Open Flash Point Tester

Instrument Preparation

Environmental check: Ensure that the instrument is placed on a stable, vibration-free and well-ventilated workbench. The environmental temperature should be ≤ 35℃ and the relative humidity should be ≤ 85%. 
Power and air source connection:
Connect to the AC 220V power supply and ensure reliable grounding. 
If using gas ignition, connect the liquefied gas and check the gas tightness (this step can be skipped for electronic ignition). 
Cleaning and drying: Wash the test cup with petroleum ether, thoroughly remove any residues, and then dry it. 
Sample loading

Add to the calibration line: Pour the sample to be tested into the clean test cup until it reaches the specified level, avoiding overflow or insufficient amount. 
Install the temperature probe: Ensure that the temperature sensor is inserted vertically into the sample, 6.4 ± 0.1 mm away from the bottom of the cup, and positioned centrally. 
Parameter settings
Heating rate: Initially, the temperature is rapidly raised to approximately 40℃ before the expected flash point, and then it is adjusted to 4℃ ± 1℃ per minute. 
Flash point value: If the flash point of the sample is known, set it to be 10°C lower than the actual value; if it is unknown, test it gradually from a low temperature. 
Atmospheric pressure correction: The instrument automatically detects and corrects the result (for some models, manual input is required).

The working principle of the open flash point tester is based on the national standards (such as GB/T 3536), and the detection is achieved through the following core steps:

Temperature control and detection
The instrument uses a single-chip microcomputer or microprocessor to regulate the heating rate, and employs a platinum resistance temperature sensor to continuously monitor the sample temperature. When approaching the estimated flash point, the electronic ignition device is automatically activated to ignite periodically, and the flash phenomenon is captured by the flame detection module to lock in the flash point value. 
Automated process
The testing process includes steps such as sample lifting and lowering, ignition detection, and result printing. Once the flash point is detected, the system automatically raises the temperature to the ignition test stage. If the sample is ignited and continues to burn for ≥ 5 seconds, the current temperature at that moment will be recorded as the ignition point. 
Data processing
The instrument controls the heater through the CPU to heat up at the preset rate. Combined with the signal acquisition and calculation system, it achieves precise temperature control. When the flash point or ignition point reaches the set conditions, the system automatically stops heating and outputs the result.

In the research and production of industries such as petroleum, railways, aviation, and electricity, the accuracy of the open flash point tester directly affects the assessment of the safety performance of oil products. The A1020 open flash point tester, as a professional device that complies with multiple standards including ASTM D92 and GB/T3536, its calibration work is the core link for ensuring the reliability of the test data. The following elaborates on the scientific calibration method from three aspects: pre-calibration preparation, key parameter calibration, and industry adaptation points.

Before calibration, it is necessary to make thorough preparations for both the equipment and the environment. Regarding the equipment, it is essential to check if the power supply is stable at AC220V ± 10% and 50Hz, ensuring that the power supply meets the operating requirements of the instrument with a power of ≤ 500W; at the same time, clean the residual impurities in the sample cup to avoid affecting the temperature conduction. Environmental control is also crucial. The room temperature should be maintained at 5℃ to 40℃, with a relative humidity of ≤ 85%. This environmental condition can reduce the interference of external factors on the temperature sensor, laying the foundation for the calibration accuracy.

Temperature parameter calibration is a crucial step, directly affecting the accuracy of the detection. The instrument's measurement range covers from room temperature to 400℃, with a resolution of 0.1℃. The calibration process needs to be carried out in stages. Firstly, a standard thermometer is used to calibrate the heating system. At four key points of 100℃, 200℃, 300℃, and 400℃, it is confirmed whether the deviation between the displayed temperature and the standard value is within the allowable range. For the heating speed, it must strictly follow the GB/T3536 standard. The heating rate needs to be monitored in different temperature intervals to ensure that the stages from room temperature to 210℃ and subsequent stages comply with the specifications. This is the key to ensuring that the detection repeatability is ≤4℃ and the reproducibility is ≤8℃.

The calibration of the ignition system directly affects the consistency of the test results. The A1020 adopts an electronic ignition and gas flame dual-mode. During calibration, it is necessary to check whether the ignition position is accurate and ensure that the distance between the flame and the sample surface meets the standard requirements. Standard samples can be used for simulation tests to observe the ignition response time and flame stability, and at the same time verify the cooling efficiency of the forced air cooling system to ensure that the temperature recovery speed during continuous testing meets the specifications and avoids the impact of residual heat on the next test data.

The calibration of the atmospheric pressure correction function is a crucial step in improving the detection accuracy. The instrument is equipped with a pressure correction algorithm. During the calibration process, a standard pressure gauge is used to simulate different atmospheric pressure environments to verify the accuracy of the correction values. For example, in high-altitude areas, by comparing the results automatically corrected by the instrument with the manually calculated values, the deviation is ensured to be within the allowable range. This function is particularly important for detection scenarios in cross-regional operations such as aviation and railways.

The calibration of the data storage and transmission system ensures the traceability of the testing process. The A1020 is equipped with an RS-232 interface and can store 120 sets of historical data. During calibration, it is necessary to check the completeness and accuracy of the data records. By connecting to the upper computer, the timeliness and consistency of data transmission can be verified. At the same time, the touch screen input function is tested to ensure that the input errors of preset temperatures, sample labels, etc. are zero, avoiding the influence of human operation on the results.

The calibration focus varies slightly among different industries. In the petroleum industry, it is necessary to focus on verifying the stability of the instrument in detecting heavy oil and ensuring the accuracy within the 400℃ temperature range; in the power industry, attention should be paid to the low-temperature response of transformer oil and ensuring the test repeatability from room temperature to 100℃. After the calibration is completed, actual tests should be conducted using standard oil products, comparing the results with the standard values to comprehensively verify the performance of the instrument over the entire range.

The calibration of the A1020 open flash point tester should be based on national standards, combined with the characteristics of industry applications. It needs to be systematically verified from multiple dimensions such as temperature, ignition, pressure, and data. Through a scientific and standardized calibration process, not only can the compact 520mm×360mm×310mm body of the instrument's space advantage be utilized, but also the high-precision performance under the 16kg lightweight design can be guaranteed, providing reliable support for the safety detection of oil products in various industries.

When purchasing an open flash point tester, the following factors should be given priority consideration:

Verify the matching of testing requirements
It is necessary to clearly define the type of test sample (such as lubricating oil, solvent, etc.) and the flash point range. For example, for lubricating oil, an open cup method instrument should be selected because its vapor can freely diffuse into the air, resulting in a higher measured flash point compared to the closed cup method; if testing of high-temperature samples (such as heavy oil, lubricating oil) is required, it is necessary to confirm whether the heating range of the instrument covers the target temperature. 
Instrument core performance
Measurement accuracy: The high-precision temperature control system (such as ±0.1℃) and the sensitivity of vapor detection are the key factors ensuring accurate results. Attention should be paid to the stability of the heating rate (such as 5-6℃/min) and the sensitivity of the ignition system. 
Automation level: Fully automatic instruments can reduce human errors and are suitable for batch testing; semi-automatic instruments are suitable for scenarios with limited budgets or low frequency of use. 
Safety performance
The equipment should have an explosion-proof housing, an insulation layer and automatic alarm functions (such as over-temperature and over-pressure alarms), and ensure that the power supply is properly grounded to avoid the risk of electric leakage. 
Standard compliance
It is necessary to comply with industry testing standards (such as GB/T 3536, ASTM D93, etc.). Export enterprises need to pay attention to the compatibility of international standards. 
Maintenance and Cost
Choose instruments with high durability, and pay attention to the corrosion resistance and anti-aging properties of key components such as heating elements and sensors, in order to reduce long-term usage costs.

1. The spark sensor is prone to accumulate oil stains over time, which will affect the detection accuracy. It is necessary to clean the sensor with gasoline or petroleum ether frequently, and do so with great care.
2. If the buzzer keeps sounding continuously after the device is powered on, please turn it off and check if there is a short circuit in the detection ring sensor. Also, check if there are any foreign objects such as oil stains or filamentous fibers on the surface of the detection ring. After the fault is resolved, turn on the device for testing again.
3. There are two reasons for the first sweep during the instrument testing process that causes the ignition to rise:
(1) If a spark occurs during the first sweep, it indicates that the preset temperature is too high. Please lower the set temperature value and conduct the test again.
(2) If no spark occurs during the first sweep but the ignition rises, it suggests that the preset temperature is too high. At this time, check if the surface of the detection ring is clean and if there are any filamentous fibers that short-circuit the detection ring or if the detection ring is loose and causes a short circuit. After the problem is resolved, you can conduct the test again.