HP 431B Calibration Procedure page 15

Table 5. Range and tracking Performance Check (Without Power Meter Calibrator) - Continued
Test Test
Instrument Instrument
Switch Indication
Settings
3 3
10 10
10 8
10 6
10 4
10 2
Each time the TI RANGE switch is changed, turn the dc power
supply off and zero the TI meter.
(7) Repeat the technique in (5) and (6) above for the remaining positions of the TI
RANGE switch. If both a 200-ohm and 100-ohm thermistor mount is available, perform (1)
through (6) above for both mounts.
b. Adjustments. Adjust R1 through R14 (fig. 3) as appropriate for model 431C. No
adjustment can be made on model 431B.
12. Oscillator Frequency
Do not perform the oscillator frequency check if all parameters
in paragraphs 8 through 11 above are within tolerance.
a. Performance Check
(1) On model 431C, connect frequency counter (A4) to the positive end of C18 (fig. 1)
and ground, using cable (B4). On model 431B, connect the counter to the positive end of
C125 (fig. 2) and ground.
(2) Connect 200-ohm thermistor mount (A8) to the TI and terminate the mount
with termination (B6).
(3) Set the TI MOUNT RES switch to 200Ω.
(4) If the frequency counter does not indicate between 9,990 and 10,010 Hz for
model 431C, perform b(1) below.
indicate between 10,025 and 10,275 Hz, perform b(2) below.
Dc Voltmeter Indications (vdc) (Readings
for Model 431B are in Parenthesis)
200-Ohm Mount
Min Max
7.67 7.83
(7.52) (7.98)
14.00 14.28
(13.7) (14.6)
12.52 12.78
(12.3) (13.0)
10.84 11.06
(10.6) (11.3)
8.85 9.03
(8.67) (9.21)
6.26 6.38
(6.13) (6.51)
NOTE
NOTE
For model 431B, if the frequency counter does not
100-Ohm Mount
Min Max
10.84 11.06
(10.6) (11.3)
19.80 20.20
(19.4) (20.6)
17.71 18.07
(17.4) (18.4)
15.34 15.64
(15.0) (16.0)
12.52 12.78
(12.3) (13.0)
8.85 9.03
(8.67) (9.21)
TB 9-6625-086-35
Adjustments for Model
431C (fig. 3)
200-Ohm 100-Ohm
Mount Mount
R9 R6
R8 R7
11