Which statement about oven requirements is NOT correct?

• A. The oven must maintain 110 ± 5 °C.
• B. The oven must operate with a 100–200 °C range.
• C. Temperature stability during drying is not required.
• D. The oven temperature must be controlled within ±5 °C during drying.

Answer: (C)

Drying samples for asphalt testing requires a stable, precise heat source. You want the oven to hold a specific target temperature so moisture is removed consistently across tests. The standard practice is to keep the oven around 110°C with a tight tolerance, typically ±5°C. That stability matters because if the temperature drifts, you can over-dry or under-dry the sample, leading to inaccurate mass loss and unreliable results. A broad range like 100–200°C doesn’t ensure the same drying rate or water removal, which is why it isn’t acceptable for precise testing. Therefore, insisting that temperature remains controlled within ±5°C during drying is the correct requirement, and stating that temperature stability isn’t needed is not correct.