高低温试验箱箱内空气循环设计要求

1.高低温试验箱对由于尺寸大或者高散热而不能使用自由空气条件试验箱试验的试验样品，应使用带空气流动（有强迫空气循环）的试验箱，除有关试验箱尺寸以外，对自由空气试验箱的其他所有要求，有强迫空气循环试验箱的设备均适用。

1 high low temperature test box due to the large size and high heat dissipation and free air condition test chamber test cannot use a test sample, should be used with air flow (forced air circulation) test box, except relevant test box size, the free air chamber of the other requirements, forced air circulation chamber the equipment is applicable.

2.速度应符合这样的要求：不应太小，以保证高低温试验箱试验样品在试验时不致过热，有不应太大，以致试验样品在试验时出现过冷，但是，尽管顺畅地变得气流的速度是有利的，然而在实践中业已发现，采用0.5m/s的风速是一种较好的折衷方案。

2 speed shall comply with such requirements: should not be too small, so as to ensure the high low temperature test box test sample is not overheating in the test, there should not be too large, so that the test sample in the trial when cold, but, although smoothly become airflow velocity is favorable, however it has been found that in practice, the wind speed by 0.5m/s is a good compromise.

3.宜尽可能均匀一致，气流方向宜垂直向上，以将由上面对流所引起的气流变化缩减到最低限度，如果风扇在前箱产生正压，然后使空气从前箱经过过滤器（如玻璃纤维栏网）逸出，则可得到均匀的气流，在前箱还可装设几个控制该高低温试验箱温度的加热器，或者，利用把加热器和过滤器的作用结合在一起的网状加热器。

3 should be as uniform as possible, the airflow direction is vertical, to cut the air caused by the convection of the above to a minimum, if the fan to generate positive pressure in the first box, and then make the air once box through the filter (such as glass fiber nets) to escape, then can get the flow evenly, heater, in the front box installed several control the high low temperature test box temperature can be or, to use the heater and a filter role together with mesh heater.