Thermal Converter Calibration - HP 11049A Operating And Service Manual

Model 11049A
Adjust oscillator output so that null meter in­
dication is half way between indications re­
corded in steps d and e. This sets oscillator
output to 1 volt rms.
g. Record error of instrument under test.
DO NOT CHANGE OSCILLATOR FREQUENCY
RANGE WITHOUT FIRST LOWERING OSCIL­
LATOR OUTPUT. SWITCHING TRANSIENTS
MAY DESTROY THERMOELEMENT.
h. Adjust frequency to next desired test frequency.
Then readjust oscillator output for same in­
dication as in step f. Record error of instru­
ment under test.
i. Repeat steps g through i for each test fre­
quency deSired.
22. MAINTENAN CE.

23. THERMAL CONVERTER CALIBRATION.

24. Figure 6 shows the setup for calibrating a thermal
converter to an NBS calibrated reference thermal con­
verter. With this setup, the thermal converter can
±O.
be calibrated to"\vithin 005% of the reference thermal
converter. The following steps describe the calibration
procedure.
a. Sct test oscillator and both reference supply
outputs to minimum.
NBS REFERENCE
THERMAL CO NVERTER
�,,',
U NDER TEST
�'""" '"",'"'�
Figure 6. Thermal Converter Calibration
b. Connect both thermal converters, both ref­
erence supplies, both null meters, and the
test oscillator as shown in Figure 6. Keep
connections to thermal converters as short as
possible.
Page 6
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