Simpson 260 - Page 7

FOREWCHRD
Because of the similarities in appearance
and operation between the Model 260 Series III
and Series IIIS, and the Model 270 Custom Series
and Custom IIIS, it has been found expedient to
produce а single Operator's Manual for all
Models.
Throughout the text, where the informa-
tion applies generally to all four, we refer >
simply to "the instrument". Where necessary,
we distinguish between the "Model 260" (mean-
ing either the Series III or the Series IIIS)
and the "Model 270" (meaning either the Custom
Series or the Custom IIIS).
The significant difference between the
Model 260 Series III and tne Series IIIS lies
in the use of а self-shielding (S) movement in
the latter, which protects it from the influence
of external fields. This also ensures that the
leakage field from the movement is so low as to
produce negligible disturbance of sensitive in-
struments operated in the near vicinity. The
above applies equally to the Model 270 Custom
IIIS, distinguishing it from the Model 270
Custom Series.
x + 3 3 +
The Model 260 is а rugged, reliable all-
purpose measuring instrument. It is used for
measuring AeCe and DeCe voltages, D.C. currents,
resistances, volume levels, and audio output
voltages, Protective fusing and spring-backed
jewels provide protection against the hazards
of day-to-day use,