Keithley 2520, Service Manual, Page: 35 / 137

Model 2520 Pulsed Laser Diode Test System Service Manual Calibration 2-5
Calibration cycle
Perform calibration at least once a year to ensure the unit meets or exceeds its
specifications.
Recommended calibration equipment
Table 2-1 lists the recommended equipment for the calibration procedures. You can use
alternate equipment as long that equipment has specifications at least as good as those
listed in the table. For optimum calibration accuracy, test equipment specifications should
be at least four times better than corresponding Model 2520 specifications.
Table 2-1
Recommended calibration equipment
Description Manufacturer/Model Specifications
Calibrator Fluke 5700A
1
DC Voltage: 5V:
10V:
±5ppm
±5ppm
Digital
Multimeter
Keithley 2001
2
DC Voltage:
DC Current:
Resistance:
20V:
2mA
20mA
200mA
20
Ω
200
Ω
2k
Ω
±22ppm
±320ppm
±320ppm
±320ppm
±59ppm
±43ppm
±37ppm
Resistors
3
1.2 to 1.6
Ω
, 2W, ±5%
4
10 to 15
Ω
, 2W, ±5%
4
10
Ω
, 0.5W, ±1%
10
0Ω
, 0.5W, ±1%
200
Ω
, 2W, ±1%
400
Ω
, 1W, ±1%
1k
Ω
, 0.5W, ±1%
2k
Ω
, 0.25W, ±1%
Temperature
coefficient =
20ppm/°C for
all resistors.
1. 90-day accuracy specifications of lowest usable range for specified output.
2. 90-day full-range accuracy specifications.
3. Characterize resistors to within ±100ppm using 4-wire ohms function of digital multimeter before use.
4. Use only non-inductive metal film or bulk metal resistors.
Resistor characterization
The precision resistors listed in Table 2-1 should be characterized to within ±100ppm
using the 4-wire ohms function of the digital multimeter before use. Use the characterized
values when performing the calibration procedure.