Use Good Quality Tube

The 5mm probe's internal quartz tube (insert), with an inner diameter of only 5.4mm, serves to isolate the sample and coil. If the sample tube is too thick or deformed (not straight enough), it may swing or get stuck during spinning, even crushing the quartz insert.

The quartz tube functions to support the RF coil and isolate the temperature control gas. If the NMR sample tube is broken, the quartz tube may guide the sample downward to prevent corrosion of the coil and contamination of the probe. When the quartz tube is broken, achieving homogeneity becomes difficult. The quartz tube is valuable, with a unit price of approximately > 30,000 NT dollars. If the coil is contaminated, sensitivity will be reduced.

Avoid using high temperatures to dry the NMR sample tube to prevent deformation. Before use, the sample tube can be rolled on a flat surface to ensure it is straight. Carefully check for cracks under a light source. When inserting the spinner, pay attention to whether it is too tight or too loose.

If the probe has a severe malfunction, it may need to be sent back to Germany for repairs.

5mm 探頭（probe）內部隔離樣品 (sample) 和線圈 (coil) 的石英管 (insert) 內徑只有 5.4mm，過粗或者變形 (不夠直) 的樣品管在樣品旋轉(Spinning) 時會甩動，或卡在探頭裏甚至擠碎石英管 (Glass-Insert)。

石英管的作用是支撐射頻線圈，隔離控溫氣體，NMR 樣品管若破碎，石英管會導引樣品往下流動，以免腐蝕線圈及污染探頭。

石英管破碎時，勻場不容易。石英管價值不菲，單價約 > 3 萬元。線圈若污染，靈敏度會降低。

NMR 樣品管忌用高溫烘乾以免變形。樣品管使用前，可在平面上滾動，確定平直；對著燈光仔細檢查有無裂紋；插入轉子（spinner）時要注意是否過緊或過鬆。

探頭若嚴重故障需送回德國維修