TB 9-6695-293-50
e. Wideband Flatness Calibration
NOTE
Paragraphs b through d above comprise the verification test
for the wideband option. Paragraph e below is the flatness
calibration procedure. Performance of e below is only required
if an out-of-tolerance condition exists in b and d above or upon
initial calibration of wideband option. In both cases
paragraphs a and c above must be completed prior to e below
in order to establish, or characterize, voltage accuracies at 1
kHz (c above must be in tolerance prior to performing e below).
(1) Connect equipment as shown in figure 13.
(2) Set rear panel CALIBRATION NORMAL/ENABLE switch to ENABLE.
(3) Press the WBND pushbutton on the ac measurement standard.
(4) Call up the TI wideband flatness calibration routine by pressing the soft key
sequence SETUP MENUS, CAL, CAL (again) and WIDEBAND FLAT.
(5) Enter the present ambient air temperature as prompted and press ENTER;
press ENTER again.
(6) Press OPERATE pushbutton. Wideband flatness calibration starts with a
nominal 3 V at 1 kHz output. If TI displayed value is not 3.00000 V, use output adjustment
knob to enter this value. When this is completed, the Error indication should indicate 0.0
ppm.
(7) When the ac measurement standard settles to a reading, press the SET REF
soft key. (This is the 3 V reference value from which all 3 V frequencies will be compared.)
(8) Press ENTER pushbutton; the frequency will advance to the next value.
(9) Adjust the TI output adjustment knob to bring the ac measurement standard
error display to indicate 0 PPM (30 PPM); then press ENTER pushbutton.
(10) Repeat (9) above for each frequency displayed through 30 MHz.
(11) Press the CLEAR REF WBND soft key on the ac measurement standard. The
TI wideband output should nominally be 1 V, 1 kHz. If TI displayed value is not 1.00000 V,
use output adjustment knob to enter this value. When this is completed, the Error
indication should indicate 0.0 ppm.
(12) When the ac measurement standard settles to a reading, press the SET REF
soft key. (This is the 1 V reference value from which all 1 V frequencies will be compared.)
(13) Press ENTER pushbutton; the frequency will advance to the next value.
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