What temperature range is safe for my NMR tube?

For whatever reason, if the sample temperature must be chilled down, or oppositely heated up beyond room temperature, the recommend glass of choice is ASTM Type 1 Class A glass. NMR tubes made from this glass type have thermal expansion rates 60% less than that of standard boro-silicate glass. Since some NMR tubes require withstanding temperatures down to -70 ^oC or up to +200 ^oC, the increased expansion rate can cause conventional boro-silicate NMR tubes to crack. We have a full line of NMR tubes that are made from ASTM Type 1 Class A glass under the “Select Series” Brand, which you can see on our web page www.nmrtubes.com.