- TW infrared temperature transmitters
- Setup and support
- Installation guidelines
Proper installation for optimal performance
Each TW sensor has a minimum sensing distance, called the focal distance. The switch cannot reliably detect objects closer than the focal distance.
Spot size vs. target size
At larger measuring distances, the sensing zone - measuring spot size (1) - increases. Therefore, to reliably detect and measure the temperature of the object, it should be larger than the spot size at the measuring distance (2). The sensor takes the average value of all the objects which are within the measurement spot and if the target size is too small, the reading will not be accurate.
Example 1. When the target to be measured is 1,000 mm away from the sensor; the TW's spot diameter is 75 mm. The TW will measure the average temperature of anything within that 75 mm beam.
Example 2. When the target to be measured is 450 mm away from the sensor; the TW's spot diameter is 24.9 mm. This example also has a LED pilot light and the diameter of the pilot light at 450 mm is 20.9 mm. The TW will measure the average temperature of anything within that 24.9 mm beam.
Electrical grounding
Use of a shielded (screened) cable is required for proper operation since the infrared detection technology is susceptible to strong electromagnetic fields.
Caution
- At an ambient temperature > 65 C, the unit must be cooled or protected against the radiated heat by means of a shielding screen.
- When inductive loads are switched: use a free wheel diode.