Verification Limits; Example Reading Limit Calculation; Calculating Resistance Reading Limits; Restoring Factory Defaults - Keithley 2701 Service Manual

Model 2701 Service Manual
Verification limits
The verification limits stated in this section have been calculated using only the Model 2701
one-year accuracy specifications, and they do not include test equipment uncertainty. If a
particular measurement falls slightly outside the allowable range, recalculate new limits based
on both Model 2701 specifications and pertinent calibration equipment specifications.

Example reading limit calculation

The following is an example of how reading limits have been calculated. Assume you are
testing the 10V DC range using a 10V input value. Using the Model 2701 one-year accuracy
specification for 10V DC of ± (30ppm of reading + 5ppm of range), the calculated limits are:
Reading limits = 10V ± [(10V × 30ppm) + (10V × 5ppm)]
Reading limits = 10V ± (0.0003 + 0.00005)
Reading limits = 10V ± 0.00035V
Reading limits = 9.99965V to 10.00035V

Calculating resistance reading limits

Resistance reading limits must be recalculated based on the actual calibration resistance
values supplied by the equipment manufacturer. Calculations are performed in the same
manner as shown in the preceding example, except, of course, that you should use the actual
calibration resistance values instead of the nominal values when performing your calculations.
For example, assume that you are testing the 10kΩ range using an actual 10.03kΩ
calibration resistance value. Using Model 2701 one-year 10kΩ range accuracy of ± (100ppm of
reading + 6ppm of range), the calculated reading limits are:
Reading limits = 10.03kΩ ± [(10.03kΩ × 100ppm) + (10kΩ × 6ppm)]
Reading limits = 10.02894kΩ to 10.03106kΩ

Restoring factory defaults

Before performing the verification procedures, restore the instrument to its factory defaults
as follows:
1.
2.
Press SHIFT and then SETUP. The instrument will display the following prompt:
RESTORE: FACT.
Using either range key, select FACT, then restore the factory default conditions by
pressing ENTER.
Performance Verification 1-5