Cement hydration heat calorimeterIt is a professional equipment used to detect the heat release during the hydration process of cement, widely used in cement plants, scientific research institutions, and construction engineering fields. The core principle is based on precise monitoring of heat changes during the cement hydration process. Common methods include direct method and dissolution heat method. The direct method is to automatically record the temperature changes of cement mortar through high-precision temperature sensors under the condition of a constant temperature around the calorimeter, calculate the total amount of accumulated and dissipated heat in the calorimeter, and thus obtain the hydration heat of cement within a certain period of time. The law of heat of dissolution is based on Geiss's law, which measures the difference in heat of dissolution between unhydrated and hydrated cement at a specific age in standard acid, in order to determine the heat of hydration released by cement during the specified age.

　　Cement hydration heat calorimeterUsage tips:

1. Equipment calibration and inspection

Before use, it is necessary to ensure that all components of the instrument are in good condition, including the calorimeter, temperature sensor, mixing device, and control system. Calibrate temperature sensors to verify their sensitivity and accuracy, such as comparing measured values with standard thermometers. At the same time, check whether the mixing device can operate normally to avoid affecting the experimental accuracy due to loose or damaged components.

2. Sample preparation and operating procedures

Sample processing: Cement samples should be uniform and free of contamination, crushed, ground, and sieved to the specified particle size according to standard requirements. Accurately weigh 500g of cement and 250g of water (with a mass ratio of 0.5), and use a precision balance to ensure accurate proportioning.

Mixing and container selection: When mixing cement slurry, it is necessary to mix thoroughly and evenly to avoid local unevenness affecting the hydration reaction. Containers should be made of materials with high thermal conductivity and good sealing to prevent heat loss, and the container volume should match the instrument specifications.

Temperature control: The ambient temperature must be strictly stable at 20 ± 0.1 ℃, and adjusted through an external cylinder constant temperature system or laboratory air conditioning. If the water temperature is higher than 20.1 ℃, slowly add ice cubes or cold water to cool down and avoid temperature fluctuations interfering with the experiment.

3. Experimental process monitoring and data recording

Real time monitoring: After starting the instrument, continuously observe temperature changes through the display screen or software. During the initial stage of cement hydration, the temperature will rise rapidly and then gradually stabilize. It is necessary to ensure that the instrument automatically records data throughout the entire process.

Exception handling: If a sudden temperature change or equipment alarm is detected, immediately suspend the experiment and check whether the mixing device, sensor, or sealing is abnormal. For example, the mixing blade hitting the wall can cause local overheating and require repositioning.

Data integrity: After the experiment is completed, confirm that the data has been fully saved to the internal memory or external storage card to avoid losing critical information.

4. Cleaning and maintenance after the experiment

Equipment cleaning: Rinse the inner cylinder, outer cylinder, and mixing blades with clean water to remove residual cement slurry and prevent damage to components after hardening. Precision components such as temperature sensors need to be wiped with a clean cloth to avoid collisions.

Regular maintenance: Check the instrument for aging or damaged components, such as worn sealing rings that can cause heat leakage and need to be replaced in a timely manner. When not in use for a long time, the equipment should be powered on regularly to maintain stability.

5. Safety and protective measures

Operation safety: Wear protective gloves and goggles to prevent acid from splashing into the skin or eyes. If using dissolution reagents (such as nitric acid or hydrochloric acid), it is necessary to operate in a fume hood to avoid inhaling harmful gases.

Electrical safety: Ensure reliable grounding of instruments to avoid the risk of electrical leakage. After the experiment is completed, turn off all movements first, and then disconnect the power supply to prevent equipment damage or electric shock to personnel.

6. Data analysis and result interpretation

Hydration heat calculation: Calculate the hydration heat value using the integral method or heat dissipation constant method based on the temperature change curve. For example, the total hydration heat can be calculated by measuring the difference in dissolution heat at different age groups (such as 1 hour, 3 hours, 24 hours) using the dissolution heat method.

Engineering application combination: The analysis results need to be combined with engineering requirements, such as the initial hydration heat reflecting the early reaction intensity and the total hydration heat evaluating long-term performance. If the data is abnormal, it is necessary to investigate experimental conditions or sample issues.