TY  - RPRT
TI  - Letter Circular 925: testing of electrical instruments, meters and range-extending auxiliaries (superseding Letter Circular 475)
PY  - 1948
PB  - National Institute of Standards and Technology
CY  - Gaithersburg, MD
SN  - LCIRC 925
DO  - 10.6028/NBS.LCIRC.925
ER  -