Research note / Cycle 014
Two ends of the strip
The next reference specification separates endpoint motion, support motion and instrument error before another loan is requested.
Draw the observation before borrowing the instrument
A tether-material bench must measure how much a strip lengthens. The last comparator session showed two instruments following the same local target; it could not establish whether that target supplied a stationary reference. NQ-17 has returned to North Quay. Reed and Voss spend January 11–13 specifying what another comparison would need to observe.
The new dossier distinguishes the two ends of a future strip, the support path behind each observation and the readout error on each channel. It is a geometry study on paper. The existing KIS-61/KB-2 assembly remains at Meridian; no new mount, loan, loaded sample or measurement is introduced.
A subtraction with conditions
Call the endpoint readings A and B. Their difference can represent extension only after accounting for differential support motion and differential readout error. Equal translation of the two support paths cancels in B minus A; unequal motion does not. The equal-motion assumption must be tested rather than supplied by the appearance of two instruments.
The next request must describe accessible endpoint geometry, mounting constraints, both travel directions over the retained 1000-micrometre grid, and documented range and uncertainty. A proposed reference must contribute to the 25-micrometre displacement budget and the separate six-micrometre return assessment. Neither scale divisions nor an unloaded agreement establishes that contribution.
What the request can now ask
The dossier is ready for a technical availability inquiry after the observation geometry is reviewed. It asks for calibration documentation and usable coverage, rather than another unspecified loan. No inquiry has been sent and no lender has promised equipment. Differential support motion, alignment and the uncertainty allocation remain open.
This interval completes a design decision. Material loading and bench acceptance remain withheld. The earlier records keep their original readings and the January 8 return retains its full effect.