tested for full-scale sensitivity only.
instruments 2 1/2 inches and 3 1/2
(b) Self-contained frequency meters of
inches, 2 percent.
the 60-cycle and 400-cycle reed type
(c) Rectifier type instruments 2 1/2 inches
should be inspected for accuracy at
and 3 1/2 inches, 5 percent.
(nominal design frequency). Accuracy
instruments 2 1/2, 3 1/2, and 4 1/2
should be 0.75 percent when
checked at 77 F. 3. Reeds above
corrector, 2 percent, including zero
should resonate progressively in
(5) Frequency meters.
sequence when the frequency is
(a) The basic indicating meter in a
raised or lowered.
(6) Decibel meters.
conversion chart or by applying the
(a) The basic indicating meter in a decibel
following formula: V = P X R in which
meter test set should be tested for full-
V is the required voltage, P the zero
scale sensitivity only.
reference power level in watts, and R
(b) Self-contained decibel meters should
be inspected for accuracy at both end
the meter is normally used.
meter should deflect to the specified
decibel. Defection will be obtained by
applying ac voltage of 60-cycle
voltage within plus or minus 5 percent
The voltage required
should be obtained from a decibel