The AV300ac is back in service, the recently observed problems (multiple collapse of automation) originated from contaminated NMR tubes. The probe installed at this spectrometer is equipped with coils that are really close to the samples inserted. Therefore, even slightest traces of contamination outside the tube may cause clogging of the coils and, consequently, samples are stuck in the magnet.
We urgently ask you to very carefully examine each sample that you want to measure *before* inserting it into a spinner, to make sure that no contamination is transferred onto spectrometer parts. The last full overhaul of the probe took place only two months ago. Probes and coils are very sensitive equipment, and besides the difficulty to clean them, there is a potential risk to damage them in each cleaning.
Therefore, we will increase the attention that we pay to tubes that are soiled on the outer side. Any tube that does not pass our inspection will be confiscated by us and users will be banned for one month from the use of all spectrometers run in automation.
17.8.2018 - AV300ac back in service // please observe contents of E-mail!