The low-temperature overflow water bath for asphalt mixture density testing is an important laboratory instrument used to determine the density of asphalt mixtures. It mainly operates through a constant-temperature water bath and an overflow constant-level structure, in combination with a hydrostatic balance to complete the water displacement test method.Since the equipment operates continuously under heating, cooling, and water circulation conditions, proper routine maintenance is essential to ensure testing accuracy and extend service life. The following summarizes the main maintenance requirements of this equipment from several aspects.

I. Routine Cleaning and Maintenance

During operation, impurities or specimen debris may easily accumulate inside the equipment's water tank. Therefore, the following measures should be observed:

Promptly remove any residual matter from the interior of the water tank after the completion of each test.

Periodically replace the water in the tank to prevent water quality degradation, which could compromise temperature control accuracy.

Wipe the interior walls using a soft cloth or a neutral detergent to avoid scratching the stainless steel surface.

Strictly prohibit the use of strong acids or strong bases to clean the equipment.

II. Water Level and Overflow System Maintenance

The core component of the overflow tank is the constant water level system; therefore, particular attention should be paid to the following checks:

Regularly inspect the overflow outlet to ensure it is free of blockages.

Ensure that the overflow piping remains unobstructed to prevent abnormal water level fluctuations.

Verify that the water level consistently remains at the standard overflow operating level.

If water level fluctuations are observed, immediately troubleshoot for potential issues with the pump or piping.

III. Temperature Control System Maintenance

This equipment features both heating and cooling capabilities, making the temperature control system a critical component:

Regularly inspect the heater to ensure it is functioning properly.

Verify that the cooling compressor is operating stably and free of any abnormal noises.

Calibrate the temperature control system to ensure temperature accuracy remains within a range of ±0.1°C.

Avoid operating the equipment for extended periods in environments characterized by high humidity or poor ventilation.

IV. Electrical System Inspection

To ensure the safe operation of the equipment, please observe the following:

Check the power cords for signs of aging or damage.

Ensure proper grounding to prevent the risk of electrical leakage.

Periodically check the control panel buttons and display to verify they are functioning correctly.

Avoid frequent power cycling to minimize electrical stress.

V. Maintenance of Accessories for Hydrostatic Balances

As this equipment is typically used in conjunction with a hydrostatic balance, it should be maintained concurrently:

Ensure that the suspension basket is securely attached to its support stand.

Periodically inspect the suspension basket for any signs of deformation or corrosion.

Perform a zero-point calibration prior to use.

Avoid overloading the equipment, as this may compromise measurement accuracy.

VI. Long-Term Storage and Maintenance

If the equipment is to remain unused for an extended period, the following procedures should be performed:

Drain all water from the water tank.

Clean and dry the internal components to prevent rust.

Disconnect the power supply and cover the unit with a dust cover.

Periodically power on and operate the unit to maintain system stability.

VII. Summary

As a critical auxiliary device for asphalt mixture density testing, the low-temperature overflow water tank requires a maintenance focus on water quality management, ensuring the unimpeded operation of the overflow system, maintaining temperature control stability, and ensuring electrical safety. Only through standardized operation and regular maintenance can the accuracy and reliability of test data be guaranteed, thereby providing stable support for quality control in road engineering.