Stirred liquid baths offer the lowest thermal uncertainty of any non-fixed-point temperature calibration medium, providing temperature stability to ±0.005°C and spatial uniformity of ±0.01°C.
1. Fluid Selection Across Temperature Ranges
Selecting the right bath fluid is critical for stability, heat transfer, and safety:
- -30°C to +50°C: Low-viscosity silicone oil (5 cSt to 10 cSt) or technical ethanol.
- +50°C to +150°C: High-temperature silicone oil (50 cSt to 100 cSt).
- 0°C to +90°C: De-ionized water with anti-corrosion additives.
2. Eliminating Frost and Condensation
When operating below 0°C, atmospheric humidity condenses and freezes into ice crystals inside the bath, creating thermal instability. The DB Thermobath Series features a thermal lid with dry nitrogen purge ports to completely eliminate moisture ingress and frost formation during sub-zero operation.