The external oscillator is used to supply a test frequency. In this
method, the external oscillator is connected to the signal input
terminals as shown in Figure 4-1. The oscillator’s output
frequency is set to equal F (MAX) as indicated on the frequency
counter. Power is supplied from a DC source and the analog
output voltage is measured with a digital voltmeter.
1. The course range adjustment is accomplished by selecting a
switch position on a DIP switch located on the PCA-66 printed
circuit card. See Table 3-1 to determine required switch position
and set into switch as shown in Figure 3-3 for anticipated F MAX.
It is necessary to open the cover of the enclosure by removing two screws
on side of box and lifting cover. Two printed circuit cards are attached. The
“RANGE” Dip Switch may be programmed with a pen. Input power should
be removed during this step.
2. Zero Adjustment
a. The redual DC voltage at the output of the FLSC-28 may be
reduced to a low value (a few millivolts) with the aid of the
b. Apply the proper DC voltage to the power input. Turn the
input frequency off.
c. Turn the zero control CCW until no further decrease in the
output level is observed. Then turn the zero control CW
until the zero voltage starts to just increase.
3. Span Adjustment
a. Turn the input frequency on and adjust frequency to obtain
b. Adjust the span control to obtain the span voltage on the
output (5.000 Vdc)
4. Response Adjustment (Internal - located on the PCA-66
printed circuit card, see Figure 3-2)
a. The FLSC-28 is provided with an adjustable response trim
control which allows the user to control the response time
to obtain either fast response or minimum ripple.
b. To slow down response turn the response control CCW, to
speed up response turn the response control CW. The
maximum number of turns is 20 on this control. The control
will not be damaged if the end stops are reached and a
slipping action will be felt.
5. Sensitivity Adjustment
a. The sensitivity adjustment is generally left in the full CW
position and is adjusted in the final installation only when f else
pickup occurs during periods of no flow. See Sect. 3 Operation.