Thermo Scientific Heratherm General Protocol Gravity Convection Oven

Thermo Scientific Heratherm General Protocol Gravity Convection Oven. A drying oven's job is to remove water and nothing else, which is a harder specification than it sounds.

The models differ by 65L 120V, 65L 230V, 774L 400V, 105L 120V, 105L 240V, 176L 120V and 7 more.

Gravity or forced air

A gravity convection oven moves air by warmth alone. It is slower and less uniform, and that is exactly why it suits powders, light material and anything that would blow around — the air barely moves.

A forced air oven has a fan. It heats faster, holds a far more uniform temperature and recovers quickly after the door opens, which matters when the result is a weight. It also disturbs light samples and can carry contamination from one shelf to another.

Uniformity is the specification that matters

A gravimetric result depends on every sample seeing the same temperature. An oven with a five-degree spread between its top and bottom shelf will produce a five-degree spread in results, and nothing in the numbers will reveal it. Load loosely, leave the shelves space, and do not fill the chamber.

Where it is used

• gravimetric and moisture analysis
• glassware drying
• materials and soils testing
• sample preparation

Practical note

Cool dried samples in a desiccator, not on the bench: a hot sample takes moisture back from the room air faster than it can be weighed.

Supplied in 13 models.