Kippzonen BSRN Scientific Solar Monitoring System Manuel d'utilisateur télécharger pdf (Page 81)

Figure 8.1. Percentage change in infrared flux due to case thermistor errors.

Using these values, the difference between the measured temperature at a given resistance

and the calculation at that resistance is no more than 0.02 °C through the temperature range

-60 °C to 50 °C. Figure 8.1 illustrates the effect of a positive deviation in the determination

of the case temperature on the calculated ‘case flux’ from the correct value. This difference

may be due to sam pling errors, an incorrect therm istor reading (e.g. the case therm istor is

not representing the actual cold junction temperature) or an incorrect thermistor inversion

equation. As can be seen, unless the error is greater than approximately 5%, the overall accuracy

of the measurement is not greatly affected.

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Kippzonen BSRN Scientific Solar Monitoring System Manuel d'utilisateur Page 81