1-4
IM CA500-01EN
Resistance
This function generates the following resistances.
Range
Source Range
Notes
400Ω
0.00 Ω ~ 440.00 Ω
Allowable measurement current: 0.1 mA to 3 mA
4000Ω
0.0 Ω ~ 4400.0 Ω
Allowable measurement current: 0.05 mA to 0.6 mA
Resistance Source Method
A pseudo-resistance (R=V/I) is sourced by generating a voltage (V=R×I) corresponding to the
resistance [R] set on the instrument across the output terminals for the current for measuring
resistance [I] supplied to the device to be calibrated such as a resistance measuring
instrument and RTD thermometer.
Therefore, this instrument can be used only for instruments that measure pseudo-resistance
using a current for measuring resistance.
How to Source Accurately
• When measuring resistance using a two-wire system, use lead cables with low resistance.
Because the source resistance is calibrated without including the voltage drop of the
leaked cables, the lead cable resistance will result in error.
• To source the resistance accurately, use of the three-wire system or four-wire system.
CA500/CA550
Black
Red
H
Calibration target
(three-wire
measuring instrument)
L
L’
1.2 Source Function
