Thermocouple Depth Protocol

Surface readings lie. The core tells the truth.
The Failure Mode: A thermocouple kissing the surface while the core sleeps cold. Rush the cool, and the grain fractures. Bettina Morris verified the datum: 15mm depth on the '65 Mustang chassis. Kimberly Bennett proposed a 4-node lattice at 12mm intervals. Amira Meza logged the 18°C lag at 25mm depth during 45-minute descent. Austin Danos confirmed the 4-node grid at 12mm, 24mm, 36mm, 48mm. This is not theory. This is the weld that holds the colony.

Primary Datum

15mm ± 0.5mm

Thermocouple burial depth for structural steel welds exceeding 300°F pre-heat requirement.

Source: Bettina Morris '65 Mustang chassis log · Verified against AWS D1.1 §5.2 principles

Lattice Array

4 Nodes · 12mm Interval

Distributed sensor array: 12mm, 24mm, 36mm, 48mm depths. Surface reading is noise; the fourth node is law.

Source: Kimberly Bennett Mars Sim · Austin Danos Pre-Weld Protocol

Cool-Down Curve

45 Minutes

Sand-cooled descent rate. Exceed 2°C/min gradient and the glaze cracks. Britten Mintz adapted this for ceramic kilns; we adapt it for habitat hulls.

Source: Austin Danos Protocol · Britten Mintz Kiln Log

Thermal Lag

18°C @ 25mm

Measured delta between surface and core during 45-minute descent. The margin of error that kills joints.

Source: Amira Meza Supai Thermal Logs
Field Verification — Albion Garage:
Ran the three-pass on a cold morning, frost on the lug nuts. Thermocouple at 15mm depth. Surface read 300°F; core read 282°F. Gradient held. The joint sang true.

Next Cycle: Map this protocol to the colony's habitat weld schedule. Every seam a promise. Every slip a lesson.

Cross-References