(*b*) AC,

DC,

&

RF

switchboard

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.

the

normal

indicated

frequency

(*d*) Sealed,

ruggedized

switchboard

(nominal design frequency). Accuracy

instruments 2 1/2, 3 1/2, and 4 1/2

should be 0.75 percent when

inches,

without

external

zero

checked at 77 F. 3. Reeds above

corrector, 2 percent, including zero

and below normal indicated frequency

check.

should resonate progressively in

(5) *Frequency meters.*

sequence when the frequency is

(*a*) The basic indicating meter in a

raised or lowered.

frequency meter test set should be

(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-

scale sensitivity only.

reference power level in watts, and *R*

(*b*) Self-contained decibel meters should

the resistance in ohms across which

be inspected for accuracy at both end

the meter is normally used.

The

scale calibration marks and at zero

meter should deflect to the specified

decibel. Defection will be obtained by

calibration mark when the required

applying ac voltage of 60-cycle

voltage within plus or minus 5 percent

frequency.

The voltage required

is applied.

should be obtained from a decibel

TAGO T41A

Integrated Publishing, Inc. |