THRESHOLD COMPLEX EXPLORATION LOG
Designation / Log ID: 41-L38
Apparent Date/Time: 16 September 2026 / 09:14 (local) — secondary stamp reads 03:47 12 November 1983
Entry Method: Double steel door marked “D-15 DESALINATION MEMBRANE GALLERY – AUTHORIZED PERSONNEL ONLY”. Exterior clear aperture measures 1.82 m × 2.11 m. Interior aperture measures 1.97 m × 1.94 m on entry and 1.68 m × 2.29 m on exit.
Environmental Baseline
Lighting: fluorescent tubes, color temperature measured at 4120 K. Intensity constant at 53 lux.
Ambient temperature: 19.4 °C. Humidity: 61 %.
Background sound: continuous low-frequency pump resonance at 29 Hz. Baseline reading 27 dB.
Air movement: none detected. Barometric pressure 1012.7 hPa on entry; 1007.9 hPa after 4.2 m of travel.
Spatial Observations
Gallery estimated 34 m long by 5.3 m wide by 3.8 m high. Laser measurement returns 22.7 m long by 6.1 m wide by 2.9 m high.
Floor: sealed concrete with blue chemical-resistant coating. Coating thickness measures 2.1 mm. Surface remains uniform under repeated contact.
Walls: painted concrete block with four horizontal membrane skid arrays. Paint thickness measures 0.6 mm. Surface remains uniform under repeated contact.
Ceiling: exposed structural beams with six recessed lamp fixtures. Fixture count remains six after nine visual inventories.
Repeating motif: every 5.3 m a membrane skid is mounted against the north wall. Skid length measures 3.14 m. Feed and permeate manifolds are identical across all skids.
Anomalies
Visual inventory of membrane skids returns 4. Physical inventory returns 4. Measured permeate flow equals 0.0 m³/h while calculated residual conductivity across the same skids equals 184 µS/cm.
Floor remains level under spirit level. Measured residual film on the lower wall panels slopes 2.3° toward the east wall. Slope reverses after 6 minutes of continuous observation without change in physical orientation.
Gallery pressure measures 1013 hPa while the external door indicator reads 1017 hPa. Seal integrity lights remain green.
Sound of residual permeate drip arrives 1.9 seconds after the corresponding surface disturbance is detected. Delay increases by 0.31 s for every additional 1.6 m of distance from the entry door.
Humidity at mid-gallery remains 61 % while residual film forms on the membrane housings after 5 minutes of observation. Film disperses without measurable change in local humidity.
Local magnetic field strength measures 0.4 gauss at floor level and 2.1 gauss at 1.7 m height. Field direction reverses after 7 minutes without change in gallery state.
Membrane differential-pressure gauge needle count on the status array decreases by 5 over 11 minutes while measured feed pressure at all transducers remains 0.0 bar.
Surface of residual film on membrane housings exhibits electrostatic cling of 4.1 cm against vertical surfaces. Cling collapses after 41 seconds without change in measured surface charge.
Entity Notes
None observed.
At the 8.1 m mark a localized temperature drop of 4.2 °C occurs across a 1.6 m radius. Drop persists for 6 seconds then collapses. No visible source.
Exit / Continuity Status
Exit achieved through the same double steel door after 24 minutes of continuous observation. Exterior aperture on exit matches the interior measurement recorded on entry.
Residual effect: left boot sole retains a thin film of residual brine that disperses over 17 minutes without measurable mass change. Right boot remains clean.
Secondary timestamp on the log device advances 47 minutes while local elapsed time measures 24 minutes.