The panorama pyrometer® CellaTemp® PX 43, realized with a new optical design and without moving parts, has a rectangular measuring field. Due to the quotient measuring method, the measuring field does not need to be fully illuminated by the hot object. Therefore, the wire, for example, may move freely within the measuring field. Nevertheless, the pyrometer permanently delivers a reliable measurement value in milliseconds. The measuring field marking in the through-the-lens sighting or on the monitor in the control room for devices with a video camera shows the exact position and size of the rectangular measuring field.