Gradient & Soak Lab — the chamber is not the specimen

Set a target temperature. The specimen core lags along an approach curve; the grip ends sit offset by pull-rod conduction the whole time.

Model honesty: this simulator represents a generic full-frame environmental chamber with pull-rod and grip-end heat paths — it is not a performance model for the compact AUCH600 / AUCH600-HT conductive sample-environment modules. The core approach is a single-exponential T_c(t) = T_set − (T_set − T₀)·exp(−t/τ) with a fixed teaching time constant τ = 90 s; the soak time to the ±1 °C criterion follows as t = τ·ln(|ΔT_step|/1 °C), so bigger steps soak longer. The grip-end offset is a proportional leak, ΔT_grip = k·(T_set − 20 °C), with k = 0.05 for standard fixturing and k = 0.09 with stronger frame-side thermal anchoring (water-cooled grip bodies are one possible example) — in this teaching model, stronger anchoring protects the frame but steepens the specimen gradient; the direction and magnitude in a real system are design- and geometry-dependent. The ±1 °C soak criterion is likewise illustrative: the required specimen-temperature tolerance comes from the applicable test standard and laboratory procedure, not from this simulator. All parameters are illustrative teaching values, not data for any real chamber; real gradients and soak times must be measured with specimen-mounted sensors.