Do you need to calibrate your IR thermometer ?
If you use it just as a diagnostic or troubleshooting tool, probably not. On the other hand, if you are using a fixed sensor for process control, or making critical measurements, you probably should calibrate your thermometer. IR thermometers are calibrated using a black body calibration source. A blackbody calibrator is a calibrated precision temperature source with perfect emissivity. Calibration is performed by pointing the thermometer at the calibrator target, and comparing or  adjusting the output or display. Blackbody sources can cost from a few hundred to
more than $ 20, 000 depending on the temperature range. IRtek provide calibration / verification facility using certified blackbody M400.

Range 50 ~ 400° C ( 122 ~ 752° F)
Accuracy ± 0.8° C at T d 100° C ( ± 1.44° F at T d 212° F)
± 1.6° C at 100° C < T d 200° C ( ± 2.88° F at 212 < T d 392° F)
± 2.8° C at 200° C < T d 400° C ( ± 5.04° F at 392 < T d 752° F)
Stability ± 0.1° C at T d 100° C ( ± 0.18° F at T d 212° F)
± 0.2° C at 100° C < T d 200° C ( ± 0.36° F at 212 < T d 392° F)
± 0.4° C at 200° C < T d 400° C ( ± 0.72° F at 392 < T d 752° F)
Target emissivity 0.95
Resolution 0.1° C ( 0.18° F)
Heating Time 30 minutes to max
Cooling Time 30 minutes to 100° C ( 212° F)
Aperture Diameter 58mm
Power 220VAC( ± 10% ) , 1.25A or 110VAC( ± 10% ) , 2.5A
Size 180 x 114 x 233mm
Weight 3kg