7
Intended use
When asked about some of the most common errors
in using a ULT, Richardson says, “One big mistake
that we’ve seen in the eld is deliberate abuse.” By
that, he means using a ULT as a ash or blast freez-
er. “Sometimes, a blood bank, for example, wants to
freeze plasma of cryoprecipitate as quickly as pos-
sible,” Richardson explains. “Someone takes some-
thing at room temperature or warmer and puts it in
a ULT, when he or she requires a blast freezer.”
If someone needs a blast freezer, that is what he or
she should acquire. The use of a -80°C ULT as a blast
freezer damages the ULT. “What goes in a ULT should
be frozen,” Richardson says. “If you load a ULT full of
warm samples and expect them to be rapidly frozen,
you can get away with that for a while, but eventual-
ly, the ULT wears out.” He adds, “It’s a fairly common
event we have noticed.”
Even though a high-performance ULT can handle a
limited number of unfrozen samples, that doesn’t
make it a good idea. In general, a best practice is to
avoid placing warm samples in a ULT.
As Richardson points out, “You can break a com-
pressor in a few years by abusing a ULT.” As a re-
minder, he adds: “A −80° freezer is to store samples
essentially indenitely.”
Electrical source
To maximize the life of a ULT, there’s another element
of use to keep in mind—the plug. A manufacturer
will note the proper power for a ULT. For example,
most ULTs operate around 220 volts at 60 hertz on
a 15Amp, single-phase circuit. NuAire guidelines
state that “some customers need 115V with 20Amp
single-phase circuits. Very few freezers can maintain
even -57°C at 115V and 15Amp, the exception being
small, low interior volume freezers.”
