1. Set normal temperature (298-303K, 400-550 l/h gas flow, run VT selftune)
2. try with standard sample (1% CHCl3 in Acetone)Acetone) or even run Topshim 3D with 2mM sucrose sample. If final B0 Std.dev (after 3D) is below 0.5..0.8 Hz Hz your probe is most probably OK
3. check sample position in spinner and solvent height - are them ok? Maybe, in contrary, too much solvent and experiment is on elevated temperature?

4. Try extra parameter convcomp (convection compensation). Works under stable VT conditions (also check.

5. The last, but not least: sample homogeniety. Solid particles, high viscosity, aggregation?

Dear Evgeny! Feroon! there are several thougts, as the reasons can be different: bad sample, improper VT conditions (unstable temperature, incrorrect gas flow), Topshim miscalibration or even dirty or cracked insert glass.

1. Set normal temperature (298-303K, 400-550 l/h gas flow, run VT selftune)
2. try with standard sample (1% CHCl3 in Acetone) or even run Topshim 3D with 2mM sucrose sample. If final B0 Std.dev (after 3D) is below 0.5..0.8 Hz Hz your probe is most probably OK
3. check sample position in spinner and solvent height - are them ok? Maybe, in contrary, too much solvent and experiment is on elevated temperature?

4. Try extra parameter convcomp (convection compensation). Works under stable VT conditions (also check.

5. The last, but not least: sample homogeniety. Solid particles, high viscosity, aggregation?

Dear Feroon! Ferron! there are several thougts, as the reasons can be different: bad sample, improper VT conditions (unstable temperature, incrorrect gas flow), Topshim miscalibration or even dirty or cracked insert glass.

1. Set normal temperature (298-303K, 400-550 l/h gas flow, run VT selftune)
2. try with standard sample (1% CHCl3 in Acetone) or even run Topshim 3D with 2mM sucrose sample. If final B0 Std.dev (after 3D) is below 0.5..0.8 Hz Hz your probe is most probably OK
3. check sample position in spinner and solvent height - are them ok? Maybe, in contrary, too much solvent and experiment is on elevated temperature?

4. Try extra parameter convcomp (convection compensation). Works under stable VT conditions (also check.

5. The last, but not least: sample homogeniety. Solid particles, high viscosity, aggregation?