Thermal analysis & ovens
Differential Scanning Calorimeter (DSC)
Measures the heat flowing into or out of a small sample compared with an empty reference pan while both are heated or cooled. It shows melting, crystallisation, glass transitions and polymorphic changes.
- Pharmaceutical
- Polymers and plastics
- Food
- Materials research
- Chemicals
TROUBLESHOOTING
Common problems, causes and fixes
Noisy or drifting baseline
Likely causes
- • Contaminated sensor
- • Unstable purge gas flow
- • Pan not sitting flat
What to do
- • Clean the cell by bake-out
- • Check gas regulator and flow
- • Use flat, undamaged pans
Indium onset out of limits
Likely causes
- • Calibration out of date
- • Wrong heating rate or pan type compared with the calibration
- • Contaminated indium
What to do
- • Recalibrate
- • Calibrate under the same conditions as the method
- • Use fresh indium
Unexpected sharp exotherm
Likely causes
- • Decomposition
- • Pan burst or lid moved
What to do
- • Check the sample by TGA
- • Use vented pans and lower end temperature
Broad, unclear melting peak
Likely causes
- • Large or uneven sample
- • Heating rate too high
- • Impure or mixed polymorphic sample
What to do
- • Use a smaller, flatter sample
- • Reduce the heating rate
- • Confirm with XRPD or microscopy
Small endotherm near 100 °C
Likely causes
- • Water in the sample or condensation in the cell
What to do
- • Use a pierced lid or dry the sample
- • Check the purge gas is dry
In LimsPulse · Calibration Management
Keep every DSC in control: usage logs, calibration and maintenance schedules, and automatic blocking of overdue instruments.