-80 degree freezer

一般的无霜厨房冷冻室的温度保持在-15摄氏度左右，家用的胸式深度冷冻室的温度可能会降到-18到-25摄氏度。尽管这种冷冻室在实验室中也很常见，但许多研究应用需要在更低的温度下储存组织提取物和专门的试剂。这种超低温设备的通用标准是那些可以保持温度低至-80摄氏度的设备（必须在更低温度下储存的材料浸泡在液氮中，液氮的沸点为-195.80摄氏度）。我们的实验室依赖于一个13立方英尺-80摄氏度的冰箱（Forma Bio-Freezer），现在已经超过25年了。尽管仍在工作，这个零下80摄氏度的冷冻室在保持温度低于零下75摄氏度的情况下有困难，并且在打开门提取或添加样品后恢复其温度。温度的波动对储存的材料是有害的。在最近的一次服务电话中，我们被告知，这台设备的零件不再可用，我们很幸运，它已经持续了15年以上。拥有一个可靠的零下80摄氏度的冰箱对申请人实验室正在进行的研究至关重要。打算共用新冷冻室的六个研究人员中有两个最近加入了我们系。因此，我们建议用一个24立方英尺的冰柜代替目前的冰柜。

The average frost-free kitchen freezer maintains a temperature of about -15 C. A domestic chest-style deep freezer descends to perhaps -18 to -25 C. Although such freezers are also common in laboratories, many research applications require tissue extracts and specialized reagents to be stored at much lower temperatures. The universal standard for such ultra-low temperature units are those that can maintain a temperature down to  -80 C. (Materials having to be stored at still lower temperatures are stored submerged in liquid nitrogen, the boiling point of which is -195.80C.) Our laboratories have depended on a 13 cu ft -80 C freezer (Forma Bio-Freezer) that is now over 25 years old. Although still working, this -80 C freezer has had difficulties maintaining temperature below -75 C on occasions, and in recovering its temperature after opening the door for retrieving or adding samples. The fluctuation in temperature is detrimental for the stored materials. During a recent service call, we were informed that parts are no longer available for this unit, and that we are fortunate that it has lasted more than 15 years. Having a reliable -80 C freezer is vital to the ongoing research of the applicants' laboratories. Two of the six researchers intending to share the new freezer have joined our department recently. Hence we propose to replace the current freezer with one that is 24 cu ft.