Guildline 6530 Series, Руководство оператора

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Section 3
OM6530-C1-00
19 November, 2019
3-6
Step 3) Measure the unknown resistor on the 6530. For this example, the reference resistor is a 1
GΩ resistor. Again, the measurement should run for 300 samples keeping the last 50 for
determination of standard deviation and mean. The optimum measurement parameters for a 1
GΩ resistor is Test Voltage of 10 V using the 2700 pF capacitor and 10 V threshold.
Step 4) The actual value unknown resistance can then be calculated using the resistance ratio of
the two measurements multiplied by the known reference resistance value. Also, the uncertainty
can be calculated by combining the uncertainties of the reference resistor, the 6530 bridge
specification
Using the following equations (1) and (2) defined earlier in terms of our 100 MΩ to 1 GΩ
example we will use the following results:
Rxm = Measured UUT 1.0000089 GΩ
Rsc = Reference calibrated value 100.0017 MΩ
Rsm = Measured reverence value 100.0023 MΩ
Rxc = Rsc * Rxm / Rsm
= 100.0017 MΩ * 1.000089 GΩ / 100.0023 MΩ
= 100.0017M * 1.000089 GΩ / 100.0023 MΩ
= 100.0017 MΩ * 100.0066
= 1.000083 GΩ
Simplified uncertainty calculations are as follows:
URxm = 4.756 ppm (2 times the standard deviation of UUT)
URsc = 10 ppm reference uncertainty (typically k = 2)
URsm = 2.013 ppm (2 times the standard deviation of UUT)
Umeter = 20 ppm (larger of bridge specifications for the two resistances measured
using a 6530)
URxc = (URsc
2
+ URsm
2
+ URxm
2
+ Umeter
2
)
= (10
2
+ 2.013
2
+ 4.756
2
+ 20
2
)
= (10
2
+ 2.013
2
+ 4.756
2
+ 20
2
)
= (100 + 4.052 + 22.620 + 400)
= 526.672
= 22.949 u /