For all measurement systems, proper wiring, noise shielding, and grounding practices are essential to achieving high accuracy analog measurements. Assuring proper connectivity and wiring should be the first step when designing a high accuracy measurement system. To assist in designing your system we recommend visiting the Measurement Fundamentals Developer Zone article.
CompactRIO systems are designed to provide both high-accuracy measurements and industrial ruggedness. From the factory, each analog I/O module is calibrated against a NIST-traceable precision source. Accuracy is guaranteed for at least one year after calibration and each module can be re-calibrated through-out its life. Because CompactRIO systems are also designed for applications with high shock and vibration, the system avoids the use of failure-prone mechanical cooling components such as rotating fans. While CompactRIO system components can safely be used together across the rated temperature range, analog module accuracy is sensitive to heat. The high-performance processors and FPGAs used in the cRIO-9022 or 9024 and cRIO-911x can contribute additional heat to the system.
To help you achieve the specified analog module accuracies for cRIO systems containing a cRIO-9022 or cRIO-9024 and/or cRIO-911x we recommend you adhere to the following guidelines (note exceptions for NI 9211 and NI 9225 in the "Module Exceptions" section of this document.