optris BR 20AR, Operator'S Manual

Page: 24 / 28

-
24
-
4.3 Absolute temperature measurement accuracy
Most IR cameras with 8-
14 μm spectral response are specified with an accuracy of ±2 °C or 2 % of reading
whichever is greater based on deployments in industrial environments in a wide variety of ambient conditions
from 0 °C to 50 °C.
A higher accuracy can only be achieved by using a black body reference source. The source needs to be
stable, have high emissivity and positioned in the scene proximate to the subject to be scanned.
The BR 20AR ambient referencing source can be combined with the PI 450i T010 camera. The black body is
equipped with a 16 bit digital temperature sensor with ±0.1 °C accuracy. By integrating this highly accurate
reference signal to PIX Connect software, the camera uncertainties can be reduced resulting from device
adjustment, ambient temperature drift and short term stability down to a system accuracy of ±0.5 °C with a
confidence interval of 95 %.
The real ability of an IR camera based screening system to detect subjects with fever lies more in the ability to
discern which external face temperatures, as measured at the tear duct/ Medial Canthus, are significantly
higher than those in a given population exposed to similar ambient temperature conditions.