-80 degree freezer

厨房无霜冰箱的平均温度保持在零下15摄氏度左右。家用柜式深度冷冻机的温度可能会降至-18至-25摄氏度。尽管这种冰箱在实验室也很常见，但许多研究应用需要组织提取物和专门的试剂在低得多的温度下储存。这种超低温设备的通用标准是那些可以将温度保持在-80摄氏度以下的设备(必须在更低的温度下存储的材料被储存在液氮中，液氮的沸点是-195.80摄氏度)。我们的实验室一直依赖于一台13立方英尺-80摄氏度的冷冻机(Forma Bio-冷冻机)，它现在已经有25年的历史了。尽管仍在工作，但这台零下80摄氏度的冰柜有时难以将温度维持在零下75摄氏度以下，也难以在打开门提取或添加样本后恢复温度。温度的波动对储存的材料是不利的。在最近的一次服务电话中，我们被告知这台设备不再提供部件，我们很幸运，它已经使用了15年以上。拥有一台可靠的零下80摄氏度的冷冻机对申请者的实验室正在进行的研究至关重要。打算共享新冰箱的六名研究人员中，有两名最近加入了我们系。因此，我们建议用24立方英尺的冷冻柜取代目前的冷冻柜。

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.