Those are thermal cameras with a firmware tailored for COVID checkpoints. In other words fever detectors, that's why the t° range's so narrow (and stuck on emisivity of human skin). While you might be able to flash it with the firmware of a general purpose model (UTI165 or 260B - assuming you could find a dump of said firmware), it's very likely full calibration data isn't there to begin with.
I guess you could still use it as-is for short detection even with the displayed t° completely off.