A go-between device that lets two standards be compared when they cannot sit side by side, usually because they live in different labs. Zener voltage references, standard resistors and travelling weight sets are typical: they are measured at one site, shipped and measured at the other. Their worth comes from short-term stability and robustness in transport rather than absolute accuracy, and transport effects become a line in the budget.
The transfer standard rides in the back seat on its battery pack, it does not go in the box truck.
Transfer standards are judged on stability and how well they survive shipping; a less accurate device that holds still beats a better one that wanders.
Also heard as
- travelling standard
- transport standard
Related terms
Reference standard
A lab's highest-level standard for a quantity, used only to calibrate other standards and never for routine work.
Round robin
An interlaboratory comparison in which one artifact or sample travels from lab to lab to be measured by each.
Proficiency testing
Judging a lab's performance by having it measure circulated items and scoring its results against a reference value.
Stability
The ability of an instrument or standard to hold its calibrated values as the weeks and months pass.
Primary standard
A standard that gets its value straight from the unit definition, not from calibration against another standard.