THRESHOLD COMPLEX EXPLORATION LOG
Designation / Log ID: 42-M39
Apparent Date/Time: 17 September 2026 / 08:47 (local) — secondary stamp reads 22:11 04 March 1977
Entry Method: Single steel door marked “O-27 OZONE CONTACT GALLERY – AUTHORIZED PERSONNEL ONLY”. Exterior clear aperture measures 1.91 m × 2.05 m. Interior aperture measures 1.74 m × 2.18 m on entry and 2.03 m × 1.89 m on exit.
Environmental Baseline
Lighting: fluorescent tubes, color temperature measured at 3980 K. Intensity constant at 61 lux.
Ambient temperature: 17.8 °C. Humidity: 54 %.
Background sound: continuous low-frequency generator resonance at 34 Hz. Baseline reading 31 dB.
Air movement: none detected. Barometric pressure 1014.2 hPa on entry; 1009.6 hPa after 3.8 m of travel.
Spatial Observations
Gallery estimated 41 m long by 4.9 m wide by 3.6 m high. Laser measurement returns 28.4 m long by 5.7 m wide by 3.1 m high.
Floor: sealed concrete with green chemical-resistant coating. Coating thickness measures 1.9 mm. Surface remains uniform under repeated contact.
Walls: painted concrete block with three horizontal contact chamber arrays. Paint thickness measures 0.7 mm. Surface remains uniform under repeated contact.
Ceiling: exposed structural beams with five recessed lamp fixtures. Fixture count remains five after eleven visual inventories.
Repeating motif: every 6.2 m a contact chamber is mounted against the south wall. Chamber length measures 2.87 m. Inlet and outlet manifolds are identical across all chambers.
Anomalies
Visual inventory of contact chambers returns 3. Physical inventory returns 3. Measured ozone residual equals 0.0 mg/L while calculated residual concentration across the same chambers equals 2.4 mg/L.
Floor remains level under spirit level. Measured residual film on the lower wall panels slopes 1.9° toward the west wall. Slope reverses after 5 minutes of continuous observation without change in physical orientation.
Gallery pressure measures 1013 hPa while the external door indicator reads 1018 hPa. Seal integrity lights remain green.
Sound of residual ozone generator cycle arrives 2.1 seconds after the corresponding surface disturbance is detected. Delay increases by 0.28 s for every additional 1.5 m of distance from the entry door.
Humidity at mid-gallery remains 54 % while residual film forms on the chamber housings after 4 minutes of observation. Film disperses without measurable change in local humidity.
Local magnetic field strength measures 0.5 gauss at floor level and 1.9 gauss at 1.6 m height. Field direction reverses after 6 minutes without change in gallery state.
Ozone residual gauge needle count on the status array decreases by 4 over 9 minutes while measured generator output at all transducers remains 0.0 kg/h.
Surface of residual film on chamber housings exhibits electrostatic cling of 3.7 cm against vertical surfaces. Cling collapses after 38 seconds without change in measured surface charge.
Entity Notes
None observed.
At the 7.4 m mark a localized temperature drop of 3.8 °C occurs across a 1.4 m radius. Drop persists for 5 seconds then collapses. No visible source.
Exit / Continuity Status
Exit achieved through the same single steel door after 21 minutes of continuous observation. Exterior aperture on exit matches the interior measurement recorded on entry.
Residual effect: left glove retains a thin film of residual ozone condensate that disperses over 14 minutes without measurable mass change. Right glove remains clean.
Secondary timestamp on the log device advances 39 minutes while local elapsed time measures 21 minutes.