C Series modules are designed to provide high-accuracy measurements. From the factory, most analog I/O modules are 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. While C Series system components can safely be used together across the rated temperature range, analog module accuracy is sensitive to heat.
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 White Paper article.
Calculations for C Series maximum accuracy specifications assumes a worst case range of component tolerances and a full thermal load on the system (maximum processor and FPGA usage, and a chassis fully loaded with high power modules). Many C Series analog modules also provide specifications for typical accuracy. Because most systems are not subjected to such high thermal loads and extreme component tolerance, NI also provides typical accuracies, in addition to maximum accuracies, to help guide you on the accuracy that can be expected from common configurations. While typical specifications are not guaranteed, most systems mounted and oriented in accordance with the guidelines above will meet the published typical specifications. C Series systems not adhering to the guidelines may also meet the published typical specifications, but are significantly less likely to do so.