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Ted Doiron, identified as Theodore D. Doiron in NIST's official publication record, is a dimensional metrology researcher and coauthor with John S. Beers of The Gauge Block Handbook by Ted Doiron and John S. Beers. The preface uses Ted Doiron and attributes substantial changes to the handbook's measurement-assurance program to the author abbreviated TD.^[ref]

The scientific challenge is to obtain a reproducible length from a material artifact under changing environmental and measurement conditions. Thermal expansion is a particularly clear example. For a small temperature change,where $\alpha$ is the linear expansion coefficient. An original example with $L(T_0)=100\mathrm{mm}$, stipulated $\alpha =11.5\times 10^{-6}{\mathrm{K}}^{-1}$ and $T-T_0=0.1\mathrm{K}$ gives a length increase $0.115\mu \mathrm{m}$. A small temperature difference can therefore matter when comparing precision gauge blocks.

Even a shared temperature does not cancel every thermal effect. For two equal nominal lengths with different expansion coefficients, the first-order differential change isUsing $L=100\mathrm{mm}$, coefficient difference $1\times 10^{-6}{\mathrm{K}}^{-1}$ and common offset $0.2\mathrm{K}$ gives $20\mathrm{nm}$. This gauge-block thermal mismatch survives a simple subtraction even though both blocks have reached the same temperature. A temperature difference between the blocks introduces another contribution.

The handbook treats temperature corrections and their control alongside comparison procedures and measurement assurance.^[ref] A useful experiment compares the corrected result over controlled environmental changes and checks an independent measurement standard, rather than equating a stable display with an accurate physical length. The examples above are illustrative calculations, not an attributed material dataset or a claim about current NIST instrument performance.