Hi everyone I have two sensors measuring the same quantity, for example air temperature: one instrument is professional the other is a cheap sensor. I have the results of the measurement from an entire day, for example, the professional sensor records data every 2 minutes, the cheap one every 3 minutes.
How can I compare the performances of the two sensors? How can I evaluate the "goodness" of the cheap sensor? What kind of "statistic instrument" can I use?
Can I use Bland-Altman analysis? (if yes can I assume the professional sensor as a "reference sensor" and plot X instead of Y+X/2? )
Thanks
Sensors are charcterized by their specifications. For example: measured quantity, measuring range of this quantity, uncertainty within measuring range, linearity, response time, overrange behaviour, temperature range of operation, humidity range of operation, temperature dependency of measurement, electromagnetic compatibility (EMC) or spill-over from other physical effects. These specifications have to be determined for comparison of the sensors with the requirements of the intended measurement. Comparison of a "cheap" and a "accurate" sensor at special conditions is useless. For instance temperature sensors could provide reasonable indications at room temperature but could generate huge over or underresponses or even completely fail outside during winter time. In metrology responses to quantities have to be calibrated using "standards" which are traceable to national or international standards. Metrology is a science and determing uncertainties is difficult. You can not drive with a Ferrari following a FIAT 500 on a street and "compare" these cars.
Alfred Klett thanks for the answer
Unfortunately I have no access to the sensors, I have only data from a limited range, i.e temperature measurement of some days, for the professional one I have data sheet, for the cheap not even that.
So, I understand I can not validate a sensor with this small amount of data, limited to a restricted range, but it’s all I have.
Limitedly to this small range, can I say something about the “goodness” of the sensor?
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