Instructions for Using the Asphalt Extensometer

　　(1) Controller Operating Instructions
　　1. Temperature-related operations:
　　When the power is turned on, the top row of the meter displays the measured temperature value—the actual temperature. The bottom row displays the set temperature value.
　　The instrument uses tactile switches for parameter setting. The panel features four keys: the SET key is used to enter the temperature-setting mode, while the p, q, and t keys are used to modify data.
　　Press the SET button for 3 seconds. The upper display on the meter will show “SET,” indicating that you’ve entered the set-value setting mode, while the lower display will show the original set value. At this point, you can set and modify the control temperature.
　　Each time you press the "P" key, the flashing number increases by 1. When the accumulated value exceeds 9, it automatically carries over to the next digit.
　　Each time you press the 'q' key, the flashing number decreases by 1. When the decrement value falls below 0, it automatically shifts by 1 position.
　　Each time you press the 't' key, the flashing digits in the lower row shift one position to the left.
　　2. Valuation-based operations:
　　When the device is powered on, the LCD screen displays the name, then after a delay of about 4 seconds, it shows the operating interface, which includes time, speed, measurement value 1, measurement value 2, measurement value 3, and the average value.
　　The “Cycle” button is a repeat button: Press it once, and the water pump will start operating; press it again, and the water pump will stop; press it once more, and the water pump will start operating again. This cycle repeats continuously.
　　After the test is ready, press the “Test” button. The controller will output a signal, starting the motor and initiating the tensile testing of the specimen. Observe carefully with your eyes. When the specimen breaks, press the “Record” button once to record Length 1, Length 2, and Length 3. Once Length 3 has been recorded, the screen will display the average value. When the test is complete, you can press the “Save” button to store the time, Length 1, Length 2, Length 3, and the average value for this test. The low-temperature digital-display asphalt extensometer can save data from up to 20 test runs over a period of ten years. If you wish to perform the next test, simply press the “Test” button to start a new test.
　　Query saved data:
　　Press the “Set” key, and the screen will display the query records. Each time you press the “→” key, a new set of data will be displayed, arranged in the order of the test sequence. The system cycles through 20 sets of data. If there are no records in the system, pressing the “→” key will display “00年00月00日00时00分,” with lengths 1, 2, and 3 all set to 00000.
　　After retrieving a new set of data, press the “Clear” button to delete this data set. Once the data is deleted, it cannot be recovered under any circumstances. Please use the “Clear” button with caution.
　　On this interface, press the “Set” key to enter the [Date and Time Setting Interface]. After each data query, you must press the “Set” key to enter the [Date and Time Setting Interface], then press the “Set” key again to enter the experiment interface.
　　Date and Time Settings:
　　When operating the experimental interface, press the “Set” key to enter the record query mode, then press the “Set” key again to access the [Date and Time Setting Interface]. At this point, a cursor will appear on the screen. Use the “→” and “←” keys to move the cursor; once the cursor is positioned over the digit you wish to modify, use the “+” and “–” keys to increase or decrease its value. After changing each digit, be sure to press the “Save” key to save your changes; otherwise, the modifications will not take effect. In this system, time is displayed in 24-hour format—therefore, 4:10 p.m. should be set as 16:10.
　　On this interface, press the “Set” key to enter the experiment interface.
　　(2) Preparatory Work
　　(1) Thoroughly mix the release agent and apply it evenly to the clean, dry bottom plate of the test mold as well as the inner surfaces of the two side molds. Then, assemble the test mold into an “8” shape and place it on the bottom plate of the mold.
　　(2) Insert the prepared specimen into the mold several times, moving it back and forth from one end of the mold to the other, ensuring that the specimen slightly exceeds the surface of the mold. During this process, take care to avoid trapping air bubbles.
　　(3) After the specimen has cooled at room temperature for 30 minutes, place it in a water bath maintained at the specified test temperature for another 30 minutes. Then, remove the specimen from the water bath and use a hot scraper to smooth out any excess material above the mold, ensuring that the asphalt surface is flush with the mold surface. Next, immerse the mold—complete with its base plate—back into the water bath maintained at the specified test temperature for 1 to 2 hours.
　　(3) Experimental Procedure
　　(1) This instrument should be placed horizontally on a surface at room temperature between 0 and 40℃, with relative humidity no greater than 80%, free from vibrations and corrosive gases, and must have proper grounding protection.
　　(2) Fill the sink with water, ensuring that the water level meets the requirements of the test operating procedures.
　　(3) After connecting the power and confirming that the instrument is functioning properly, set the temperature required for the test, then activate the cooling or heating system. At the same time, press the “Cycle” button to start the water pump; once the set temperature is reached, the system will automatically stop operating.
　　(4) Turn the transmission lever to the “Neutral” position, then move the transmission and place the mold filled with the test sample onto the cylindrical pin at the extension end of the instrument. Rotate the lever to the “Fast” (50 mm/min) or “Slow” (10 mm/min) setting to engage the gears and bring the unit into working condition.
　　(5) Once everything is ready, press the test button to start the instrument. The display will show the elongation length. During the test, if you notice asphalt filaments floating on the water surface or sinking to the bottom of the tank, add alcohol or table salt to adjust the specific gravity of the water to match that of the specimen, and then continue the test.
　　(6) When the asphalt specimen is broken or reaches the test requirements, press the “Record” button. The instrument will automatically record the elongation of that specimen. When the second specimen is broken, press the “Record” button again, and the instrument will automatically record the elongation of that specimen as well. Similarly, after the third specimen is broken, press the “Record” button once more, and the instrument will record the elongation of that specimen. At the same time, the instrument will automatically calculate and display the average elongation of the three specimens.
　　(7) After the test is completed, turn off the power, remove the test mold, set the transmission lever to “neutral,” and push the transmission back into place.
　　(8) Open the drain valve to completely empty the tank, dry the instrument thoroughly, and apply an appropriate amount of machine oil to all moving parts and gear areas to prevent rusting. If the instrument is not to be used for an extended period, be sure to cover it with a dustproof cover to protect it from dust.