- National Institute of Standards and Technology (NIST), Gaithersburg MD (2007-2010)
- MEMS Measurement Science and Standards Project Leader
- Sequoyah Technology LLC (STLLC), Olney MD (1994-2007)
- Consulting and contract work for various organizations
- National Bureau of Standards (NBS, 1964-1998) and National Institute of Standards and Technology (NIST, 1988-1994)
- Electro Optical Radiometry Group Leader (1972-1980)
- Quantum Radiometry Group Leader (1980-1986)
- Semiconductor Sensors Project Leader (1986-1990)
- NBS-Census Optical Characterization Recognition Performance Project (1990-1994)
- BS in Theoretical and Applied Science
- PhD in Electrical Engineering, University of Alberta, 1992
Dr. Geist is an electrical engineer in the Nanoscale Metrology Group in the Engineering Physics Division of the Physical Measurement Laboratory (PML) at the National Institute of Standards and Technology (NIST). Dr. Geist is a moving target who maintains a low profile. He has worked as a technician, physicist, electrical engineer, mathematician, and reluctant manager during his career. Dr. Geist was a cofounder of the NBS Electro Optical Radiometry and Quantum Radiometry Groups. These two groups played a major role in pioneering virtually all of the advances that are the basis of modern high-accuracy radiometry in the visible and near-visible spectral region. These advances include electrically-calibrated pyroelectric radiometers, amplitude-stabilized lasers, silicon photodiode self-calibration and high-accuracy spectral response interpolation, cryogenic radiometers, and silicon-photodiode detector-trap configurations. Much of the measurement technology developed by these NBS Groups was commercialized by a number of different companies, and most of it is still on the market today.
Dr. Geist's current research interests include measurement science and standards for MEMS sensors and actuators and bioelectronic chips. Dr. Geist has over 100 publications, 7 issued patents, and is the author of the articles Photometry and Radiometry in the McGraw-Hill Encyclopedia of Science and Technology.