Fluke 9500B - Page 227

Section 9: Verifying the Model 9500B Accuracy Specification 9-17
Final Width = 215mm
Verif. 4955 Resistance Calculated Absolute 4955 Resistance
Point. Switch Value Measured Tolerance Limits Switch Value Measured
Position by DMM Lower Higher Position by 9500B
Op. 3 (b) (Rref) (L lim) (H lim) Op. 7 (a) (Rmeas)
RES1 Ref 1M Ω Meas 1M Ω
RES2 Ref 50 Ω Meas 50 Ω
Table 9.8.5.1 Load Resistance Measurement Verification
Please copy the following table. Enter the measurements on the copy as described in the procedure:
9.8.5.5 Verification Procedure
Copy the table: 9.8.5.1. Follow the correct sequence of verification points as shown on the table, and carry out the following operations (1) to
(10) at each verification point.
6. Calculate the lower and higher absolute tolerance limit values:
Lower limit: (L lim) = R ref - (R ref x 0.001)
Higher limit: (H lim) = R ref + (R ref x 0.001)
Enter L lim and H lim into the appropriate columns in Table 9.8.5.1.
7. If using the Model 4955 Calibration Adaptor:
a) Set the Model 4955 Calibration Adaptor switch as shown in
Table 9.8.5.1.
b) Reconnect the Active Head output BNC to the Model 4955
input.
8. If not using the Model 4955, disconnect the load resistor from the
DMM, and reconnect it to the 9500B Active Head output BNC.
9. Press the ON key to turn the 9500B output on.
10. Using the 9500B, take a Resistance measurement and note the result
(
R meas) in Table 9.8.5.1.
11. 9500B Set OUTPUT OFF.
1. Verification Points Refer to Table 9.8.5.1.
2. 9500B Ensure that OUTPUT is OFF.
3. If using the Model 4955 Calibration Adaptor:
a) Ensure that the Active Head output BNC is disconnected from
the Model 4955 input.
b) Set the Model 4955 Calibration Adaptor switch as shown in
Table 9.8.5.1.
4. If not using the Model 4955, set up external circuitry to measure the
appropriate load resistor (4-wire connection), with the 9500B
Active Head output BNC disconnected.
5. DMM Set to the appropriate Resistance measurement
range, take a Resistance measurement and note the
result (R ref) in Table 9.8.5.1.
Note: Make sure to allow for any settling time of
the external measuring instrument.