Microwave hydrothermal instruments are widely used in scientific research and industrial fields, but the problem of temperature not reaching the set value often occurs, which may be caused by various factors.

　　1. Equipment hardware failure:

Insufficient microwave power output is one of the common reasons. The aging of magnetron (with a service life of usually 2000 hours) can lead to a decrease in microwave transmission power, and faults in high-voltage transformers or damage or contamination of waveguide systems can also affect microwave transmission efficiency. The malfunction of temperature sensors cannot be ignored, as it manifests as abnormal temperature display or large fluctuations in the heating curve. In addition, abnormal ventilation and heat dissipation systems can also affect temperature, such as blocked exhaust ducts and cooling fan failures, which can cause equipment to automatically reduce power protection and slow down the heating rate.

　　2. Issues with operation and program settings:

The mismatch of sample acid system will affect the temperature. For example, using low boiling point acids without setting gradient heating, or samples containing high organic matter without adding oxidants, may lead to abnormal reactions. Poor sealing of the digestion tank can also cause heat loss. Common reasons include aging and damage to the sealing ring, and loose lid of the tank. Programming errors are equally critical, such as setting the heating rate too low (e.g.<5 ℃/min) or setting the target temperature unreasonably (exceeding the device's upper limit), which can prevent the temperature from reaching the set value.

　　3. Solution strategy:

For hardware failures, the manufacturer should be contacted for power testing and replacement of the original magnetron or related components; Calibrate or replace the temperature sensor; Check and replace the sealing ring, gradually tighten the can lid in diagonal order; Check the exhaust ducts and cooling fans to ensure proper ventilation and heat dissipation.

For issues related to operation and program settings, it is necessary to refer to the standard digestion plan provided by the manufacturer and adjust the acid ratio; Optimize the heating program and adopt a step-by-step heating approach; Tighten the tank cap according to the specifications; Refer to the recommended program and set the heating rate and target temperature reasonably.

In addition, daily maintenance is also crucial. Monthly inspection of magnetron and sensor status, and quarterly pressure calibration; Check the sealing of the tank after each use, clean the inner wall of the chamber, calibrate the temperature sensor weekly, and test the emergency relief valve. By standardizing operation and regular maintenance, the occurrence rate of microwave hydrothermal instrument temperature not reaching the set value can be significantly reduced, ensuring stable operation of the equipment and providing reliable support for scientific research and industrial production.