I'm using the NI USB 6259 with type E thermocouples and LabVIEW Signal Express to measure temp. avgs over a period of time. There seems to be a slow rate of response between the thermocouple and the board -- for example, if I pinch the thermocouple, and then release it, the temperature will keep rising for a solid 3-4 seconds after. Also, when the temperature final caps off, it falls at a much slower rate than my Fluke thermometer. This is also true for when the temperature rises -- it does so at a much slower rate than the Fluke.
Does anyone know if this could be a software or hardware error?
It might have to do with your sample rate and samples to read setup. I would try taking measurements in Measurement & Automation Explorer using a test panel to see how the test system "reacts" to changes.
Applications Engineering Specialist - Semiconductor Test National Instruments