Abstract: Methods of producing a plurality of spectroscopic measurement devices, comprising producing a calibration model that includes the expected range of measurement variation across the plurality of devices; producing the devices; installing the calibration model on each device. Most standard methods focus on ways to reduce the number of replicate samples that are required to be taken on a given instrument or class of instruments. The present methods can reduce that number to zero by anticipating the expected range of instrument variation in manufacturing in the field. This can be important when measuring live biological samples as it is impractical to maintain standard humans, cells, etc. This is in contrast to measurements on dry agricultural products where a standard, sealed dry sample can be maintained for months/years when required.

Abstract: An apparatus and method for non-invasive determination of hydration, hydration state, total body water, or water concentration by quantitative spectroscopy. The system includes subsystems optimized to contend with the complexities of the tissue spectroscopy, high signal-to-noise ratio and photometric accuracy requirements, tissue sampling errors, calibration maintenance, and calibration transfer. The subsystems include an illumination subsystem, a tissue sampling subsystem, a spectrometer subsystem, a data acquisition subsystem, a computing subsystem, and a calibration subsystem.

Abstract: An apparatus and method for non-invasive determination of hydration, hydration state, total body water, or water concentration by quantitative spectroscopy. The system includes subsystems optimized to contend with the complexities of the tissue spectroscopy, high signal-to-noise ratio and photometric accuracy requirements, tissue sampling errors, calibration maintenance, and calibration transfer. The subsystems include an illumination subsystem, a tissue sampling subsystem, a spectrometer subsystem, a data acquisition subsystem, a computing subsystem, and a calibration subsystem. The system can include a plurality of measurement devices, configured to communicate with each other and with a remote receiver or centralized server. The invention contemplates novel ways to arrange various subsystems and to provide operability and communication among them.