1-4
Performance Verification
Recommended test equipment
summarizes recommended verification equipment and pertinent specifications.
You can use alternate equipment as long as that equipment has specifications at least as
good as those listed in
. Keep in mind, however, that test equipment uncertainty
will add to the uncertainty of each measurement. Generally, test equipment uncertainty
should be at least four times better than corresponding Model 2500 specifications.
NOTE
The Calibrator/Source listed in
does not quite meet the recommended
four times better uncertainty for 19
µ
A to 19mA output values. Factory calibra-
tion uses a transfer standard technique that yields uncertainties better that 4:1
for all calibration points.
Verification limits
The verification limits listed in this section have been calculated using only the
Model 2500 one-year accuracy specifications, and they do not include test equipment
uncertainty. If a particular measurement falls outside the allowable range, recalculate new
limits based on Model 2500 specifications and corresponding test equipment
specifications.
Table 1-1
Recommended verification equipment
Description
Manufacturer/Model
Specifications
Uncertainty
Ratio
4
Calibrator/Source
Keithley 263
DC Current
1
1.9nA:
19nA:
190nA:
1.9
µ
A:
19
µ
A:
190
µ
A:
1.9mA:
19mA
2
:
±0.068%
±0.068%
±0.04%
±0.03%
±0.03%
±0.03%
±0.03%
±0.04%
15:1
6:1
7.6:1
6.75:1
3.4:1
3.4:1
3.4:1
2.6:1
Digital Multimeter Keithley 2001
DC Voltage
3
20V:
200V:
±22ppm
±30ppm
45:1
33:1
1
90-day accuracy specifications at specified output for passive V/R amps mode except as noted.
2
90-day specifications at 19mA output for active amps mode.
3
90-day full-range accuracy specifications.
4
Ratio between test equipment uncertainty and Model 2500 uncertainty.
Summary of Contents for 2500
Page 2: ...Contains Calibrating and Servicing Information Model 2500 Dual Photodiode Meter Service Manual...
Page 11: ......
Page 13: ......
Page 15: ......
Page 16: ...1 PerformanceVerification...
Page 28: ...2 Calibration...
Page 56: ...3 RoutineMaintenance...
Page 59: ...3 4 Routine Maintenance Model 2500 Service Manual...
Page 60: ...4 Troubleshooting...
Page 74: ...5 Disassembly...
Page 81: ...5 8 Disassembly Model 2500 Service Manual...
Page 82: ...6 ReplaceableParts...
Page 93: ...6 12 Replaceable Parts Model 2500 Service Manual...
Page 94: ...A Specifications...
Page 98: ...B CalibrationReference...
Page 108: ...C CalibrationProgram...
Page 117: ......
Page 119: ......
Page 120: ......
Page 121: ...Keithley Instruments Inc 28775 Aurora Road Cleveland Ohio 44139 Printed in the U S A...