CN107179315B - A kind of transformer oil moisture measurement test paper, preparation and application - Google Patents
A kind of transformer oil moisture measurement test paper, preparation and application Download PDFInfo
- Publication number
- CN107179315B CN107179315B CN201710560872.7A CN201710560872A CN107179315B CN 107179315 B CN107179315 B CN 107179315B CN 201710560872 A CN201710560872 A CN 201710560872A CN 107179315 B CN107179315 B CN 107179315B
- Authority
- CN
- China
- Prior art keywords
- test paper
- blue
- paper
- transformer oil
- developing agent
- 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
- 238000012360 testing method Methods 0.000 title claims abstract description 58
- 238000002360 preparation method Methods 0.000 title claims abstract description 8
- 238000005259 measurement Methods 0.000 title abstract description 13
- 229920002678 cellulose Polymers 0.000 claims abstract description 20
- 239000001913 cellulose Substances 0.000 claims abstract description 20
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 19
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 claims abstract description 18
- 238000000034 method Methods 0.000 claims abstract description 18
- 239000002253 acid Substances 0.000 claims abstract description 12
- ARUVKPQLZAKDPS-UHFFFAOYSA-L copper(II) sulfate Chemical compound [Cu+2].[O-][S+2]([O-])([O-])[O-] ARUVKPQLZAKDPS-UHFFFAOYSA-L 0.000 claims abstract description 12
- 239000003208 petroleum Substances 0.000 claims abstract description 10
- JGIATAMCQXIDNZ-UHFFFAOYSA-N calcium sulfide Chemical compound [Ca]=S JGIATAMCQXIDNZ-UHFFFAOYSA-N 0.000 claims abstract description 8
- 239000000835 fiber Substances 0.000 claims abstract description 5
- 239000011812 mixed powder Substances 0.000 claims abstract description 4
- 239000000203 mixture Substances 0.000 claims abstract description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 13
- 238000001035 drying Methods 0.000 claims description 10
- 238000001514 detection method Methods 0.000 claims description 7
- 238000007654 immersion Methods 0.000 claims description 5
- 239000004570 mortar (masonry) Substances 0.000 claims description 3
- 239000000843 powder Substances 0.000 claims description 3
- 239000003153 chemical reaction reagent Substances 0.000 claims description 2
- 238000003860 storage Methods 0.000 claims description 2
- 238000005303 weighing Methods 0.000 claims description 2
- 241001062009 Indigofera Species 0.000 claims 1
- 230000009466 transformation Effects 0.000 claims 1
- 238000002845 discoloration Methods 0.000 abstract description 6
- 238000004519 manufacturing process Methods 0.000 abstract description 3
- 238000002156 mixing Methods 0.000 abstract description 3
- 239000006185 dispersion Substances 0.000 abstract description 2
- 230000018109 developmental process Effects 0.000 description 5
- 230000035945 sensitivity Effects 0.000 description 5
- 238000002791 soaking Methods 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 3
- 229910000366 copper(II) sulfate Inorganic materials 0.000 description 3
- RWSOTUBLDIXVET-UHFFFAOYSA-N Dihydrogen sulfide Chemical compound S RWSOTUBLDIXVET-UHFFFAOYSA-N 0.000 description 2
- 238000004566 IR spectroscopy Methods 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 230000002378 acidificating effect Effects 0.000 description 2
- 230000015556 catabolic process Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 229910000037 hydrogen sulfide Inorganic materials 0.000 description 2
- AGVJBLHVMNHENQ-UHFFFAOYSA-N Calcium sulfide Chemical class [S-2].[Ca+2] AGVJBLHVMNHENQ-UHFFFAOYSA-N 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- VQLYBLABXAHUDN-UHFFFAOYSA-N bis(4-fluorophenyl)-methyl-(1,2,4-triazol-1-ylmethyl)silane;methyl n-(1h-benzimidazol-2-yl)carbamate Chemical compound C1=CC=C2NC(NC(=O)OC)=NC2=C1.C=1C=C(F)C=CC=1[Si](C=1C=CC(F)=CC=1)(C)CN1C=NC=N1 VQLYBLABXAHUDN-UHFFFAOYSA-N 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 229910052927 chalcanthite Inorganic materials 0.000 description 1
- 238000013329 compounding Methods 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 150000002170 ethers Chemical class 0.000 description 1
- 239000002657 fibrous material Substances 0.000 description 1
- 238000004817 gas chromatography Methods 0.000 description 1
- 239000004519 grease Substances 0.000 description 1
- XLYOFNOQVPJJNP-ZSJDYOACSA-N heavy water Substances [2H]O[2H] XLYOFNOQVPJJNP-ZSJDYOACSA-N 0.000 description 1
- 238000006703 hydration reaction Methods 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 238000002386 leaching Methods 0.000 description 1
- 239000003446 ligand Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000003595 spectral effect Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/75—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated
- G01N21/77—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated by observing the effect on a chemical indicator
- G01N21/78—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated by observing the effect on a chemical indicator producing a change of colour
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/75—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated
- G01N21/77—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated by observing the effect on a chemical indicator
- G01N2021/775—Indicator and selective membrane
Landscapes
- Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Plasma & Fusion (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)
- Housings And Mounting Of Transformers (AREA)
Abstract
The invention discloses a kind of transformer oil moisture measurement test paper, preparation and application, which is to be immersed in be prepared in color developing agent for carrier with the general fibre element scraps of paper (content of cellulose is in 99.1-99.6%).The composition of color developing agent are as follows: weigh 38-40% copper sulphate, 38-40% calcium sulfide according to mass percent in water-less environment, it is uniform to be dissolved in dispersion mixing in petroleum ether for the mixed-powder of 20-22% acid blue.Test paper of the present invention is light blue, the micro-moisture in transformer oil can delicately be detected, its colourshifting process are as follows: light blue → navy blue → blue-green → black-and-blue is navy blue when moisture content 20ppm, discoloration is obvious, validity period is long, it is easy to detect it is intuitive, production is simple, low in cost.
Description
Technical field
The present invention relates to a kind of quick, sensitive, convenient and fast transformer oil moisture measurement test paper, preparation and application, belonging to
Learn detection field.
Background technique
The larger electric property that can make transformer oil of Water Content in Transformer Oil degenerates, and can make breakdown voltage, insulated electro
Resistance decline, dielectric loss increase, the integral insulation level decline of electrical equipment.It can accelerate the degradation with aging of paper fiber material, especially
It is when containing more low molecular acid in oil, moisture more very, makes insulating paper by permanent destruction fiber Hydrolysis, because
This must strictly monitor the moisture content in transformer oil.
Currently without the test paper for detecting transformer oil moisture content, detecting the common method of transformer oil moisture has library
Human relations method, gas chromatography, infra-red sepectrometry etc., these detection methods, it is desirable that there is laboratory condition, and detection time is longer,
It operates loaded down with trivial details, costly, is unfavorable for field quick detection.Therefore, there is an urgent need to establish it is quick, convenient, can at the scene directly
Measure the method and its technological means of Water Content in Transformer Oil.
Summary of the invention
The purpose of the present invention is to provide a kind of quick, sensitive, convenient and fast transformer oil moisture measurement test paper, prepares and answer
With prepared test paper can detect moisture content at the scene, and discoloration is obvious, validity period is long, intuitive, production easy to detect
Simply, low in cost, early warning is provided for transformer fault.
Realizing the technical solution of above-mentioned purpose is:
The present invention provides a kind of transformer oil moisture content test paper, described is the leaching using the general fibre element scraps of paper as carrier
What bubble was prepared in color developing agent；The preparation of the color developing agent is to weigh 38-40% in water-less environment with mass percent
Copper sulphate, 38-40% calcium sulfide, the mixture of 20-22% acid blue grind into powdered and drying to constant weight, are then dissolved in
Dispersion mixing is uniform in petroleum ether.
Further, the carrier is the cellulose scraps of paper of the content of cellulose in 99.1-99.6%.
Further, the test paper length is 8-10 centimetres, and width is 0.5-1 centimetres.
Further, it is analytical reagents that color developing agent, which prepares copper sulphate, calcium sulfide, acid blue and petroleum ether used,.
Further, the soaking process be the cellulose scraps of paper are put into time for being impregnated in color developing agent be 24 hours and with
On.
Further, it is spare to be put into storage in drier for the cellulose scraps of paper after the immersion.
The preparation method of transformer oil moisture measurement test paper of the present invention carries out as steps described below:
Step 1: weighing mass percent 38-40% copper sulphate, 38-40% calcium sulfide, the mixing of 20-22% acid blue
Object is placed in mortar and is ground into powder, is put into baking oven that drying to constant weight at temperature, to remove moisture.After drying
Mixed-powder, which is dissolved in being stirred continuously in petroleum ether, to be uniformly dispersed, and impregnates 24 hours and color developing agent derived above.
It dries Step 2: the cellulose scraps of paper are put into baking oven, to remove moisture, the cellulose scraps of paper after drying is put into
Impregnated in color developing agent petroleum ether, the cellulose scraps of paper after immersion are put into drier store it is spare.
The present invention also provides the detections of above-mentioned test paper to judge that the moisture content in transformer oil, the method are as follows:
Transformer oil is drawn with dropper, about 5 milliliters of transformer oil are added dropwise on test paper, when the moisture in transformer oil
For content when 10-20mg/L test paper color development is light blue, when the moisture content in oil is greater than 20mg/L, test paper color development is dark blue
Color.
Test paper prepared by the present invention be it is light blue, with the increase of Water Content in Transformer Oil, test paper discoloration
Process are as follows: light blue → navy blue → blue-green → black-and-blue.
The principle of the present invention are as follows: be the hydration reaction of copper sulphate first, generate the cupric sulfate pentahydrate of blue.Acid blue is readily soluble
Solution is blue in hot water or cold water, will become navy blue under acidic environment, big compared to cupric sulfate pentahydrate colour developing area, when continuing
Between it is long, change colour in visible-range sensitiveer.Calcium sulfide is reacted with water can generate hydrogen sulfide, form acidic environment, greatly
Improve the sensitivity of acid blue discoloration.The compounding reaction of these three substances not only increases the stability of color development system, is formed
Ligand with bigger conjugated system, with bigger spectral absorption capacity and effectively add lustre to area, and its mole
Absorptivity is big, and reaction sensitivity and selectivity are high.
Reaction equation is as follows:
CuSO4+5H2O=CuSO4·5H2O
CaS+2H2O=Ca (OH)2+H2S
Acid blue C45H44N2NaO7S2Structural formula it is as follows:
It may determine that the moisture content in transformer oil using above-mentioned transformer oil moisture measurement test paper, method is such as
Under:
Transformer oil is drawn with dropper, about 5 milliliters of transformer oil are added dropwise on test paper, when the moisture in transformer oil
Content is when 10-20mg/L test paper color development is light blue, when the moisture content in oil is greater than 20mg/L.Test paper color development is dark blue
Color.
The utility model has the advantages that
(1) basis material that the present invention uses is the general fibre element scraps of paper, easy to make, low in cost.
(2) moisture measurement test paper is especially sensitive to micro-moisture in oil in transformer oil of the invention, passes through color change
The depth reflect the size of water content in oil content, intuitive and convenient.
(3) test paper is light blue, with the increase of Water Content in Transformer Oil, test paper colourshifting process are as follows: light blue
Color → navy blue → blue-green → black-and-blue discoloration is significant and easy to identify, validity period is long, it is easy to detect it is intuitive, production is simple, at
This is cheap.
Detailed description of the invention
Fig. 1 is the infrared spectroscopy structure chart of transformer oil moisture measurement test paper.
Fig. 2 is transformer oil moisture measurement test paper colourshifting process figure.
Specific embodiment
In order to better understand and implement, by specific embodiment, the present invention will be described in detail, but does not limit the present invention.
Embodiment 1: transformer oil moisture measurement test paper is prepared by a method comprising the following steps::
Step 1: 9 grams of copper sulphate, 9 grams of calcium sulfides and 5 grams of acid blues are weighed, is placed in mortar and is ground into powder, put
Enter in baking oven and dries at a temperature of 80 DEG C to constant weight, to remove moisture.Mixed-powder after drying is put into 200 milliliters of petroleum ethers
In be stirred continuously and be uniformly dispersed, obtain color developing agent.
Step 2: it is 8 centimetres that the cellulose scraps of paper, which are cut into length, and the scraps of paper that width is 1 centimetre are put into baking oven at 80 DEG C
At a temperature of dry to constant weight, to remove moisture.
Step 3: the cellulose scraps of paper after drying being put into color developing agent and are impregnated 24 hours or more, and soaking time is short aobvious
Toner cannot be sufficiently submerged in the cellulose scraps of paper, the cellulose scraps of paper after immersion are put into drier store it is spare.
The test paper prepared is detected through infrared spectroscopy, is had in the region 1360-1000cm-1 as shown in Figure 1: very strong
Absorption peak and peak shape is sharp, is the characteristic peak of C-N- base, shows that color developing agent has been immersed on the scraps of paper.
The measuring method of transformer oil moisture: drawing transformer oil with dropper, and about 5 milliliters of transformer oil are added dropwise and try in test
On paper, then compare the variation of test paper color.
It should be noted that above-described embodiment is highly preferred embodiment of the invention, it is not intended to limit protection model of the invention
It encloses.Embodiment 2: the judgement of test paper sensitivity
The cellulose scraps of paper prepared in embodiment 1 are immersed in color developing agent, transformer oil is drawn with dropper, is added dropwise about 5
On the test paper of different soaking times, the variation for then comparing test paper color see the table below milliliter transformer oil:
As it can be seen that the sensitivity of test paper and soaking time have very big relationship, when soaking time reach 24 it is small when more than, test paper
With better sensitivity.
Embodiment 3: the transformer oil result of measurement different in moisture content compares
Laboratory using micro-water analyzer according to " GB/T 7600-2014 operation in transformer oil and steam turbine grease
Point content determination (coulomb method) " the different transformer oil of detection moisture content, with the change of test paper test different in moisture content
Depressor oil, testing result are as follows:
With the increase of Water Content in Transformer Oil, as shown in Fig. 2, test paper color colourshifting process are as follows: light blue → deep
Blue → blue-green → black-and-blue changes colour significant and easy to identify.Due to dry transformer oil moisture measurement test paper be it is light blue,
Test paper aobvious navy blue when detecting the transformer oil of water content 20ppm, colour developing is most obvious and stablizes, therefore water content 20ppm is
The critical value of test paper discoloration.
Claims (9)
1. a kind of transformer oil moisture content test paper, it is characterised in that: using the general fibre element scraps of paper as carrier, be immersed in color developing agent
In be prepared；The preparation of the color developing agent is to weigh 38-40% copper sulphate, 38- in water-less environment with mass percent
40% calcium sulfide, the mixture of 20-22% acid blue grind into powdered and drying to constant weight, are then dissolved in petroleum ether and divide
It dissipates and is uniformly mixed.
2. test paper according to claim 1, it is characterised in that: the carrier is content of cellulose in 99.1-
The 99.6% cellulose scraps of paper.
3. test paper according to claim 1, it is characterised in that: the test paper length is 8-10 centimetres, and width is
0.5-1 centimetres.
4. test paper according to claim 1, it is characterised in that: color developing agent prepares copper sulphate used, calcium sulfide, acid
Property indigo plant and petroleum ether are analytical reagents.
5. test paper according to claim 1, it is characterised in that: the carrier be immersed in the process in color developing agent be by
It is 24 hours or more that the cellulose scraps of paper, which are put into time for impregnating in color developing agent,.
6. test paper according to claim 1, it is characterised in that: the cellulose scraps of paper after the immersion are put into drier
Interior storage is spare.
7. the preparation method of any test paper of claim 1~6, which comprises the following steps:
Step 1: weighing mass percent 38-40% copper sulphate, 38-40% calcium sulfide, the mixture of 20-22% acid blue is set
Powder is ground into mortar, is put into baking oven that drying to constant weight, and to remove moisture, the mixed-powder after drying is dissolved in
It is stirred continuously and is uniformly dispersed in petroleum ether, impregnate 24 hours and color developing agent derived above；
It is dried Step 2: the cellulose scraps of paper are put into baking oven, to remove moisture, the cellulose scraps of paper after drying is put into colour developing
Impregnated in agent petroleum ether, the cellulose scraps of paper after immersion are put into drier store it is spare.
8. the application of any test paper of claim 1~6, which is characterized in that application test paper detection is sentenced
Moisture content in disconnected transformer oil, the method for detecting judgement are as follows:
Transformer oil is drawn with dropper, about 5 milliliters of transformer oil are added dropwise on test paper, when the moisture content in transformer oil
When 10-20mg/L test paper color development is light blue, when the moisture content in oil is greater than 20mg/L, test paper color development is navy blue.
9. the application of test paper according to claim 8, it is characterised in that: the test paper be it is light blue, with transformation
The increase of device water content in oil content, test paper colourshifting process are as follows: light blue → navy blue → blue-green → black-and-blue.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710560872.7A CN107179315B (en) | 2017-07-11 | 2017-07-11 | A kind of transformer oil moisture measurement test paper, preparation and application |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710560872.7A CN107179315B (en) | 2017-07-11 | 2017-07-11 | A kind of transformer oil moisture measurement test paper, preparation and application |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107179315A CN107179315A (en) | 2017-09-19 |
| CN107179315B true CN107179315B (en) | 2019-08-20 |
Family
ID=59844805
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710560872.7A Active CN107179315B (en) | 2017-07-11 | 2017-07-11 | A kind of transformer oil moisture measurement test paper, preparation and application |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107179315B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109283165B (en) * | 2018-10-31 | 2020-11-06 | 曲阜师范大学 | Preparation method and application of fluorescent test strip for analyzing trace water in organic reagent |
| CN113640284B (en) * | 2021-09-06 | 2022-11-11 | 武汉理工大学 | Method and device for rapidly detecting nickel ions |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1740781A (en) * | 2005-09-18 | 2006-03-01 | 青岛海洋化工有限公司 | Novel blue variable colour indicator agent and producing process thereof |
| CN203396707U (en) * | 2013-08-13 | 2014-01-15 | 中国南方航空工业(集团)有限公司 | Test paper for detecting moisture in fuel oil |
-
2017
- 2017-07-11 CN CN201710560872.7A patent/CN107179315B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1740781A (en) * | 2005-09-18 | 2006-03-01 | 青岛海洋化工有限公司 | Novel blue variable colour indicator agent and producing process thereof |
| CN203396707U (en) * | 2013-08-13 | 2014-01-15 | 中国南方航空工业(集团)有限公司 | Test paper for detecting moisture in fuel oil |
Non-Patent Citations (2)
| Title |
|---|
| Determination of Water Content in Transformer Insulation;A. Shkolnik等;《International Conference on Dielectric Liquids》;20020712;第337-340页 |
| 基于变压器油的微水在线测量传感器的研制;唐德东等;《计量技术》;20051231;第8-10页 |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107179315A (en) | 2017-09-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107179315B (en) | A kind of transformer oil moisture measurement test paper, preparation and application | |
| Abderrazzaq et al. | Impact of multi-filtration process on the properties of olive oil as a liquid dielectric | |
| CN103149309A (en) | Measuring method for the furfural content of transformer oil | |
| CN104502298B (en) | A kind of measure cadmium and the method for micro lead in iron ore | |
| CN103245660B (en) | A kind of edible oil and fat determination of POV composite reagent and detection method | |
| CN106905537A (en) | The synthetic method of the metal-organic framework material with fluorescence property and its application | |
| Peng et al. | Indirect detection of DP for insulating paper based on methanol content in transformer oil by spectroscopic approach | |
| CN107894444A (en) | A kind of Oil-Paper Insulation moisture content fitting algorithm | |
| CN101881731B (en) | Fast detection method of benzo(a) pyrene in high-fat foods | |
| Kimuro et al. | Thermodynamic study of the complexation of humic acid by calorimetry | |
| CN106248609B (en) | A kind of method that ultraviolet specrophotometer measures hexafluorophosphoric acid lithium content in lithium-ion battery electrolytes | |
| CN101893576A (en) | Heavy metal detection test paper and preparation method and application thereof | |
| CN103245553A (en) | Environment-friendly high-efficiency acid reflux collection-type element analysis sample digestion method | |
| CN107966347B (en) | Extract liquid for soluble matters of waterproof coiled material and application thereof | |
| von Steinkirch Souza et al. | Evaluation of the chemical stability of methanol generated during paper degradation in power transformers | |
| CN105954242A (en) | Rhodamine derivative-based polymer sample and application thereof in water content analysis | |
| CN106908509A (en) | The quick and quantitative detecting method of doping paraffin in a kind of lard | |
| Senila et al. | Validation of a method for determination of free glycerol in biodiesel | |
| CN109283165B (en) | Preparation method and application of fluorescent test strip for analyzing trace water in organic reagent | |
| CN102507465A (en) | Novel turmeric direct photometry for determining boron content in steel | |
| Hunt et al. | A modified field test for the determination of carbon disulphide vapour in air | |
| CN111272684B (en) | Fe in electrolyte 2+ Method for measuring concentration | |
| Dixit et al. | Applicability of Methanol as a Solid Insulation Ageing Indicator in Retrofilled Transformers | |
| CN104764633B (en) | Chemical sample preparation method for testing heavy metal content in soil and sewage | |
| CN109425674A (en) | It is a kind of for detecting the tracer of recycled wood materials |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |