Some standard content:
GB/T4070—1996
This standard is a revision of GB4070~GB4072—83. As there is no international standard for phosphors, the corresponding phosphor test methods of foreign companies were referred to during the revision. This standard makes the following revisions to the original standards GB4070~GB4072-83: The original three standards are merged into one standard; The original standard formulates the test methods according to the phosphor category, and the test methods of various types of phosphors are mostly the same, except for a few different performance test methods, which makes the content of the standard repeated. During the revision, the test methods are compiled according to performance parameters instead of categories to avoid duplication. The applicability of specific test methods is explained in Chapter 1 of this standard; The backward test methods in the original standard are abolished in this standard text, and the more advanced test methods widely used are added. In order to take into account the advancement and practicality of the test methods, for some performance parameters, this standard text recommends several methods at the same time, but stipulates an arbitration test method.
This standard shall replace GB4070~4072-83 from the date of implementation. This standard is proposed by the Ministry of Electronics Industry of the People's Republic of China. This standard is under the jurisdiction of the Standardization Institute of the Ministry of Electronics Industry. The drafting units of this standard are the Standardization Institute of the Ministry of Electronics Industry and Beijing Chemical Plant. The main drafters of this standard are Liu Yun, Zhu Linsheng, Sun Tiejing, Zhou Yuanbiao, and Cao Wei. 1 Scope
National Standard of the People's Republic of China
Test methods for properties of phosphers
Test methods for properties of phosphersGB/T 4070-1996
Replaces GB4070~4072-83
This standard specifies the test methods for water-soluble chloride, density, particle size distribution, relative brightness, relative spectral power distribution, chromaticity coordinates, ultraviolet radiation stability, afterglow relative brightness, relative photometric efficiency, afterglow time, thermal stability, and dry and mixed adhesion of phosphors. This standard applies to all kinds of fluorescent powders, among which the test methods for ultraviolet radiation stability and afterglow relative brightness are only applicable to photoluminescent fluorescent powders, and the test methods for lumen efficiency, afterglow time, thermal stability, dryness and adhesion are only applicable to cathode ray ignition fluorescent powders. 2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised. Parties using this standard should explore the possibility of using the latest versions of the following standards. GB 602-88 Preparation of standard solutions for determination of impurities in chemical reagents CB603-88 Preparation of preparations and products used in test methods for chemical reagents GB5838--86 Phosphor terminology
3 Definitions
3.1 Afterglow relative brightness
The ratio of the brightness of the sample to the same brand of standard sample within a specified time after the excitation of the phosphor stops is called afterglow relative brightness. 3.2 Other terms
Other terms used in this standard shall be in accordance with GB 5838. 4 Determination of water-soluble oxides
4.1 Principle
In nitric acid medium, chloride ions and silver ions form insoluble silver chloride precipitation. When the oxygen ion content is low, silver chloride is suspended in a certain period of time, making the solution turbid, thereby performing turbidimetric determination of fluoride. 4.2 Reagents and solutions
4.2.1 Zinc sulfate solution (50g/L)
Weigh 5.0g zinc sulfate, dissolve in water, dilute to 100ml, and shake. 4.2.2 Phosphoric acid (25%)
Prepare in accordance with the provisions of GB603.
4.2.3 Silver nitrate solution (17g/L)
Prepare in accordance with the provisions of CB603.
4.2.4 Chloride standard solution
Prepare according to the provisions of GB602.
Approved by the State Administration of Technical Supervision on September 9, 1996 and implemented on May 1, 1997
4.3 Determination steps
GB/T 4070.-. 1996
4.3. 1 Weigh 2.0 sample, put it into a beaker, add 20 mL of water and 1~2 drops of zinc sulfate solution, heat to boiling, and then cool to room temperature.
4.3.2 Filter with qualitative filter paper, put the filtrate into a colorimetric tube, and wash the filter residue with a small amount of hot water 2~3 times, and dilute with water at a rate of 25mL. 4.3.3 Add 0.5mL of 25% silver nitrate solution and shake well, let it stand for 10 minutes, and the turbidity should not be greater than that of chloride standard solution. 4.3.4 Test the standard sample in parallel with the sample.
4.3.5 Test results
Compare the test results of the standard sample with those of the test sample. 5 Density determination
5.1 Principle
At the same temperature, measure the mass of water filling the same density bottle respectively. The mass of water can determine the volume of the density bottle, i.e. the volume of the sample. The density can be calculated based on the mass and volume of the sample. 5.2 Instruments
5-2.1 Analytical balance: nominal value 0.001g. 5.2.2 Thermometer; the graduation value should not be greater than 0. 5℃. 5.2.3 Degree bottle; the capacity is 25mL
5.3 Determination steps
5.3.1 Put 3g~5g of dry sample into the density bottle and weigh it with a large balance. 5.3.2 Fill the density bottle with 2/3 of its volume of water, remove the bubbles, and then fill it with water until it is full. Wipe the outer surface of the bottle and weigh it with a balance. 5.3.3 Measure the water temperature in the bottle with a thermometer.
5.3.4 Pour out the liquid to be tested from the density bottle and clean it. Fill the density bottle with water of the same temperature, wipe the outer surface of the bottle and weigh it with a balance. 5-4 Calculation of analysis results
The density of the phosphor is calculated according to formula (1).
Pi- (m, - m3-(m, - ma) * Pe
Where: P—density of phosphor·g/cm\; P—density of water at tC, g/cm;
1—mass of density bottle+8
m2 total mass of density bottle plus sample;
m-total mass of density bottle plus sample and then filled with water, gm total mass of density bottle filled with water, g. 5.5 Tolerance and results
Calculation results shall be rounded to two decimal places. Each sample shall be tested twice according to the determination steps. The difference between parallel results shall not be greater than 0.02. The arithmetic mean of the two test results shall be taken. ||tt| |6 Determination of particle size distribution
6.1 Coulter method (arbitration method)
6.1.1 Principle
Particles suspended in electrolyte enter the small hole under the action of reduced pressure. There is an electrode inside and outside the small hole tube. When the particles enter the small tube, each particle will replace the electrolyte with an equal volume, and the change in resistance between the two electrodes caused by the rain is converted into an electric pulse change. The pulse amplitude is proportional to the particle size, and the number of pulses is proportional to the number of particles. After data processing, the particle size distribution curve is drawn. 6.1.2 Instrument
GB/T 4070--1996
Coulter particle size analyzer, measurement range: 0.4 μm~200 μm6.1.3 Determination steps
According to the requirements of the product technical standards and the provisions of the instrument, take an appropriate amount of sample for dispersion treatment, then measure and draw its particle size distribution curve, and calculate the central particle size and average particle size. 6.2 Other aspects
The particle size of phosphor can also be measured by other methods such as sedimentation method and observation method. 7 Determination of relative brightness
7.1 Principle
Phosphor emits visible light under specified excitation conditions, which is converted into photocurrent or photovoltage by a photodetector, and this value is recorded and compared with the photocurrent or photovoltage value of the standard powder measured by the same method to obtain the relative brightness of the sample. 7.2 Apparatus
7.2.1 Apparatus for measuring brightness of photoluminescent powder7.2.1.1 Ultraviolet excitation instrument
253.7mm or 365. 0nm ultraviolet auxiliary low-pressure mercury lamp, power of 4W~~20W, equipped with a filter with a transmittance of no more than 0.1% in the wavelength range of 380mm~760nm.
7.2.1.2 Photodetector
Its performance indicators meet the requirements of the national first-level illuminance meter for photodetectors. 7.2.1.3 Schematic diagram of the stomach loading principle
Excitation light source
Filter
Sample stagewwW.bzxz.Net
Photodetector
Figure 1 Schematic diagram of the principle of the photoluminescent powder relative brightness measurement device 7.2.2 Cathode ray induced phosphor relative brightness measurement device 7.2.2.1 Cathode ray excitation instrument: The stability of the electron beam current is better than 1×10-3/30min. 7.2-2.2 Photodetector: Its performance indicators meet the requirements of the national first-level illuminance meter for detectors. 7.2.2.3 The schematic diagram of the device principle is shown in Figure 1. 7.3 Measurement steps
7.3.1 Place the sample and standard sample in a metal sample pan at the same time, and flatten the surface with a flat glass. The standard sample can only be used once. 7.3.2 Excite the sample and standard sample according to the product technical standards. 7.3.3 Use a photoelectric detector to convert the light emitted by the sample and the same brand of standard sample into photocurrent (or photovoltage), and record this value. Repeat the reading three times for each sample and standard sample. The relative error should not exceed 2%. Take the arithmetic mean for calculation. 7.4 Calculation of analysis results
The relative brightness of the sample is calculated according to formula (2) or (3): ×100%
×100%
Where: L—relative brightness of the sample, %;
I——photocurrent value of the sample, mA;
T——photocurrent value of the same brand of standard sample, mA; V—photovoltage value of the sample, mV;
GB/T 4070—1996
V. — Photoelectric value of the same brand of standard sample, mV7.5 tolerance
The difference in analysis results between laboratories should not be less than 2%. 8 Determination of relative spectral power distribution
8.1 Principle
Under the specified excitation conditions, the radiation power of the phosphor is distributed according to the wavelength. The photocurrent value at the specified interval wavelength is recorded by the spectrometer and the photodetector. After system correction and normalization, the relative spectral power distribution curve can be obtained. 8.2 Apparatus
8.2.1 Spectrophotometer
8.2.1.1 Calibration of the wavelength reading and the corresponding relationship between the spectrometer wavelength: Use a light source with a known wavelength (such as a mercury lamp or a sodium lamp) to calibrate the corresponding relationship between the spectrometer's emission wavelength and the instrument's wavelength reading. 8.2.1.2 Calibration of the test system's spectral response Use a standard diffuse reflection white board. Place it on the sample position, and under the condition that the output signal of the photomultiplier tube is sufficient, use a 2856K distributed temperature standard lamp to illuminate the standard reflective white board, so that the incident slit and the exit slit meet the bandwidth requirements, record the output light signal response value at the specified wavelength interval, and calculate it according to formula (4): a(a) = So() - Pe(u)
Where: a(a)-—the inverse of system sensitivity; -relative spectral power of the 2856K distributed temperature standard lamp; S,)
-spectral reflectivity of the standard diffuse reflective white board; I(a)——light signal response value.
Draw the relationship curve between α() and ^.
8.2.2 Excitation instrument
Requirements are the same as those in 7.2.1.1 or 7.2.2.1.8.2-3 Schematic diagram of device source
Excitation source
Sample stage
Spectrophotometer
Figure 2 Schematic diagram of relative spectral power distribution measurement device8.3 Measurement steps
8.3.1 Same as 7.3.1.
8.3.2 Same as 7.3.2.
8.3.3 After the sample is stably excited, the spectrophotometer measures the light signal response value at the specified room wavelength interval. 8.4 Calculation of analysis results
The relative spectral power is calculated according to formula (5):
S(A) = I(d) +α(A)
Where: S(1) is the relative spectral power of the sample; I(1) is the light signal response value of the sample; α(1) is the reciprocal of the system sensitivity.
Take the maximum value as 100, normalize the other values, and draw the relative spectral power distribution curve of the sample. The above test and calculation can also be completed using multi-channel spectra. (4)
...-(5)
9 Determination of chromaticity coordinates
9.1 Apparatus
GB/T 4070—1996
9.1.1 Colorimeter: calibrated with a 2 856K distributed temperature standard lamp. 9.1.2 Spectrophotometer: requirements are the same as 8.2.1. 9.1.3 Excitation instrument: requirements are still 7.2.1.1 or 7.2.2.1 9.1.4 Photodetector: requirements are the same as 7.2.1.2. 9.2 Measurement steps
9-2.1 Spectrophotometry (arbitration method)
9.2.1.1 Measurement steps
Measurement steps are the same as 8.3. According to the requirements of the product technical standards, use a constant power of 253.7nm or 365.0nm ultraviolet light to stably excite the sample and measure its relative spectral power distribution curve (see 8.3). When measuring the line spectrum, the exit slit can be adjusted appropriately. 9.2.1.2 Calculation of analysis results
The tristimulus values are calculated according to formula (6), (7), (8), (9) respectively: X=I
2a)-z(a) Ad
Y=(a) +j() .
In the formula: X, Y, Z--tristimulus values
K--constant (normalization coefficient);
S(a)--relative spectral power:
P)-(A)-
Es()-() .A
(a)-color stimulus function, because the phosphor is a spontaneous color source, so g(a)=S(a) three (a), (A), yuan (1)-spectral distimulus value (see CIE 1931 2 ° viewing angle spectral tristimulus value) Wavelength interval (broad spectrum takes 10nm, line spectrum takes 1nm). The chromaticity scale is derived from the three stimulus values according to formulas (10), (11), and (12): X=X+Y+z
y=X+Y+z
X+￥+Z
Because + 3 + &=1, only is used to represent the chromaticity coordinates. The above tests and calculations can also be completed using a multi-channel spectrometer. 9.2.2 Colorimeter determination method (recommended method) - (7)
(19)
According to the provisions of 7.3.1 and 7.3.2, point the colorimeter light measuring head to the luminous surface of the sample, and directly read the chromaticity CB/T 4070-1996
coordinate value of the sample at the output end of the colorimeter, or read the X, Y, z three stimulus values, and calculate the chromaticity coordinates according to 9.2.1.2 +3. 9.3 The difference between the chromaticity coordinate elements and the measurement results of the difference
experimental cases should not exceed 0.002. 10 Determination of ultraviolet radiation stability of photoluminescent powder According to the requirements of the product technical standards, place the sample in an environment with specified temperature and relative humidity and maintain it for a certain time. Then place it under ultraviolet light of 2537nm or 3650nm for a certain period of time, and measure the relative brightness with the unirradiated samples of the same batch (as standard samples) according to the provisions of Chapter 7. The result shall not be lower than the requirements of the product technical standards. Then observe the body color under the same conditions, and the body color is not allowed to change. 11 Determination of relative brightness of afterglow of photoluminescent powder 11.1 Principle
The phosphor emits visible light under the excitation of ultraviolet radiation under specified conditions. When its brightness reaches saturation, stop the excitation and start timing. When the time specified by the product technical indicators is reached, measure the afterglow brightness and compare it with the brightness of the same brand standard sample to obtain the relative brightness of the afterglow. 11.2 Apparatus
Same as 7.2.1.
11.3 Determination steps
11.3.1Same as 7.3.1.
11.3.2Same as 7.3. 2.
11.3.3 When the brightness of the sample reaches saturation, stop emitting and timing. After the time specified by the product technical indicators is reached, use a photoelectric detector to measure the afterglow brightness of the standard sample and the sample, and record this value. 11.3.4 Calculation of analysis results
The relative brightness of the afterglow of the sample is calculated according to formula (13): ×100%
Where: L—relative brightness of the afterglow of the sample; I——light signal response value of the sample
I,——light signal response value of the standard sample.
12 Determination of lumen efficiency of cathode ray induced phosphor 12.1 Principle
Phosphor emits visible light under the excitation of an electron beam under specified conditions, which is converted into a light signal response value by a photoelectric detector. This value is recorded and compared with the light signal response value of the standard sample powder measured by the same method to obtain the lumen efficiency of the sample. 12.2 Apparatus
Same as 7.2.2.
12.3 Determination steps
Same as 7.3.
12.4 Calculation of analysis results
The lumen efficiency of the sample is calculated according to formula (14): = ×
Where: — lumen efficiency of the sample, 1 m/W; %—— lumen efficiency of the standard sample, 1 m/W;
I——light signal response value of the sample, mA; (14)
I—light signal response value of the standard sample, mA.
12.5 Difference
GB/T 4070—1996
The difference in analysis results between laboratories should not exceed 2%. 13 Determination of afterglow time of cathode ray induced phosphor 13.1 Apparatus
13.1.1 Square wave signal generator: The maximum amplitude of the square wave signal is required to be sufficient to stop the electron beam from exciting the sample. The width of the square wave should ensure that the afterglow decay process of the sample is complete, and the square wave front should be less than 1/10 of the afterglow time. 13.1.2 Photomultiplier tube: It is required to have sufficient spectral sensitivity in the visible spectrum, small dark current, high integral sensitivity, and should work in the linear region of light flow and photocurrent. When measuring afterglow, the load resistance and distributed capacitance should be selected so that the time constant RC of the cathode circuit is less than 1/10 of the afterglow time of the sample.
13.1.3 Oscilloscope: It is required to have appropriate bandwidth, gain and scanning speed. 13.1.4 Cathode ray excitation instrument: The stability of the electron beam current is required to be better than 1×10-\/30min. 13.1.5 Photodetector: Its performance indicators meet the requirements of the national first-level illuminance meter for photodetectors. 13.1.6 Device schematic diagram
Device schematic diagram Figure 3.
Square wave generator
Deflection plate
Sample plate
Optical tower tube
Oscilloscope
Figure 3 Schematic diagram of the device for measuring the afterglow time of cathode ray-induced phosphor 13.2 Measurement steps
13. 2. 1 Same as 7. 3, 1,
13.2.2 Stably excite the sample according to the voltage and current specified in the product technical standards. 13.2.3 Add the square wave signal to the modulation pole or deflection plate of the electron gun to periodically cut off or deflect the electron beam, and periodically generate a non-moving light spot on the sample.
13.2.4 Use a photomultiplier tube to convert the optical signal into an electrical signal, input it into an oscilloscope, adjust the delay circuit, and determine the afterglow time according to the time-scale signal of the oscilloscope by using the diurnal method or the photographic method. Or use a storage oscilloscope to measure, use a recorder or plotter to directly draw the afterglow curve and obtain the afterglow time.
14 Determination of thermal stability of cathode ray emitting phosphor 14.1 Apparatus
14.1.1 High temperature furnace.
14.1.2 Quartz crucible: 50mL.
14.1.3 Cathode ray emitting device: requirements are the same as 7.2.2.1. 14.1.4 Photoelectric detector requirements are the same as 7.2.2.214.1.5 Schematic diagram of the device: same as 7.2.1.3, 14.1.6 Colorimeter: requirements are the same as 9.1.1.
14.1.7 Spectrophotometer: requirements are the same as 8.2.1. GB/T 4070—1996
14.1.8 Excitation instrument requirements are the same as 7.2.1.1 or 7.2.2.1.14.1.9 Photoelectric detector: requirements are the same as 7.2.1.2.14.2 Determination steps
14.2.1 Take 10g of sample, put it in quartz, heat it in a high-temperature furnace at 450℃±10℃ for 1h, take it out and put it at room temperature, and measure the relative brightness with the same batch of samples that have not been heated (as standard samples) according to 7.3. The result should not be lower than the requirements of the product technical standard. 14.2.2 According to 9.2, measure the chromaticity coordinate values respectively, and the difference (change value) between the corresponding values should meet the requirements of the product technical standard.
15 Determination of wet adhesion of cathode ray fluorescent powder 15.1 Principle
Under the impact of a water column with a certain pressure and a certain flow rate, the H nozzle is kept vertical to the sample, the distance is equal, and the impact time is the same. The wet adhesion is inversely proportional to the size of the circular notch on the sample. 15.2 Reagents and materials
a) Standard fluorescent powder;
b) Test mixed fluorescent powder,
c) Potassium silicate +
d) Strontium nitrate,
e) Glass sheet;
f) Pure water.
15.3 Schematic diagram of the device
The schematic diagram of the device is shown in Figure 1.
Solenoid valve
High-level water tower
Figure 4 Schematic diagram of the wet adhesion test device for blocking ray-induced phosphor 15.4 Test steps
15.4.1 Simultaneously immerse the sample and standard sample in the selected process conditions and make a film. Test immediately after making the film. 15.4.2 Insert the nozzle of the test device into the precipitation liquid of the standard film, 1cm to 5cm away from the top of the standard sample. 15.4.3 Open the solenoid valve, and use a water column of a certain pressure to impact for several seconds according to the requirements of the product technical standards, and close the valve. 15.4.4 Measure the maximum and minimum diameters of the circular notch opened by the phosphor on the standard sample, and take the average value. GB/T 4070—1996
15.4.5 Measure the average diameter of the notch of the sample piece in the same way, and do three tests at the same time for the sample piece and the standard piece. 15.4.6 Take the arithmetic mean of the three tests, and compare the average diameters of the two notches. The sample piece should not be larger than the standard piece. 16 Determination of dry adhesion of cathode ray phosphor 16.1 Principle
The pressure at which the powder layer on the sample is notched under the impact of a water column is proportional to the dry adhesion. 16.2 Materials
a) Standard phosphor:
b) Test phosphor;
c) Potassium silicate,
d) Strontium nitrate:
e) Glass sheet:
f) Pure water.
16.3 Schematic diagram of the device
The schematic diagram of the device is shown in Figure 5.
Pressure gauge
Trace gas valve
Figure 5 Schematic diagram of the device for determining the dry adhesion of cathode ray phosphor 16.4 Test steps
16.4.1 Simultaneously, the sample and the standard sample are precipitated and prepared according to the selected F process conditions. After the preparation is completed, the precipitate is taken out and dried. 16.4.2 Place the standard sample into the measuring device and open the air inlet pressure control valve. 16.4.3 Increase the pressure of the water column at a certain rate according to the requirements of the product technical standards. Record the pressure of the water column at the moment when a gap appears in the powder layer on the standard sample.
16.4.4 Measure the water column pressure of the test piece in the same way. 16.5 Calculation of analysis results
Test the test piece and the standard sample at the same time and take the arithmetic mean. 16.6 Tolerance
Comparing the two water column pressures, the test piece should not be smaller than the standard sample.Determine the chromaticity coordinates respectively, and the difference (change value) between the corresponding values shall meet the requirements of the product technical standards.
15 Determination of wet adhesion of cathode ray induced phosphor 15.1 Principle
Under the impact of a water column with a certain pressure and a certain flow rate, the H nozzle is kept vertical to the sample, with an equal distance, and the same impact time is used. The wet adhesion is inversely proportional to the size of the circular notch on the sample where the phosphor is washed away. 15.2 Reagents and materials
a) Standard phosphor;
b) Test mixed phosphor,
c) Potassium silicate +
d) Strontium nitrate,
e) Glass sheet;
f) Pure water.
15.3 Schematic diagram of the device
The schematic diagram of the device is shown in Figure 1.
Solenoid valve
High-level water tower
Figure 4 Schematic diagram of the wet adhesion test device for blocking ray-induced phosphor 15.4 Test steps
15.4.1 Simultaneously immerse the sample and standard sample in the selected process conditions and make a film. Test immediately after making the film. 15.4.2 Insert the nozzle of the test device into the precipitation liquid of the standard film, 1cm to 5cm away from the top of the standard sample. 15.4.3 Open the solenoid valve, and use a water column of a certain pressure to impact for several seconds according to the requirements of the product technical standards, and close the valve. 15.4.4 Measure the maximum and minimum diameters of the circular notch opened by the phosphor on the standard sample, and take the average value. GB/T 4070—1996
15.4.5 Measure the average diameter of the notch of the sample piece in the same way, and do three tests at the same time for the sample piece and the standard piece. 15.4.6 Take the arithmetic mean of the three tests, and compare the average diameters of the two notches. The sample piece should not be larger than the standard piece. 16 Determination of dry adhesion of cathode ray phosphor 16.1 Principle
The pressure at which the powder layer on the sample is notched under the impact of a water column is proportional to the dry adhesion. 16.2 Materials
a) Standard phosphor:
b) Test phosphor;
c) Potassium silicate,
d) Strontium nitrate:
e) Glass sheet:
f) Pure water.
16.3 Schematic diagram of the device
The schematic diagram of the device is shown in Figure 5.
Pressure gauge
Trace gas valve
Figure 5 Schematic diagram of the device for determining the dry adhesion of cathode ray phosphor 16.4 Test steps
16.4.1 Simultaneously, the sample and the standard sample are precipitated and prepared according to the selected F process conditions. After the preparation is completed, the precipitate is taken out and dried. 16.4.2 Place the standard sample into the measuring device and open the air inlet pressure control valve. 16.4.3 Increase the pressure of the water column at a certain rate according to the requirements of the product technical standards. Record the pressure of the water column at the moment when a gap appears in the powder layer on the standard sample.
16.4.4 Measure the water column pressure of the test piece in the same way. 16.5 Calculation of analysis results
Test the test piece and the standard sample at the same time and take the arithmetic mean. 16.6 Tolerance
Comparing the two water column pressures, the test piece should not be smaller than the standard sample.Determine the chromaticity coordinates respectively, and the difference (change value) between the corresponding values shall meet the requirements of the product technical standards.
15 Determination of wet adhesion of cathode ray induced phosphor 15.1 Principle
Under the impact of a water column with a certain pressure and a certain flow rate, the H nozzle is kept vertical to the sample, with an equal distance, and the same impact time is used. The wet adhesion is inversely proportional to the size of the circular notch on the sample where the phosphor is washed away. 15.2 Reagents and materials
a) Standard phosphor;
b) Test mixed phosphor,
c) Potassium silicate +
d) Strontium nitrate,
e) Glass sheet;
f) Pure water.
15.3 Schematic diagram of the device
The schematic diagram of the device is shown in Figure 1.
Solenoid valve
High-level water tower
Figure 4 Schematic diagram of the wet adhesion test device for blocking ray-induced phosphor 15.4 Test steps
15.4.1 Simultaneously immerse the sample and standard sample in the selected process conditions and make a film. Test immediately after making the film. 15.4.2 Insert the nozzle of the test device into the precipitation liquid of the standard film, 1cm to 5cm away from the top of the standard sample. 15.4.3 Open the solenoid valve, and use a water column of a certain pressure to impact for several seconds according to the requirements of the product technical standards, and close the valve. 15.4.4 Measure the maximum and minimum diameters of the circular notch opened by the phosphor on the standard sample, and take the average value. GB/T 4070—1996
15.4.5 Measure the average diameter of the notch of the sample piece in the same way, and do three tests at the same time for the sample piece and the standard piece. 15.4.6 Take the arithmetic mean of the three tests, and compare the average diameters of the two notches. The sample piece should not be larger than the standard piece. 16 Determination of dry adhesion of cathode ray phosphor 16.1 Principle
The pressure at which the powder layer on the sample is notched under the impact of a water column is proportional to the dry adhesion. 16.2 Materials
a) Standard phosphor:
b) Test phosphor;
c) Potassium silicate,
d) Strontium nitrate:
e) Glass sheet:
f) Pure water.
16.3 Schematic diagram of the device
The schematic diagram of the device is shown in Figure 5.
Pressure gauge
Trace gas valve
Figure 5 Schematic diagram of the device for determining the dry adhesion of cathode ray phosphor 16.4 Test steps
16.4.1 Simultaneously, the sample and the standard sample are precipitated and prepared according to the selected F process conditions. After the preparation is completed, the precipitate is taken out and dried. 16.4.2 Place the standard sample into the measuring device and open the air inlet pressure control valve. 16.4.3 Increase the pressure of the water column at a certain rate according to the requirements of the product technical standards. Record the pressure of the water column at the moment when a gap appears in the powder layer on the standard sample.
16.4.4 Measure the water column pressure of the test piece in the same way. 16.5 Calculation of analysis results
Test the test piece and the standard sample at the same time and take the arithmetic mean. 16.6 Tolerance
Comparing the two water column pressures, the test piece should not be smaller than the standard sample.
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