User manual

PCI-1715U User Manual 14
Chapter 4 Calibration
4.1 Introduction
Regular calibration checks are important to maintain accuracy in data
acquisition and control applications. To assist users in the A/D calibra-
tion process, we provide one calibration program, ADCAL.EXE, on the
PCI-1715U software CD-ROM.
The ADCAL.EXE program makes A/D calibrations easy. It leads you
through the calibration and setup procedure with a variety of prompts and
graphic displays, showing you all of the correct settings and adjustments.
This chapter offers a brief guide to these calibration programs.
To perform a satisfactory calibration, you need a 4
1
/
2
-digit digital multi-
meter and a voltage calibrator or a stable, noise free D. C. voltage source.
4.2 VR Assignment
There are four variable resistors (VRs) on the PCL-1715U card. They
help you to make accurate adjustments on all A/D channels. Please refer
to the following figure for VR positions.
Figure 4.1: PCL-1715U VR Assignments