Autocalibration Provides Improved Performance
Autocalibration provides much better accuracy than manual calibration and also reduces maintenance costs. Autocalibration means that the board contains circuitry to support calibration without any user intervention. Usually the calibration procedure is managed by driver software, which controls the autocalibration circuitry on the board, determines the best settings, and stores them on the board. Autocalibration can be performed whenever desired and as often as desired by simply executing some driver function calls. This way the board stays in calibration over its entire operating life with zero maintenance cost.
High quality A/D boards offer autocalibration to provide better performance. Usually there is some price premium for autocalibration. However, because no user access is required for calibration, the increased cost of the autocalibration feature is more than compensated by the savings in maintenance costs over the life of the board.
Multi-range autocalibration provides even better accuracy. Most autocalibrating A/D boards have multiple input ranges, yet they offer only a simple one-voltage one-input-range calibration. Again, this leaves open the possibility for errors when your application uses a different input range than the one in which the board was calibrated. Errors between input ranges on a typical programmable gain amplifier may be as high as 0.2 percent.
To eliminate these errors, multi-range autocalibration provides multiple reference voltages and a way to store calibration settings for each input range. This way, the board has the highest possible accuracy in all operating conditions: time, temperature, and input range. Multi-range autocalibration is the method of choice for an embedded application requiring accurate performance in an environment with wide temperature swings.