2320.
In sum, the utility model is by before described formaldehyde tester 100 test starting, described calibration gas circuit 24 is utilized to purify described sensor 10, thus reach the demarcation of described sensor 10 self is calibrated, make test result accurately and reliably, prevent the accuracy that described self drift effect of sensor 10 is measured.
After described sensor 10 has been calibrated, by described calibration gas circuit 24 passage bridge to described test gas circuit 22 passage, by arranging described air extractor 23 in described test gas circuit 22 passage, to make the flowing of gas to be measured stable and uniform in described sensor cavities 21, realize measuring the fast accurate of gas to be measured.In addition, described formaldehyde tester 100 also has that power consumption is little, cost is low, compact, system adopts low-power consumption STM8S series monolithic as main control chip, complete machine is powered by a joint lithium battery, and the functions such as integrated wireless telecommunications, wireless charging, easy to use, be conducive to large-scale application.
Be to be understood that, although this instructions is described according to embodiment, but not each embodiment only comprises an independently technical scheme, this narrating mode of instructions is only for clarity sake, those skilled in the art should by instructions integrally, technical scheme in each embodiment also through appropriately combined, can form other embodiments that it will be appreciated by those skilled in the art that.
A series of detailed description listed is above only illustrating for feasibility embodiment of the present utility model; they are also not used to limit protection domain of the present utility model, all do not depart from the utility model skill equivalent implementations of doing of spirit or change all should be included within protection domain of the present utility model.
Claims (10)
1. a formaldehyde tester, it is characterized in that, comprise sensor, gas circuit air chamber unit, signal acquisition process unit and microprocessor unit, described gas circuit air chamber unit comprises the sensor cavities of accommodating described sensor, the test gas circuit be connected with described sensor cavities side, is arranged in parallel the calibration gas circuit at described sensor cavities homonymy with described test gas circuit, and be arranged on the air extractor of described sensor cavities opposite side, described test gas circuit one end is connected with external world's gas to be measured, and the other end is connected with described sensor cavities;
Described signal acquisition process unit and described microprocessor unit and described sensor are electrically connected, and described air extractor and described microprocessor are electrically connected.
2. formaldehyde tester according to claim 1, it is characterized in that: the first airtight gas channels that described calibration gas circuit comprises purification chamber, is connected with ambient atmos by described purification chamber, and the second airtight gas channels that described purification chamber is connected with described sensor cavities.
3. formaldehyde tester according to claim 2, is characterized in that: described sensor cavities has an entrance gas channels, the entrance gas channels of described sensor cavities is provided with and described test gas circuit and the gas path switching device calibrated gas circuit and be connected.
4. formaldehyde tester according to claim 3, it is characterized in that: described gas path switching device has Chang Kaiduan and normal-closed end, described Chang Kaiduan is connected with described test gas circuit, described normal-closed end is connected with described calibration gas circuit.
5. formaldehyde tester according to claim 2, is characterized in that: described purification chamber includes multilayer acticarbon, and adjacent two layers is separately fixed on the relative sidewall of purification chamber two, is crisscross arranged to make the acticarbon in two opposing sidewalls.
6. formaldehyde tester according to claim 1, is characterized in that: the gas access place of described sensor cavities is provided with fair water fin.
7. formaldehyde tester according to claim 3, it is characterized in that: described signal acquisition process unit comprises the signal condition change-over circuit of setting parallel with one another, constant-current circuit and exciting circuit, one end of described conditioning change-over circuit, constant-current circuit and exciting circuit is connected with described microprocessor, and one end is connected with described sensor.
8. formaldehyde tester according to claim 1, is characterized in that: described formaldehyde tester also comprises the radio communication unit that one end is connected with described microprocessor, and described radio communication unit is bluetooth communication module or WiFi module.
9. formaldehyde tester according to claim 1, is characterized in that: described formaldehyde tester also comprises the power supply unit, storage unit, display unit and the alarm unit that are electrically connected with described microprocessor.
10. formaldehyde tester according to claim 7, is characterized in that: described exciting circuit, gas path switching device and extractor fan adopt independent voltage stabilizing to power.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201521074352.8U CN205210058U (en) | 2015-12-21 | 2015-12-21 | Formaldehyde tester |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201521074352.8U CN205210058U (en) | 2015-12-21 | 2015-12-21 | Formaldehyde tester |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN205210058U true CN205210058U (en) | 2016-05-04 |
Family
ID=55847767
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201521074352.8U Active CN205210058U (en) | 2015-12-21 | 2015-12-21 | Formaldehyde tester |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN205210058U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105606765A (en) * | 2015-12-21 | 2016-05-25 | 苏州纳格光电科技有限公司 | Formaldehyde tester |
| CN109946354A (en) * | 2019-04-03 | 2019-06-28 | 苏州市计量测试院 | Air formaldehyde distribution cloud monitors system and method |
-
2015
- 2015-12-21 CN CN201521074352.8U patent/CN205210058U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105606765A (en) * | 2015-12-21 | 2016-05-25 | 苏州纳格光电科技有限公司 | Formaldehyde tester |
| CN109946354A (en) * | 2019-04-03 | 2019-06-28 | 苏州市计量测试院 | Air formaldehyde distribution cloud monitors system and method |
| CN109946354B (en) * | 2019-04-03 | 2024-03-15 | 苏州市计量测试院 | Air formaldehyde distributed cloud monitoring system and method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104965009B (en) | A kind of Hydrogen Concentration Detector | |
| CN202230051U (en) | Handheld formaldehyde detector | |
| CN103424465B (en) | Intelligent PID sensor assembly | |
| CN102032951A (en) | Air quality detector | |
| CN102998622B (en) | The detection method of telepilot and cell voltage thereof and device | |
| CN205210058U (en) | Formaldehyde tester | |
| CN105606765A (en) | Formaldehyde tester | |
| CN102928254A (en) | Intelligent water sampler | |
| CN103105411A (en) | Self-calibration sterilizing gas concentration detection equipment based on wireless data transmission technology | |
| CN202693518U (en) | Dissolved oxygen monitoring system based on polarographic electrode | |
| CN211426409U (en) | Atmospheric environment monitoring system | |
| CN107817076A (en) | A kind of portable oxygen feed channel gas leakage detection, calibrating installation and method | |
| CN106768654A (en) | A kind of multifunctional gas quantitative leak detector | |
| CN209102473U (en) | A kind of sulfur hexafluoride sampling system | |
| CN208537087U (en) | A kind of wireless standard dynamometer for on-site test | |
| CN204596017U (en) | Remote-control intelligent mass rate gas meter, flow meter | |
| CN207851571U (en) | A kind of All-in-One sensor device | |
| CN206960301U (en) | A kind of environment measuring portable equipment | |
| CN208239385U (en) | A kind of monitoring modular for searching the source of atmospheric pollution | |
| CN203705069U (en) | Portable wireless thermometer | |
| CN107727709A (en) | A kind of portable automobile exhaust detection means | |
| CN108760982A (en) | A kind of portable air mass detecting instrument | |
| CN204740224U (en) | Formaldehyde detection apparatus | |
| CN212059824U (en) | Canister protection time detection device | |
| CN210128963U (en) | Self calibration volatile organic compound's measuring equipment |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |