We constructed a digitally programmable capacitance standard by modifying a commercial temperature-stabilized 100 pF capacitance standard which consists of 23 binary-weighted capacitor elements on a single fused-silica disk. The variable capacitor can be programmed through a computer from 0.0001154 pF to 113.0464964 pF with a resolution smaller than 0.0001154 pF over the entire range. Using proper combinations, we also demonstrate a method to calibrate the 23 capacitor elements against a 10 pF capacitance standard.
and Lee, L.
A digitally programmable capacitance standard, Review of Scientific Instruments, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=31455
(Accessed June 8, 2023)