The use process of the lubricant drop point tester must follow strict operating procedures to ensure the accuracy of test results and the safety of the instrument. The following is a detailed process that integrates multiple operational guidelines and standard testing methods:

1、 Preparation work

1. Instrument inspection and cleaning

-Confirm that the appearance of the instrument is undamaged and the accessories are complete (such as oil bath, thermometer, drip cup, mixing motor, etc.).

-Clean the oil bathtub and drip cup to ensure there are no residues or oil stains, and avoid affecting the test results.

-Check that the power supply is properly grounded to prevent the risk of electrical leakage.

2. Sample preparation

-Take an appropriate amount of lubricating grease sample (usually 1-2g), evenly fill it into a standard drip cup, with a smooth surface and no bubbles.

-If impurities need to be removed, they can be pre stirred or filtered using a glass rod.

3. Medium selection and injection

-Select the appropriate thermal conductive medium (such as silicone oil, glycerin, etc.) according to the testing requirements, and inject it into the oil bath to a distance of 15-20mm from the upper edge, taking into account the thermal expansion coefficient of the medium.

-For media with high thermal expansion coefficient (such as methyl silicone oil), a higher space needs to be reserved at the liquid level.

2、 Instrument installation and parameter setting

1. Component assembly

-Fix the oil bathtub onto the instrument, insert the thermometer and secure it, ensuring that its bulb corresponds to the position of the thermometer inside the drip cup.

-Place the dropper cup and thermometer assembly containing the sample into a test tube, and secure the thermometer with a cork stopper so that the intrusion mark is flush with the lower edge of the rubber stopper.

2. Heating system connection

-Connect the power supply (AC220V), insert the heating tube and mixing motor plug.

-The initial voltage adjustment knob is turned counterclockwise to zero to avoid sudden temperature rise.

3. Temperature control parameter setting

-Set the heating rate (usually 5-10 ° C/minute) and target temperature range (such as starting to slowly heat up 17 ° C lower than the expected drop point).

-The fully automatic instrument can directly input parameters, while the manual type requires voltage regulation to control the heating speed.

3、 Heating and testing process

1. Gradual heating

-Rapid preheating stage: Adjust the initial voltage to below 70V to avoid overheating of the medium. As the oil temperature increases, gradually increase the voltage to a stable range (ordinary medium 70-100V, methyl silicone oil 70-150V).

-Temperature control stage: When the temperature of the oil bath approaches the expected drop point, reduce the heating rate to 1-1.5 ° C/minute and maintain the temperature difference between the oil bath and the sample within 1-2 ° C.

2. Drip point monitoring

-Observe the condition of the lubricating grease, and immediately record the temperature when it overflows from the drip cup hole or drips along the glass rod.

-The fully automatic instrument automatically recognizes dripping and stops heating through sensors, while the manual type requires manual interpretation.

3. Safety precautions

-Avoid contact with high-temperature oil baths to prevent burns.

-If the medium expands and overflows, remove it promptly with a straw and do not touch it directly with your hands.

4、 Result recording and instrument maintenance

1. Data recording

-The drip temperature should be accurate to 1 ° C, and information such as heating rate and sample size should be recorded.

-Save electronic reports or paper documents for subsequent analysis and comparison.

2. Instrument cleaning

-After turning off the power, unplug the plug and clean the oil bath and drip cup after the instrument cools down.

-Regularly calibrate thermometers and temperature control systems to ensure compliance with ASTM D566 or ISO 2176 standards.

3. Fault handling

-Check the calibration status of the sensor when the temperature is abnormal.

-Uneven heating or medium leakage require contacting professional personnel for repair, do not disassemble on your own.

5、 Precautions

1. Sample requirements

-The sample should be uniform and free of bubbles to avoid delamination or interference from impurities.

-Before testing, it is necessary to restore to room temperature to prevent initial temperature deviation.

2. Environmental control

-The laboratory needs good ventilation to avoid airflow interference during the heating process.

-External temperature fluctuations may affect the stability of the oil bath, and it is recommended to operate in a constant temperature environment.

3. Operating standards

-Strictly follow the standards (such as ASTM D566) to ensure repeatability.

-Do not adjust the heating rate arbitrarily, otherwise it may lead to droplet point deviation.