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Convert angular velocity (angular speed) between radian per second (rad/s, SI base), revolutions per minute (rpm = 2π/60 rad/s), degrees per second (deg/s = π/180 rad/s), and hertz (Hz, used as revolution per second = 2π rad/s). Converts via rad/s to the target unit and lists all four equivalents. Note: 1 Hz in angular-frequency context means one full revolution per second, so 1 Hz = 2π rad/s ≈ 6.283185307 rad/s. Reference: vinyl LP 33⅓ rpm ≈ 3.49 rad/s, car engine idle ~800 rpm ≈ 83.8 rad/s.
Convert illuminance between lux (lx = lm/m², SI base), kilolux (1 = 1000 lx), footcandle (1 = 10.7639104 lx), phot (1 = 10000 lx), and nox (1 = 0.001 lx). Converts via lux to the target unit and lists the equivalent value in all five units for reference. Reference values: full moon ≈ 0.25, office lighting ≈ 300–500, overcast day ≈ 1000, direct sunlight ≈ 100000 lux.
Convert thermal resistance between K/W (kelvin per watt, SI base), °C/W (1 = 1 K/W, since Δ1 K = Δ1 °C exactly), and °F·h/BTU International Table (1 = 1.8956342 K/W). Converts via K/W to the target unit and lists the equivalent value in all three units for reference. Reference values: CPU heatsink ≈ 0.1–0.3, LED thermal path ≈ 5–20, natural convection ≈ 1 K/W.
Uniform corrosion rate by weight loss per ASTM G1: CR (mm/a) = 87.6 × ΔW / (ρ × A × t), with ΔW in mg, ρ in g/cm³, A in cm², t in hours. Also reports mpy (mils/year = mm/a × 39.37) and an indicative NACE-style carbon-steel rating (excellent/good/fair/poor). Used for immersion tests and coupon exposure.
Convert convective heat transfer coefficient (film coefficient h) between W/(m²·K) (watt per square metre-kelvin, SI base, = W/(m²·°C)) and kcal/(m²·h·°C) (1 = 1.1627778 W/(m²·K)). Converts via W/(m²·K) and lists both equivalents. h depends on flow regime and surface, not material. Typical ranges: natural-convection air ≈ 5–25, forced air ≈ 25–250, still water ≈ 100–1000, boiling/condensing water ≈ 2500–50000+ W/(m²·K).
Convert thermal conductivity between W/(m·K) (watt per metre-kelvin, SI base, = W/(m·°C)), kcal/(m·h·°C) (1 = 1.1627778 W/(m·K)), and BTU/(hr·ft·°F) (1 = 1.7307347 W/(m·K)). Converts via W/(m·K) to the target unit and also lists the equivalent value in all three units for reference. Reference values: copper ≈ 401, aluminum ≈ 237, steel ≈ 50, water ≈ 0.6, air ≈ 0.026, insulation foam ≈ 0.03 W/(m·K).
Convert between Brinell (HB), Vickers (HV), and Rockwell (HRC / HRB) hardness via ASTM E140 tabulated data with linear interpolation. Three material classes: carbon/alloy steel (HV 100–960), austenitic stainless (HV 100–600), and cartridge brass (HV 40–200). Any input scale produces all the others; a scale that does not apply in the current hardness band returns 'out of range'. Indicative only — not for acceptance testing per ASTM E140.
Compute engineering tensile strength σ_uts = F_max/A₀, yield strength σ_y = F_y/A₀ (optional), and the yield ratio σ_y/σ_uts from a uniaxial tension test. Forces in kN, area in mm² → stress in MPa. A₀ is the original cross-section. Yield ratio <0.55 high ductility, 0.55–0.85 moderate, >0.85 low ductility.
Linear and volumetric thermal expansion of an isotropic material. Linear: ΔL = α·L₀·ΔT, L₁ = L₀·(1+α·ΔT). Volumetric: ΔV = 3α·V₀·ΔT (β = 3α for isotropic solids). Built-in typical α for carbon/alloy steel, aluminum, copper, austenitic stainless, titanium and glass, plus custom. ΔT in K or °C, length in mm, volume in mm³.
Thermal stress in a fully constrained member under a uniform temperature change: σ_th = E·α·ΔT. Built-in typical Young's modulus E and expansion coefficient α for carbon/alloy steel, aluminum, copper, austenitic stainless and titanium, plus custom values. ΔT in K or °C (same magnitude), result in MPa. Heating (ΔT>0) → compressive stress in the member.
Solve Young's modulus (modulus of elasticity) in the linear-elastic region using E = σ/ε (Hooke's law). Three directions: modulus E = σ/ε, stress σ = E·ε, strain ε = σ/E. Pick the unknown, supply the other two positive values. Result in MPa with a GPa reading (e.g. steel ≈ 200 000 MPa).
Compute the air change rate (ACH / n) of a room from the outdoor supply airflow Q and the room volume V: n = Q/V (1/h). Three modes: solve ACH (given Q and V), solve airflow (given n and V), or solve volume (given n and Q). Flow in m³/s/m³/h/CFM, volume in m³/ft³/L. Also reports the well-mixed single-zone purge time to reach a target residual fraction ε (default 1%): t = −ln(ε)/n hours.