If the water-cooled xenon lamp aging test chamber is not equipped with a chiller, the high temperature of the cooling water will cause the machine to alarm. If there is no pure water machine, the filter and irradiance measurement performance of the xenon lamp will be greatly affected. Simply put, not using this equipment will greatly reduce its value. Regarding some manufacturers' equipment that comes with built-in cooling function, we have also done it in the early days. It has built-in cooling function, but later found that this is not good, so we changed it back to an external one. Because if it comes with built-in cooling, it is equivalent to dividing the compressor into two parts for cooling. One part is the air temperature inside the cooler, and the other part is a cold water pipe to cool the water. Often, these two are difficult to match well because our xenon lamp has different output power of the lamp tube, or high and low temperature adjustment points. Its cooling effect needs to be matched with it. In this case, the temperature of the built-in cooling water is unstable, so these two are difficult to match well. In fact, its cooling capacity should vary, but the temperature of your cooling water must be relatively constant, In this case, it is difficult to achieve, as the cooling water temperature often changes with the output of the compressor's cooling capacity. Our cooling water is actually the most suitable, and it has been proven that the most suitable situation is to use external cooling to maintain a relatively constant temperature. If internal cooling water is used, the temperature will fluctuate. Simply put, if internal cooling is used, the temperature of the cooling water will fluctuate. If it is external, it will be more stable. The failure rate of built-in cooling is relatively high