ASTM D3828-1997 Standard Test Method for Flash Point Determination with Small Scale Closed Cup Tester
ASTM D3828-97 “Standard Test Method for Flash Point Determination with Small Scale Closed Cup Tester” is used to measure or describe the sensitivity of materials, products, or mixtures to heat or flame under controlled laboratory conditions. It is not used to describe or evaluate the risk of ignition of materials, products, or mixtures under actual conditions. However, the measurement results can be used as a factor to evaluate the risk of fire under specific conditions.
A Preface
Flash points are usually used to determine a sample at a specific temperature. At the set temperature, the mixture of steam and air of the sample to be tested is close to thermal equilibrium. See test method D3941 for other flash point devices operating at specified temperatures.
ASTM D3828-1997 Standard Test Method for Flash Point Determination with Small Scale Closed Cup Tester
1. Scope
1.1 This test method covers the procedure of using a small scale closed cup instrument to determine the flash point. This program can determine the actual flash point of the sample and whether the sample flashover (flashover/non-flashover) at a specific temperature.
1.2 This standard is used to measure or describe the sensitivity of materials, products or mixtures to heat or flame under controlled laboratory conditions. It cannot be used to describe or evaluate the fire risk of materials, products or mixtures under actual conditions. However, the measurement results can be used as a factor to evaluate the risk of fire under specific conditions.
1.3 This method uses international units, and the values in parentheses are for reference only.
1.4 This standard does not cover the relevant safety precautions, only the safety content related to use. The limitations of the method and the safety and health procedures should be determined before using the method. See Note 8, footnote B of Table 1, A2.1, A2.2, and Material safety data sheets for the products tested for specific hazard descriptions.
2. Reference materials
2.1ASTM Standard:
D3941 Test method for Determination of flash Point by equilibrium with a closed cup apparatus
2.2ISO Standards
Guidance 34 Guidelines for Standard Material Production Quality assurance systems
Guide 35 Testing of standard materials – General and statistical principles
ASTM D3828-1997 Standard Test Method for Flash Point Determination with Small Scale Closed Cup Tester
Step 3: Terminology
3.1 Definition:
3.1.1 Flash point — the lowest temperature at which a sample vapor, calibrated to atmospheric pressure of 760 mm Hg (101.3kPa), will flash in contact with a flame under specified test conditions.
3.1.1.1 Explanation — The specimen shall be considered to have flashover if the flame appears and rapidly spreads over the entire surface of the specimen.
3.1.1.2 Note — Sometimes, especially near the actual flash point, the introduced test flame will appear blue halo, or the flame will expand. This is not a flash fire and should be ignored.
3.1.2 Thermal balance — When the ignition source is introduced, the sample liquid in the oil cup of the flash point meter and the vapor above it are at the same temperature.
3.1.2.1 Illustration – In fact, the thermal equilibrium condition is not fully achieved. Although thermal equilibrium can be achieved, the temperature in the test cup is not uniform due to the temperature difference between the hot liquid and the cold lid and ignitor.
ASTM D3828-1997 Standard Test Method for Flash Point Determination with Small Scale Closed Cup Tester
4. Overview of test methods
4.1 Method A (flash/No flash test) : — Use a syringe to inject the sample into the test cup of the flash point meter under specific temperature conditions. After the specified time, the test flame is introduced to observe whether the flash fire occurs.
4.2 Method B (Limited or actual flash Point) :
4.2.1 Inject the sample into the oil cup of the flash point meter maintained at the expected flash point temperature. After the specified time, the test flame is introduced to observe whether the flash fire occurs.
4.2.2 Remove the sample from the oil cup, clean the oil cup, and then raise or lower the cup temperature by 5 ° C (9 ° F) depending on whether there has been a flash fire before. Add the new sample and do the test again. Repeat this step until the flash point is accurately measured to 5 ° C (9 ° F).
4.2.3 Repeat this step at 1 ° C (2 ° F) intervals until the flash point is measured accurately to 1 ° C (2 ° F).
4.2.4 If the measurement accuracy is required to be improved, the interval shall be 0.5 ° C (1 ° F) until the flash point is measured, which is accurate to 0.5 ° C (1 ° F).
ASTM D3828-1997 Standard Test Method for Flash Point Determination with Small Scale Closed Cup Tester
Table I Calibration of the measuring instrument
| Materials | Parylene A, C (warning) B | N-butanol A (warning) B |
| Specific gravity 15.6/15.6℃ (60/60 oF) | 0.860～0.866 | 0.810～1.812 |
| Boiling point range, ℃ (oF) | 138.35 (281.03), Max 2 (4) | 117.5 (243.5), Max 2 (4) |
| Freezing point, ℃ (oF) | Minimum 52.2 (11.23) | Minimum -90 (-130) |
| Flash point, ° C (oF) (acceptable range) | 25.6±0.5 (78±-1) | 36.6±0.8（97.9±-1.7） |
A Standard sample, sold by Plillips Petroleum Company, drayer.o; Bergen.Tx79007
B Warning: Be careful when handling xylene and n-butanol to avoid injury
C Gas chromatography for light hydrocarbons and C6 below 500ppm(V)
ASTM D3828-1997 Standard Test Method for Flash Point Determination with Small Scale Closed Cup Tester
5. Meaning and application
5.1 Flash point can measure the sensitivity of a specimen to heat and flame under controlled laboratory conditions. It is only one of many indicators to evaluate the combustion hazard of materials.
5.2 Flash points are used in transport and safety codes to define the flammability and flammability of materials and to classify them accordingly. The precise definition of these categories should refer to specific norms.
5.3 Flash point can represent volatile or flammable substances present in relatively non-volatile or non-flammable materials.
5.4 Fewer samples (2 ~ 4 ml) can be used to reduce the test time (1 ~ 2 minutes).
ASTM D3828-1997 Standard Test Method for Flash Point Determination with Small Scale Closed Cup Tester
Step 6 Instrument
6.1 Test Cup and Lid Assembly — See Figure A1.1, Table A1 in Appendix for important dimensions and requirements of the instrument. Details of instruments and accessories are given in Appendix A1. More than one instrument is required for temperatures ranging from -20 ° C to 300 ° C.
7. Harmfulness
7.1 When the flame is first introduced in the test, the operator needs to take appropriate safety measures. On the first ignition, the specimen containing the low flash point material will produce a large flame.
7.2 When the temperature exceeds 40 ° C (104 ° F), when the temperature of the instrument increases, keep the hand away from the test cup unless the operating handle is used.
ASTM D3828-1997 Standard Test Method for Flash Point Determination with Small Scale Closed Cup Tester
8. Sample
8.1 If no measures are taken to prevent volatilization of volatile substances in the sample, falsely high flash point values will be obtained. There is no need to open the container to transfer the sample unless the sample temperature is at least 10 ° C (18 ° F) below the expected flash point.
8.2 Do not use plastic (polyethylene, polypropylene, etc.) bottles to hold samples as volatile substances can diffuse through the walls of plastic bottles.
8.3 2 ml or 4 ml sample should be used for each test. At least 50 ml of samples were taken from the site and stored in clean, airtight containers.
9. Preparation of instruments
9.1 Place the tester on a horizontal and stable plane. Unless the tester is placed in a windless place, the tester should be covered on three sides. Do not test in a laboratory fume hood or near a blower.
9.2 Read the instructions and precautions of the instrument, and operate the control keys of the instrument correctly. The low temperature test temperature is within room temperature ~ 110℃(230℉). High temperatures range from 100 to 300 ° C (212 to 572 ° F).
ASTM D3828-1997 Standard Test Method for Flash Point Determination with Small Scale Closed Cup Tester
10. Calibration and calibration
10.1 Draw a curve between the control temperature and the thermometer reading before the first use;
10.1.1 Turn the thermometer control button counterclockwise to the end (0 reading) (Note 1). Turn the temperature control button clockwise until the indicator lights up (Note 2). Continue to rotate the button to the next tick. When the thermometer mercury does not continue to rise, record the dial reading and the thermometer reading. Repeat this operation until the full range of the instrument is completed. Plot the dial reading against the temperature.
Note 1 — When the instrument has two temperature control knobs, the fine control button (center, small button) is always placed in the middle during the calibration process, and only the coarse control button (external, large button) is used.
Note 2 — WHEN TESTING at the LOW temperature end, IT IS NOT necessary TO TURN ON the indicator AND IT IS NOT necessary TO increase the TEMPERATURE unless THE temperature is to BE reached at a higher scale value.
10.2 Confirm the performance of the instrument at least once a year by measuring the flash points of standard samples listed in Appendix A2 that are close to the flash point range of the sample to be tested. The flash point of the standard sample shall be determined according to the procedure described in Section 12 Method B of this test method and the results shall be corrected to the value at standard atmospheric pressure (see Section 13). The resulting flash point values should be within the confidence ranges of the values listed in Table A2.1 for known standard samples or calculated values for unlisted standard samples (see Appendix A2).
10.3 When the performance of the instrument has been confirmed, the flash points of the secondary working standard samples (SWSs) and their confidence ranges can be determined. These secondary standard samples can then be used for routine performance checks (see Appendix A2).
10.4 When the obtained flash point value is not within the confidence range of 10.2 or 10.3, check the condition and operation of the instrument to ensure compliance with the conditions listed in Appendix A1, in particular the tightness of the cup lid (A1.1.1), the action of the switch, the position of the igner (A1.2), and the position and Angle of the temperature measuring device. After adjustment, retest with fresh samples, paying special attention to the details of the operating procedures described in the test method.
Method A – Flash/No flash test
ASTM D3828-1997 Standard Test Method for Flash Point Determination with Small Scale Closed Cup Tester
11. Operation steps
11.1 Calculate the target flash point value according to the following formula:
(Ⅰ) Target flash point, ℃=Sc-0.25(101.3-A)
(Ⅱ) Target flash point, ℃=Sc-0.03(760-B)
(Ⅲ) Target flash point, ℃=Sf-0.06(760-B)
Among them:
Sc= standard value or target flash point value not corrected by atmospheric pressure, ° C
Sf= standard value or target flash point value not corrected by atmospheric pressure, ℉
B= ambient atmospheric pressure, mmHg
A= ambient atmospheric pressure, kPa
11.2 The atmospheric pressure used in this calculation shall be the ambient atmospheric pressure of the laboratory at the time of the test. Many anhydrous barometers, such as those used in weather stations and airports, should first be corrected to the air pressure value at sea level. Do not use this type of barometer.
11.3 Select the appropriate instrument recommended by the manufacturer for flash point determination (8.2).
11.3.1 Check the cleanliness of the oil cup, cover and mechanical switch. Use suction paper to wipe clean if necessary. Put the lid on the cup and close it tightly. It is convenient to clean the pinhole where the sample is added with a tubular tube washer.
11.4 If the test flash point is higher than the ambient temperature, turn on the power supply of the instrument, turn the temperature coarse control button clockwise to the end, and make the indicator light on (Note 3). When the temperature indicated by the thermometer is 3 ° C (5 ° F) lower than the target temperature, turn the temperature control coarse knob counterclockwise to the desired control point to reduce the heating speed of the test cup (11.1). Record the readings on the thermometer as the indicator lights slowly come on and go off. Adjust the temperature fine control knob if necessary to obtain the expected test temperature. When the test temperature is reached, the indicator light is on and off, and the sample is ready to be introduced at this time.
ASTM D3828-1997 Standard Test Method for Flash Point Determination with Small Scale Closed Cup Tester
Note 3 — Unless it is to be heated to the highest temperature, the coarse control button can be directly turned to the appropriate position (9.1) to reach the target temperature to obtain the expected temperature, without having to turn the coarse control button to the bottom and re-adjust. This eliminates the need to pay more attention to the instrument during heating.
11.5 Draw 2 ml of the sample to be tested with a syringe and take it to the pinhole where the sample is added. Be careful not to lose the sample. Inject all the samples into the test cup and remove the syringe.
Note 4 — When using a higher temperature tester, or when the test temperature is higher than 100 ° C, add 4 ml of sample to the oil cup, draw 4 ml of sample with a 5 ml syringe, and inject all of it into the sample cup at a time. See Appendix A1.5. The timer is set for 2 minutes.
11.6 Turn the timer knob clockwise to the stop position. Light a match or other ignition period. Open the air valve slowly and ignite the tinder and test flame. Adjust needle valve to test flame diameter up to 4 mm (5/32- inch).
11.6.1 When the time signal indicates that the sample reaches the test temperature, open the switch slowly and evenly, introduce the test flame, and then completely shut down for about 2.5 seconds. Look carefully at the opening of the cup for flashes of fire.
11.6.1.1 Test flame must not be introduced into the sample more than once. Fresh samples should be used for each test.
11.6.2 When a large flame appears and rapidly spreads to the entire surface of the sample (3.1.1), the sample is considered to flash fire.
11.7 Record test results (flash or not) and test temperature. Record the instrument used, ASTM or IP standard number.
11.8 Close the air valve so that the fire source and test flame are extinguished. Remove the specimen and clean the instrument when the cup temperature drops to a safe temperature.
11.9 If the target temperature is lower than the ambient temperature:
11.9.1 The instrument power switch should be in the off position. Make the cooling substance with suitable materials (Note 6). Raise the cover and switch assembly, and prevent the cooling block from entering the test cup. Be careful not to damage or stain the test cup. When the thermometer reading is about 10 ° C below the target temperature (warning, see Note 8), remove the cooling block and quickly wipe the bottoms of the cap and igners with paper to remove moisture. Close the lid and igniter immediately and tighten the lid. The sample was then prepared to be added with a syringe, and both the syringe and the sample were cooled to 5 to 10 ° C (10 to 20 ° F) below the target temperature.
ASTM D3828-1997 Standard Test Method for Flash Point Determination with Small Scale Closed Cup Tester
Note 6– Crushed ice and water may be used as coolant if the target or specified temperature is at least 5 ° C (40 ° F) below room temperature; If below 5 ° C (40 ° F), then liquid carbon dioxide (dry ice) and acetone (warning, see Note 8) are suitable coolants. If a suitable coolant is not available, refer to the cooling method described in the instrument manufacturer’s manual.
Note 7 — Caution — Do not cool the sample below -38 ° C (-36 ° F), the freezing point of mercury.
Note 8 — Warning — Acetone is highly flammable. Do not allow dry ice to come into contact with eyes or skin.
11.9.2 Follow the steps of 11.5-11.8.
11.9.3 When the target temperature is lower than the ambient temperature, do not set the timer time. Adjust the test flame so that the temperature rises to the target temperature under the stable condition of the chamber. Introduce the test flame immediately. In order to reduce the test time, when the temperature is close to the ambient temperature, slowly turn the tester control button clockwise until the target temperature.
11.9.4 Continue steps from 11.6.2 to 11.8.
Method B- Determination of the actual flash point
ASTM D3828-1997 Standard Test Method for Flash Point Determination with Small Scale Closed Cup Tester
12. Operation steps
12.1 Select the appropriate instrument to measure the flash point according to the flash point to be measured (9.2)
12.1.1 Check the cleanliness of oil cups, caps and mechanical switches. Use suction paper to wipe clean if necessary. Put the lid on the cup and close it tightly. It is convenient to clean the pinhole where the sample is added with a tubular tube washer.
12.2 If the test flash point is higher than the ambient temperature, turn on the power supply of the instrument, turn the temperature coarse control button clockwise to the end, and make the indicator light on. When the temperature indicated by the thermometer is 3 ° C lower than the target temperature, turn the temperature coarse control knob counterclockwise to the expected control point (that is, the scale of the flash point corresponding to the temperature point of the calibration curve). Record the readings on the thermometer as the indicator lights slowly come on and go off. Adjust the temperature fine control knob if necessary to obtain the accurate test temperature.
12.3 Draw 2 ml of the sample to be tested with a syringe and take it to the pinhole where the sample is added. Be careful not to lose the sample. Inject all the samples into the test cup and remove the syringe (Note 4).
12.3.1 Turn the timer knob clockwise to the stop position. Light a match or other ignition period. Slowly open the air valve and light the fire
And test flame. Adjust needle valve to test flame diameter up to 4 mm (5/32- inch).
12.3.2 When the time signal indicates that the sample reaches the test temperature, open the switch slowly and evenly, introduce the test flame, and then completely shut down for about 2.5 seconds. Look carefully at the opening of the cup for flashes of fire.
12.3.2.1 When a large flame appears and rapidly expands to the entire surface of the sample (3.1.1), the sample is considered to flash fire.
12.3.3 Close the air valve so that the fire source and test flame are extinguished. Remove the specimen and wash the instrument when the cup temperature drops to a safe temperature.
12.4 If a flash fire is observed in 12.3.2, repeat steps 12.2 and 12.3 to test the new specimen at 5 ° C (9 ° F) below that flash point.
12.4.1 Repeat the steps of 12.4 if necessary, lowering the temperature by 5 ° C each time until no flash fire is observed.
Proceed to step 12.6.
12.5 When no flash fire is observed at 12.3.2, repeat the steps of 12.2 and 12.3 and test the new specimen by increasing 5 ° C each time until flash fire is observed.
12.6 After flash fire is produced at 5 ° C intervals, the operation is repeated at 1 ° C intervals starting from lower temperatures until flash fire is observed. Record the temperature of flash fire and use it as flash point after temperature correction. Atmospheric pressure (10.2) was recorded.
12.7 The flash point determined at 12.6 is within 1 ° C of error, and if accuracy needs to be improved, retest the new specimen at a temperature 0.5 ° C lower than the flash point observed at 12.6. If no flash point is observed, the error of the flash point observed with 12.6 is within 0.5 ° C. If a flash fire was observed at a lower temperature, the latter temperature was recorded as the flash point.
12.8 Close the fire and test flame with the air valve. Remove the specimen and wash the instrument when the cup temperature drops to a safe temperature.
12.9 When the expected flash point is lower than the ambient temperature:
12.9.1 The instrument power switch should be in the off position. Make the cooling substance with suitable materials (Note 7). Raise the lid and igniter assembly, and prevent the cooling block from entering the test cup. Be careful not to damage or fluster the test cup. When the thermometer reading is approximately 5 to 10 ° C (10 to 20 ° F) below the target temperature (warning, see Note 7), remove the cooling block and quickly wipe the bottoms of the cap and igners with paper to remove moisture. Close the lid and igniter immediately and tighten the lid. The sample was then prepared to be added with a syringe, and both the syringe and the sample were pre-cooled to 10 ° C below the target temperature.
12.9.2 Follow the steps of 12.3-12.8.
12.9.3 When the expected flash point is lower than the ambient temperature, it is not necessary to set the timer time. Adjust the test flame. Raise the temperature to 5 ° C below the expected flash point at room temperature. Introduce the test flame immediately.
12.9.4 Continue with steps from 12.3.2-12.8.
ASTM D3828-1997 Standard Test Method for Flash Point Determination with Small Scale Closed Cup Tester
Step 13 Calculate
13.1 If it is necessary to correct the observed flash points by atmospheric pressure, it is done as follows:
13.1.1 Observe and record the atmospheric pressure during the test (11.2). If the atmospheric pressure is not 101.3 kpa (760mmHg), the flash point is corrected as follows:
(Ⅰ) Flash point (℃) =C+ 0.25(101.3-A)
(Ⅱ) Flash point (℃) =F+0.06 (760-B)
(Ⅲ) Flash point (℃) =C+0.03 (760-B)
Where:
C= observed flash point value, ℃,
F= observed flash point value, ℉
B= ambient atmospheric pressure, kPa
A= ambient atmospheric pressure at test time, mmHg
14. Report
14.1 When method A (flash/no flash) is used, report whether the result at the target temperature is flash or no flash, and indicate Method A.
14.2 When the actual flash point is measured by method B, the flash point is reported to be accurate to 1 ° C (2 oF); If 12.7 is used, it is accurate to 0.5 ° C and method B is indicated.
ASTM D3828-1997 Standard Test Method for Flash Point Determination with Small Scale Closed Cup Tester
15. Precision and deviation
15.1 Precision — Statistical analysis of the results obtained by different laboratories shows that the precision of this test method is as follows:
15.1.1 Repeatability — Under the same operating conditions, using the same instrument and the same material, and operating correctly according to the test method, the probability that the difference between the two test results obtained by the continuous test exceeds the value listed in Table 2 is 1/20.
| Range of temperature | repeatability |
| 20～70℃(68～158 oF) | 0.5℃(oF) |
| Higher than 70℃(158 oF) | 0.022M0.9℃(0.0117M oF ) |
Where: M= the average of the two outcomes.
Table 2 Repeatability and reproducibility
| Temperature, ℃ (oF) | Repeatability, ℃(oF) | Reproducibility, ℃(oF) |
| 20(68) | 0．5(0.9) | 1．5(2.7) |
| 70(158) | 0．5(0.9) | 3．0(5.4) |
| 93(200) | 1．3(2.3) | 4．9(8.8) |
| 149(300) | 2．0(3.6) | 7．5(13.5) |
| 204(400) | 2．6(4.7) | 10．0(18.0) |
| 260(500) | 3．3(5.9) | 12．4(22.3) |
15.1.2 Reproducibility – There is only a one in twenty chance that the results of two separate experiments will differ by more than the following values when the same test material is used by different operators in different laboratories according to the correct operation of the test method:
| Range of temperature | Reproducibility of appearance |
| 20～70℃（68～158 oF） | 0.03(M+29)，℃(0.03(M+22) oF) |
| Higher than 70℃(158 oF) | 0.083M0.9，℃(0.045M oF) |
ASTM D3828-1997 Standard Test Method for Flash Point Determination with Small Scale Closed Cup Tester
Where M= the average of the two results.
15.2 Statistical analysis of the analysis results between different laboratories to obtain the equation, and then from the equation to obtain the above values. Values below 70 ° C were first published in 1977.
15.3 Deviation — There is no deviation because flash points are defined only according to this test method.
16. Keywords
16.1 Flammability; Fire hazard; Flammability; Flash point; Volatility of volatility
Appendix
(Mandatory information)
A1. Flash point tester
The A1.1 sample cup device consists of an aluminum alloy or stainless metal block of suitable thermal conductivity with a cylindrical depression (or sample cup) on which a cover is mounted. A thermometer is inserted into a metal block.
A1.1.1 The lid is fitted with an opening slide and a device that, when the slide is opened, can push a lit flame (4±0.5mm in diameter) into the sample tank. After the flame is introduced, the nozzle of the ignition device will intersect the plane at the lower end of the cover. The cover is also provided with an opening that extends into the sample tank for the placement of the test sample and is also a suitable clamping device to securely attach the cover to the metal block. The three openings on the lid shall be within the diameter of the sample tank. When the BOARD is in the open position, the two OPENINGS on the board should coincide exactly with the two CORRESPONDING openings on the cover.
ASTM D3828-1997 Standard Test Method for Flash Point Determination with Small Scale Closed Cup Tester
Table A1.1 Basic dimensions of flash point tester A, B
| mm | |
| Sample area:
Diameter of sample area Diameter of sample cell Depth of sample cell The top of the metal block to the middle axis of the thermometer hole Thermometer hole diameter Cover: Large opening long Large opening width Small opening long Small opening width The distance between the ends of two small openings Add the diameter of the sample hole Add the inner diameter of the sample tube Add the maximum distance between the orifice of the sample tube and the bottom of the sample tank when the lid is closed Skateboard: Large opening long Large opening width Small opening long Small opening width Proximal end of large opening to end of board The distance between the two ends of the size opening nozzle: Length of nozzle Outer diameter of nozzle Inner diameter of nozzle The middle shaft of the nozzle is above the height of the upper surface of the lid The distance between the shaft of the nozzle and the center of the metal block when the lid is closed |
61.5～62.5
49.40～49.70 9.70～10.00 16.00～17.00 约7.00 12.42～12.47 10.13～10.18 5.05～5.10 7.60～7.65 48.37～48.42 4.00～4.50 1.80～1.85 Maximum 0.75 12.42～12.47 10.13～10.18 5.05～5.10 7.60～7.65 12.80～12.85 30.40～30.45 18.30～18.40 2.20～2.26 1.60～1.65 11.00～11.20 12.68～12.72 |
A1.1.2 The electric heater is installed on the sample cup in a way that ensures effective heat transfer. The instrument shall have a heating controller to maintain temperature balance. When there is no air flow, the temperature measured by the mercury thermometer during the whole test shall be within ±0.5 ° C (±1 ° F) at low temperature and within ±2.0 ° C (±4 ° F) at high temperature. An indicator light indicates when the power is on or off.
A1.2 Test flame and ignitor flame — both should be available. The test flame can be adjusted to be inserted into the sample cup in an attempt to cause a flash fire; The igniter flame is used to hold the test flame. After introducing a fire source, the nozzle of the ignition device will meet the lower plane of the lid. The gas source of these flames may be supported by an external propane supply, or by its own contained or attached butane container (warning — see Note A1.1). A 5/32 inch (4mm) diameter measuring ring engraved on the cover near the test flame is used to ensure that the test flame is of consistent size.
ASTM D3828-1997 Standard Test Method for Flash Point Determination with Small Scale Closed Cup Tester
Note A1.1 Warning — Never inflate or replace the instrument’s own gas container after heating up or while guiding or testing the flame, or near other sources of fire.
A1.3 The instrument shall be provided with an acoustic signal. Low temperature test (room temperature ~ 100℃) after 1 minute or high temperature test (100 ~ 300℃) after 2 minutes sound signal.
A1.4 Injector, 2-mL capacity, equipped with needle and instrument, adjustable injection of 2.00± 0.05mL.
A1.5 Sample injector, 5-mL capacity, equipped with a capped needle to match the instrument, adjustable injection of 4.0±0.1 mL, can be used for high temperature test to provide the same amount of sample.
Note A1.2 — Testing samples in the temperature range -20 ° C to 300 ° C may require more than one instrument. The high temperature range starts at 100 ° C and requires 4 mL sample and 2 min test time.
A2 Instrument performance confirmation
A2.1 Reference Sample (CRM) — A CRM is a stable, pure (molar concentration 99+%) hydrocarbon or other stable petroleum product that can be measured under the specified method by a laboratory study in accordance with ASTM RR: D02-1007 or ISO guidelines 34 and 35
ASTM D3828-1997 Standard Test Method for Flash Point Determination with Small Scale Closed Cup Tester
The flash point of.
A2.1.1 Table A2.1 lists flash point values and confidence ranges for some typical benchmark samples that have been corrected to atmospheric pressure (see Note A2.2). The CRM supplier shall provide a certificate indicating the batch of the current product and the flash point of each sample measured by the specified method. The confidence ranges for these CRMS can be calculated by measuring the repeatability of the test method, which can be reduced due to inter-laboratory effects, and then multiplied by 0.7. (See RR: D02-1214 values in the study report).
Note A2.1– Data on flash points from laboratory studies are listed in Table A2.1, which can be found in Research report RR: S15-1010.
Table A2.1 Flash point values and confidence ranges of D3828 typical CRM
| hydrocarbons | Purity (mole %) | Flash point (℃) | Confidence range (℃) |
| N-decane | 99+ | 49.7 | ±1.6 |
| n-undecane | 99+ | 65.9 | ±1.9 |
ASTM D3828-1997 Standard Test Method for Flash Point Determination with Small Scale Closed Cup Tester
Note A2.2– The references, purity, flash point values, and confidence ranges listed in Table A2.1 were proposed by an ASTM test plan to determine the suitability of testing liquids in the flash point test method. If operating in accordance with ASTM RR: D02-1007 or ISO guidelines 34 and 35, other references, purity, flash point values, and confidence ranges are appropriate. The performance of these benchmarks should be determined prior to use, as flash point values will vary with the composition of each batch of benchmarks.
A2.2 Second Standard Sample (SWS) –SWS is a stable, pure (molarity 99+%) hydrocarbon or other stable petroleum product whose composition is known and can remain relatively stable.
A2.2.1 Establish the average flash point and statistical confidence range (3σ) of SWS using standard statistical techniques.
Note A2.3– A typical procedure for obtaining the average flash point is as follows: The representative subsample was tested three times on a CRM-validated instrument, the results were statistically analyzed, and the arithmetic mean was calculated after excluding abnormal values, or an inter-laboratory program involving three laboratories, each of which repeated the test of the representative sample and the mean was calculated using standard statistical techniques.