| In 1908, the Model A meter was replaced by an improved version, the Model E.
The Model E incorporated a more compact case, a 4-dial register, and a redesigned starting coil (light-load adjustment). Model E meters with serial numbers beyond 150,000 have no additional information printed on the register except for "Kilowatt Hours" in conformance with industry standards going into effect around this time.
The EA meter was an improved version of the E with the coils arranged astatically to make the meter immune to external stray electrical fields.
In 1910, the 2.5, 5, and 10 ampere ratings were replaced with a more compact version that fit better to the smaller DC services these were built for. |