Cause | Solution |
---|---|
The freeze temperature set in the temperature menu (COOL) is too low for the sample. | Raise the freeze temperature gradually by steps of 0.5 °C. Please be aware that after the settings have been changed, a new calibration is required. |
The thermistor is contaminated or scratched, which results in crystallization before freezing initiation. | Clean the thermistor. If the thermistor is scratched, please contact our customer support. |
The volume of the sample solution is too low. Self-freezing of the sample is caused by a cold zone, which develops above the solution on the vial material. | Use an appropriate sample volume as it is recommended in the KNAUER user manual. The vial is contaminated. |
The vial is contaminated. | Use a new and clean vial for each measurement. |
The sample solution contains particles that function as nuclei of crystallization. | Filter the sample prior to measurement. |
The used plastic vial is not suitable for the measurement. | Use the plastic vials that are recommended by KNAUER. |
The solution to be measured is saturated with air or other gases. | Degas the sample by ultrasound prior to the measurement. |