Research note / Cycle 012
Two readings of the same stillness
A loaned passive comparator shares most of the first-hour change; the local target still cannot establish its own stationarity.
Another instrument, a limited loan
The surrogate-strip bench needs to distinguish extension from movement in its supports. The first commissioning hour supplied only a powered head display. Reed and Voss request a passive comparator from North Quay Instrument Cooperative on December 27, receive a loan offer the next day, and collect NQ-17 with its stand on December 29. Voss holds custody; the loan ends January 8.
NQ-17 has nominal one-micrometre divisions. No independently verified calibration or uncertainty accompanies the loan. On December 30 its separate stand is placed on the intake table with its contact observing the same unloaded local target as KIS-61. The original head and bracket remain together. No strip, force system or commanded travel is introduced.
Keep the two starting readings
The KIS-61 display begins at 3 micrometres and the comparator at 125 micrometres. Neither display is tared during the log. The table reports changes from those retained starting values at zero, ten, thirty and sixty minutes after the head is powered. KIS-61 changes by 0, 8, 10 and 10 micrometres; NQ-17 by 0, 7, 9 and 9. Their arithmetic difference is 0, 1, 1 and 1.
These are performed observations in a new session, not a reconstruction or correction of the earlier 0/9/11/11 display log. Most of the new change is shared between channels. That observation is compatible with target or support motion and shared environmental response; it does not determine a thermal cause or prove either instrument is stable.
Separate origin does not remove a shared target
The passive comparator comes from a different custody chain and uses a different readout mechanism. It still shares the target and table environment. The one-micrometre difference is not an uncertainty estimate, a calibrated strip extension or a passed six-micrometre return test. Nominal divisions do not establish measurement accuracy.
Voss permits this unloaded comparison only. Full bidirectional coverage at the existing 1000-micrometre grid, reference geometry, environmental bounds and post-transport review remain open. The 25-micrometre budget and six-micrometre return allowance stay unchanged. The loan gives the next comparison a deadline without granting acceptance.
Results at a glance
| Minutes after KIS-61 power-on | KIS-61 change (um) | NQ-17 change (um) | Arithmetic difference (um) |
|---|---|---|---|
| 0 | 0 | 0 | 0 |
| 10 | 8 | 7 | 1 |
| 30 | 10 | 9 | 1 |
| 60 | 10 | 9 | 1 |