To satisfy the increasing demand of our customers, the Polaris line of infrared switching units was designed to meet the requirements for a cost-efficient but accurate switching device for the recognition of hot parts. For the precise detection of bright metal parts, the near end spectral sensitivity of the units is important because the infrared energy radiated by such surfaces grows weaker as wavelength increases. Simultaneously, the impact of emissivity deviation on accuracy is much lower in the near end infrared zone.
The units are exceptionally robust due to the fact that the measuring process is performed without mechanically moving parts and because the electronics are housed in a stainless steel cabinet. By utilizing the digital signal process, the Polaris line exceeds standard analog pyrometers in terms of precision and repeatability.
The infrared energy radiated by the target is centered directly on the detector by focusable lenses. Lenses are made of BK7, an optical glass. If additional windows are necessary, they should offer similar optical characteristics.
The optical alignment of the switching device on the measured object is facilitated by precise laser marking which indicates the centre of the measured spot. The optical axis is aligned with the mechanical axis of the sensor housing.
The built-in detector within the infrared Polaris device creates a signal proportional to the infrared radiation which is converted by a microprocessor into a temperature reading and compared with the pre-set switching points. Two switching points can be set independent of each other. The hysteresis of the two switching points is programmable as well as is the switching behaviour itself. One can determine therefore whether the switch is activated/deactivated when the temperature rises or when a certain temperature is exceeded, and whether this procedure is stored should the temperature fall short (temperature decline) of the same temperature value (or of a second, lower temperature value). Polaris supply voltage is available of the two output transistors. This means that there is an electrical connection between hot side of power supply and the individual switching points (if activated). This connection is short-circuit-proof and capable of carrying a maximum of 30mA. In addition, the switching position is indicated by two yellow LEDs on the rear side of the housing.