The Model 4540 gauges can display measurement results in
either SI (metric) units or English units. Also, HM-181 of 49 CFR
changes the standard units of radioactivity in the United States
from the English unit of curies (Ci) to the SI unit of becquerel
(Bq). This requires the shipper to convert the activity on the Bill
of Lading from curies to becquerels (GBq). Until everyone is
accustomed to the SI units, it is permitted to follow the SI units
with the English units in parentheses to clarify the description
[for example: 1.48 GBq (40 mCi)].
To help convert from English units to SI units, the following
provides SI conversion factors for common English units
relevant to the gauge.