Keithley 2500 - Introduction; Environmental Conditions; Temperature and Relative Humidity; Warm-Up Period

2-2 Calibration Model 2500 Service Manual
Introduction
Use the procedures in this section to calibrate the Model 2500 Dual Photodiode Meter.
These procedures require accurate test equipment to supply precise currents and measure
accurate DC voltages. Calibration can be performed either from the front panel or by send-
ing SCPI calibration commands over the IEEE-488 bus or RS-232 port with the aid of a
computer.
WARNING The information in this section is intended for qualified service person-
nel only. Do not attempt these procedures unless you are qualified to do
so. Some of these procedures may expose you to hazardous voltages.
Environmental conditions
Temperature and relative humidity
Conduct the calibration procedures at an ambient temperature of 65-82°F (18-28°C) with
relative humidity of less than 70% unless otherwise noted.
Warm-up period
Allow the Model 2500 to warm up for at least one hour before performing calibration.
If the instrument has been subjected to temperature extremes (those outside the ranges
stated above), allow additional time for the instrument’s internal temperature to stabilize.
Typically, allow one extra hour to stabilize a unit that is 50°F (10°C) outside the specified
temperature range.
Allow the test equipment to warm up for the minimum time specified by the manufacturer.
Line power
The Model 2500 requires a line voltage of 100V / 120V / 200V / 240V (depending on line
voltage setting) at line frequency of 50 or 60Hz. The instrument must be calibrated while
operating from a line voltage within this range. Make sure the line voltage setting seen
through the small window in the rear panel power module is at the required setting. If not,
change the setting as covered in Section 3.